[ { "id": "https://authors.library.caltech.edu/records/fdxcs-prz85", "eprint_id": 119683, "eprint_status": "archive", "datestamp": "2023-08-22 07:53:52", "lastmod": "2023-10-25 16:02:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Park-Ryan-S", "name": { "family": "Park", "given": "Ryan S." }, "orcid": "0000-0001-9896-4585" }, { "id": "Riedel-Joseph-E", "name": { "family": "Riedel", "given": "Joseph E." } }, { "id": "Ermakov-Anton-I", "name": { "family": "Ermakov", "given": "Anton I." }, "orcid": "0000-0002-7020-7061" }, { "id": "Roa-Javier", "name": { "family": "Roa", "given": "Javier" }, "orcid": "0000-0002-0810-1549" }, { "id": "Castillo-Rogez-Julie", "name": { "family": "Castillo-Rogez", "given": "Julie" } }, { "id": "Davies-Ashley-G", "name": { "family": "Davies", "given": "Ashley G." }, "orcid": "0000-0003-1747-8142" }, { "id": "McEwen-Alfred-S", "name": { "family": "McEwen", "given": "Alfred S." }, "orcid": "0000-0001-8638-2553" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" } ] }, "title": "Advanced Pointing Imaging Camera (APIC) for planetary science and mission opportunities", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Astronomy and Astrophysics", "note": "The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The authors like to thank S. Khanna, S. Feldman, and J. Baker for sponsoring the APIC development. The authors would like to thank B. Bills for providing guidance to simplified covariance analysis and A. Konopliv for providing helpful advice. The authors also like to thank all the colleagues who have contributed to this work. Lastly, the authors would like to thank the two anonymous reviewers who have provided helpful comments and suggestions.", "abstract": "The Advanced Pointing Imaging Camera (APIC) is designed to obtain high-resolution imaging data to measure a target's geophysical and geodetic properties. The development of APIC originates from NASA's Homesteader program of technology development for candidate New Frontiers missions. The unique science enabled by APIC derives from its ability to simultaneously take images of the target and star field, allowing high-precision camera pointing knowledge with each high-resolution target image. APIC is small (28 cm \u00d7 18 cm \u00d7 24 cm encompassing volume), light-weight (6 kg total), and moderate in power (13 W maximum) while being high performance and robust to long missions in deep space. APIC incorporates two imagers, one narrow-angle camera (NAC) and one wide-angle camera (WAC) that can operate simultaneously. Both cameras utilize the CMOS-based Mars 2020 Engineering Camera technology with an option of either clear or Red-Green-Blue colors and have wide apertures to enable short exposures and thus perform at a wide range of targets. The NAC has a pixel resolution of 18 \u03bcrad and 4\u00b0 field of view and the WAC has a pixel resolution of 82 \u03bcrad and 18\u00b0 field of view. APIC also has two gimbals, allowing rapid camera pointing updates without the need to change the spacecraft attitude; thus, not interfering with other onboard sensors or spacecraft operations. Both gimbals are capable of compensating for relative spacecraft-target motion (i.e., image motion compensation) with an angular speed of up to 30\u00b0/s (i.e., 0.5 rad/s). Many of APIC components are commercial-off-the-shelf (COTS), or adapted from other NASA flight programs, which makes APIC very competitive in cost and gives it a high technical maturity. APIC's high-resolution images enable the determination of high-accuracy topography for geologic studies. This paper presents details of APIC's characteristics and functionalities as well as specific science objectives that APIC data can address, such as measuring a geometric tidal flexing through estimating the tidal Love number, h\u2082 and l\u2082, and small rotational effects, such as libration and precession, of natural satellites and small bodies (i.e., asteroids and comets) that are key to exploring a planetary body's interior. Improved knowledge of spacecraft orbit via landmark tracking using the APIC data would also improve the recovery of low-degree gravitational parameters such as k\u2082. In this paper, the performance of APIC is presented by showing how well the tidal deformation and libration measurements can be recovered with realistic mission scenarios and configurations.", "date": "2020-12", "date_type": "published", "publication": "Planetary and Space Science", "volume": "194", "publisher": "Elsevier", "pagerange": "Art. No. 105095", "id_number": "CaltechAUTHORS:20230307-21643000.1", "issn": "0032-0633", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21643000.1", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "GALCIT" } ] }, "doi": "10.1016/j.pss.2020.105095", "resource_type": "article", "pub_year": "2020", "author_list": "Park, Ryan S.; Riedel, Joseph E.; et el." }, { "id": "https://authors.library.caltech.edu/records/n6a9v-q2x70", "eprint_id": 119684, "eprint_status": "archive", "datestamp": "2023-08-22 06:08:56", "lastmod": "2023-10-23 17:20:01", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ghobadi-Far-Khosro", "name": { "family": "Ghobadi-Far", "given": "Khosro" }, "orcid": "0000-0001-8146-252X" }, { "id": "Han-Shin-Chan", "name": { "family": "Han", "given": "Shin-Chan" }, "orcid": "0000-0003-1810-1670" }, { "id": "McCullough-Christopher-M", "name": { "family": "McCullough", "given": "Christopher M." }, "orcid": "0000-0001-7424-8349" }, { "id": "Wiese-David-N", "name": { "family": "Wiese", "given": "David N." }, "orcid": "0000-0001-7035-0514" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" }, { "id": "Landerer-Felix-W", "name": { "family": "Landerer", "given": "Felix W." }, "orcid": "0000-0003-2678-095X" }, { "id": "Sauber-Jeanne", "name": { "family": "Sauber", "given": "Jeanne" }, "orcid": "0000-0002-3620-0712" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" } ] }, "title": "GRACE Follow\u2010On Laser Ranging Interferometer Measurements Uniquely Distinguish Short\u2010Wavelength Gravitational Perturbations", "ispublished": "pub", "full_text_status": "public", "keywords": "General Earth and Planetary Sciences; Geophysics", "note": "This work was funded by The University of Newcastle and NASA's GRACE Follow-On science team project. Science team funding was provided by NASA (GRACERFO19-0010) to Jeanne Sauber. We thank Gerhard Heinzel, Henry Wegener, and Vitali M\u00fcller at Albert Einstein Institute for answering our questions on LRI data spectrum. We thank the two anonymous reviewers for their thoughtful and constructive comments which led to a clearer presentation of our work. \n\nData Availability Statement. The GRACE-FO Level-1B and Level-2 data used in this study are publicly available (at https://podaac.jpl.nasa.gov/GRACE), and Earth static gravity field models are available online (at http://icgem.gfz-potsdam.de/tom_longtime).\n\n
", "abstract": "We examined the first-ever laser ranging interferometer (LRI) measurements of inter-satellite tracking acquired by Gravity Recovery and Climate Experiment (GRACE) Follow-On satellites. Through direct along-orbit analysis of instantaneous inter-satellite measurements, we demonstrate the higher sensitivity of LRI (than K-band microwave ranging [KBR]) to anomalies associated with the Earth static gravity field at high spatial resolutions of 100\u2013200 km. We found that LRI captures gravitational signals as small as 0.1 nm/s\u00b2 at 490 km altitude, improved by 1 order of magnitude from KBR. This allows LRI to uniquely detect un-/mis-modeled short-wavelength gravitational perturbations. We employed all LRI data in 2019 to validate various state-of-the-art global static gravity field models and show that LRI measurements, even over 1 month, can distinguish subtle differences among the models computed from ~15 years of GRACE KBR and ~4 years of Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) gradiometry data. Ultra-precise LRI measurements will be yet another critical data set for future gravity field model development.", "date": "2020-08-28", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "47", "number": "16", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2020GL089445", "id_number": "CaltechAUTHORS:20230307-21903000.2", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21903000.2", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "University of Newcastle" }, { "agency": "NASA", "grant_number": "GRACERFO19-0010" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "GALCIT" } ] }, "doi": "10.1029/2020gl089445", "primary_object": { "basename": "Geophysical_Research_Letters_-_2020_-_Ghobadi\u2010Far_-_GRACE_Follow\u2010On_Laser_Ranging_Interferometer_Measurements_Uniquely.pdf", "url": "https://authors.library.caltech.edu/records/n6a9v-q2x70/files/Geophysical_Research_Letters_-_2020_-_Ghobadi\u2010Far_-_GRACE_Follow\u2010On_Laser_Ranging_Interferometer_Measurements_Uniquely.pdf" }, "resource_type": "article", "pub_year": "2020", "author_list": "Ghobadi-Far, Khosro; Han, Shin-Chan; et el." }, { "id": "https://authors.library.caltech.edu/records/cwg68-91274", "eprint_id": 119685, "eprint_status": "archive", "datestamp": "2023-08-22 05:25:42", "lastmod": "2023-10-23 16:20:00", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Landerer-Felix-W", "name": { "family": "Landerer", "given": "Felix W." }, "orcid": "0000-0003-2678-095X" }, { "id": "Flechtner-Frank-M", "name": { "family": "Flechtner", "given": "Frank M." }, "orcid": "0000-0002-3093-5558" }, { "id": "Save-Himanshu", "name": { "family": "Save", "given": "Himanshu" }, "orcid": "0000-0003-4565-9354" }, { "id": "Webb-Frank-H", "name": { "family": "Webb", "given": "Frank H." } }, { "id": "Bandikova-Tamara", "name": { "family": "Bandikova", "given": "Tamara" } }, { "id": "Bertiger-William-I", "name": { "family": "Bertiger", "given": "William I." }, "orcid": "0000-0001-7762-9470" }, { "id": "Bettadpur-Srinivas-V", "name": { "family": "Bettadpur", "given": "Srinivas V." }, "orcid": "0000-0003-3885-2228" }, { "id": "Byun-Sung-Hun", "name": { "family": "Byun", "given": "Sung Hun" } }, { "id": "Dahle-Christoph", "name": { "family": "Dahle", "given": "Christoph" }, "orcid": "0000-0002-4733-9242" }, { "id": "Dobslaw-Henryk", "name": { "family": "Dobslaw", "given": "Henryk" }, "orcid": "0000-0003-1776-3314" }, { "id": "Fahnestock-Eugene", "name": { "family": "Fahnestock", "given": "Eugene" } }, { "id": "Harvey-Nate", "name": { "family": "Harvey", "given": "Nate" } }, { "id": "Kang-Zhigui", "name": { "family": "Kang", "given": "Zhigui" } }, { "id": "Kruizinga-Gerhard-L", "name": { "family": "Kruizinga", "given": "Gerhard L. H." }, "orcid": "0000-0002-9301-4692" }, { "id": "Loomis-Bryant-D", "name": { "family": "Loomis", "given": "Bryant D." }, "orcid": "0000-0002-9370-9160" }, { "id": "McCullough-Christopher", "name": { "family": "McCullough", "given": "Christopher" }, "orcid": "0000-0001-7424-8349" }, { "id": "Murb\u00f6ck-Michael", "name": { "family": "Murb\u00f6ck", "given": "Michael" }, "orcid": "0000-0002-4108-578X" }, { "id": "Nagel-Peter", "name": { "family": "Nagel", "given": "Peter" }, "orcid": "0000-0002-1398-2985" }, { "id": "Paik-Meegyeong", "name": { "family": "Paik", "given": "Meegyeong" }, "orcid": "0000-0002-3950-894X" }, { "id": "Pie-Nadege", "name": { "family": "Pie", "given": "Nadege" }, "orcid": "0000-0001-9163-7856" }, { "id": "Poole-Steve", "name": { "family": "Poole", "given": "Steve" } }, { "id": "Strekalov-Dmitry-V", "name": { "family": "Strekalov", "given": "Dmitry" }, "orcid": "0000-0001-6058-7390" }, { "id": "Tamisiea-Mark-E", "name": { "family": "Tamisiea", "given": "Mark E." } }, { "id": "Wang-Furun", "name": { "family": "Wang", "given": "Furun" } }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Wen-Hui-Ying", "name": { "family": "Wen", "given": "Hui-Ying" } }, { "id": "Wiese-David-N", "name": { "family": "Wiese", "given": "David N." }, "orcid": "0000-0001-7035-0514" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" } ] }, "title": "Extending the Global Mass Change Data Record: GRACE Follow\u2010On Instrument and Science Data Performance", "ispublished": "pub", "full_text_status": "public", "keywords": "General Earth and Planetary Sciences; Geophysics", "note": "GRACE-FO is a partnership between NASA and the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences. The twin GRACE-FO spacecraft are operated from the German Space Operations Center in Oberpfaffenhofen, Germany, under a GFZ contract with the German Aerospace Center. JPL manages the mission for NASA's Science Mission Directorate at NASA Headquarters in Washington. Caltech in Pasadena, California, manages JPL for NASA. This work represents research carried out at the Jet Propulsion Laboratory/California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The preparation of the GFZ contribution to the GRACE-FO Science Data System was funded by the German Ministry for Education and Research (BMBF) under grant 03F0654A. Part of this work described in this paper was carried out at UT-CSR under JPL Contract 1604489. The use of the facilities of the Texas Advanced Computational Center (TACC) is acknowledged. We thank Natthachet Tangdamrongsub and an anonymous reviewer for their constructive comments. \n\nData Availability Statement. More information about GRACE-FO can be found at https://gracefo.jpl.nasa.gov and at https://www.gfz-potsdam.de/en/grace-fo. GRACE and GRACE-FO Level-1 data, Level 2 spherical harmonic gravity coefficients and the Technical Notes TN-13 and TN-14 are available at NASA's PO.DAAC (https://podaac.jpl.nasa.gov), and GFZ's ISDC (https://isdc.gfz-potsdam.de/grace-fo-isdc/). All handbooks are available at https://podaac-tools.jpl.nasa.gov/drive/files/allData/gracefo/docs/.\n\n", "abstract": "Since June, 2018, the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) is extending the 15-year monthly mass change record of the GRACE mission, which ended in June 2017. The GRACE-FO instrument and flight system performance has improved over GRACE. Better attitude solutions and enhanced pointing performance result in reduced fuel consumption and gravity range rate post-fit residuals. One accelerometer requires additional calibrations due to unexpected measurement noise. The GRACE-FO gravity and mass change fields from June 2018 through December 2019 continue the GRACE record at an equivalent precision and spatiotemporal sampling. During this period, GRACE-FO observed large interannual terrestrial water variations associated with excess rainfall (Central US, Middle East), drought (Europe, Australia), and ice melt (Greenland). These observations are consistent with independent mass change estimates, providing high confidence that no intermission biases exist from GRACE to GRACE-FO, despite the 11-month gap. GRACE-FO has also successfully demonstrated satellite-to-satellite laser ranging interferometry.", "date": "2020-06-28", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "47", "number": "12", "publisher": "American Geophysical Union", "pagerange": "Art. no. e2020GL088306", "id_number": "CaltechAUTHORS:20230307-21910000.4", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21910000.4", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "GFZ German Research Centre for Geosciences" }, { "agency": "NASA/JPL/Caltech" }, { "agency": "Bundesministerium f\u00fcr Bildung und Forschung (BMBF)", "grant_number": "03F0654A" }, { "agency": "JPL", "grant_number": "1604489" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "GALCIT" } ] }, "doi": "10.1029/2020gl088306", "primary_object": { "basename": "Geophysical_Research_Letters_-_2020_-_Landerer_-_Extending_the_Global_Mass_Change_Data_Record__GRACE_Follow\u2010On_Instrument.pdf", "url": "https://authors.library.caltech.edu/records/cwg68-91274/files/Geophysical_Research_Letters_-_2020_-_Landerer_-_Extending_the_Global_Mass_Change_Data_Record__GRACE_Follow\u2010On_Instrument.pdf" }, "resource_type": "article", "pub_year": "2020", "author_list": "Landerer, Felix W.; Flechtner, Frank M.; et el." }, { "id": "https://authors.library.caltech.edu/records/rr9ek-6s723", "eprint_id": 119686, "eprint_status": "archive", "datestamp": "2023-08-22 01:31:58", "lastmod": "2023-10-25 16:02:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tapley-Byron-D", "name": { "family": "Tapley", "given": "Byron D." }, "orcid": "0000-0003-3689-5750" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Flechtner-Frank", "name": { "family": "Flechtner", "given": "Frank" }, "orcid": "0000-0002-3093-5558" }, { "id": "Reigber-Christoph", "name": { "family": "Reigber", "given": "Christoph" }, "orcid": "0000-0001-9036-1499" }, { "id": "Bettadpur-Srinivas", "name": { "family": "Bettadpur", "given": "Srinivas" }, "orcid": "0000-0003-3885-2228" }, { "id": "Rodell-Matthew", "name": { "family": "Rodell", "given": "Matthew" }, "orcid": "0000-0003-0106-7437" }, { "id": "Sasgen-Ingo", "name": { "family": "Sasgen", "given": "Ingo" }, "orcid": "0000-0002-8993-0989" }, { "id": "Famiglietti-James-S", "name": { "family": "Famiglietti", "given": "James S." }, "orcid": "0000-0002-6053-5379" }, { "id": "Landerer-Felix-W", "name": { "family": "Landerer", "given": "Felix W." }, "orcid": "0000-0003-2678-095X" }, { "id": "Chambers-Don-P", "name": { "family": "Chambers", "given": "Don P." }, "orcid": "0000-0002-5439-0257" }, { "id": "Reager-John-T", "name": { "family": "Reager", "given": "John T." }, "orcid": "0000-0001-7575-2520" }, { "id": "Gardner-Alex-S", "name": { "family": "Gardner", "given": "Alex S." }, "orcid": "0000-0002-8394-8889" }, { "id": "Save-Himanshu", "name": { "family": "Save", "given": "Himanshu" }, "orcid": "0000-0003-4565-9354" }, { "id": "Ivins-Erik-R", "name": { "family": "Ivins", "given": "Erik R." }, "orcid": "0000-0003-0148-357X" }, { "id": "Swenson-Sean-C", "name": { "family": "Swenson", "given": "Sean C." }, "orcid": "0000-0002-2923-1203" }, { "id": "Boening-Carmen", "name": { "family": "Boening", "given": "Carmen" } }, { "id": "Dahle-Christoph", "name": { "family": "Dahle", "given": "Christoph" }, "orcid": "0000-0002-4733-9242" }, { "id": "Wiese-David-N", "name": { "family": "Wiese", "given": "David N." }, "orcid": "0000-0001-7035-0514" }, { "id": "Dobslaw-Henryk", "name": { "family": "Dobslaw", "given": "Henryk" }, "orcid": "0000-0003-1776-3314" }, { "id": "Tamisiea-Mark-E", "name": { "family": "Tamisiea", "given": "Mark E." } }, { "id": "Velicogna-Isabella", "name": { "family": "Velicogna", "given": "Isabella" }, "orcid": "0000-0002-9020-1898" } ] }, "title": "Contributions of GRACE to understanding climate change", "ispublished": "pub", "full_text_status": "public", "keywords": "Social Sciences (miscellaneous); Environmental Science (miscellaneous)", "note": "The authors acknowledge the influence of J. M. Wahr (formerly of the University of Colorado Boulder, USA) making fundamental contributions, both in theoretical concept and in measurement applications, to the success of the GRACE mission. \n\nC.D., H.D. und F.F. acknowledge funding of the development of the GRACE-Follow On Science Data System by the German Federal Ministry of Education and Research (BMBF) under grant 03F0654A. I.S. acknowledges funding by the Helmholtz Climate Initiative REKLIM (Regional Climate Change), a joint research project of the Helmholtz Association of German Research Centres (HGF) and the German Research Foundation (DFG) through grant SA 1734/4-1. A.G. received funding from the NASA Cryosphere Science program. M.E.T. was supported by CSR discretionary funds. \n\nData availability\nThe GRACE data used in this paper are freely available from the websites of the Science Data Systems Centres. The GRACE gravity field data products (Level 2 data) as well as supporting documentation may be accessed at http://podaac.jpl.nasa.gov/grace and http://isdc.gfz-potsdam.de/grace. User-friendly, gridded maps of mass change (Level 3 data) are available from https://grace.jpl.nasa.gov/ (JPL), http://www2.csr.utexas.edu/grace/ (CSR) and http://gravis.gfz-potsdam.de/home (GFZ). GRACE Follow-On data will be provided through the same portals once available. The reader is encouraged to use all data sets available.\n\nA list of GRACE-related publications is available under https://grace.jpl.nasa.gov/publications/ and https://www.gfz-potsdam.de/en/grace/. Videos of the GRACE-Follow On pre-launch briefing and the launch are available under https://www.youtube.com/watch?v=qYJt-6uHVcM and https://www.youtube.com/watch?v=I_0GgKfwCSk, respectively (both sources last accessed September 15, 2018).\n\nThe figures and updates to published values presented in this paper are based on the following data sets and processing.\n\nFigure 1: the plot is based on the 1-arc degree mascon solution by CSR RL05M5. A linear trend, annual and semi-annual model is fit to each pixel for the entire mission duration, assuming temporally uniform uncertainties. The temporal linear part of that fit is mapped in a and b the standard deviation shown in c is calculated after the removal of the temporal linear trend. The trends have been corrected for glacial-isostatic adjustment using the ICE5G model of Peltier et al.13 computed by A et al.125.\n\nFigure 2 and 'Ice sheets and glaciers': time series of ice-sheet mass change are based on GRACE Level 2 data of CSR RL05 obtained with an inversion approach based on forward modelling19,126. For Antarctica the GIA correction is AGE1 (ref. 126) (48 \u00b1 28 Gt yr\u20131), for Greenland it is GGG1D (ref. 127)(17 Gt yr\u20131). Uncertainties are calculated based on the formal monthly uncertainties provided by the processing centres, scaled by the root mean square (RMS) residual after subtracting temporal fluctuations longer than three months. Temporal linear trends for the entire GRACE period are estimated using uncertainty-weighted least squares. Annual balances are estimated using an unweighted piecewise linear model with breakpoints on 1 January. Uncertainties for the temporal linear trends and the annual balances are obtained by error propagation.\n\nFigure 3 and 'Terrestrial water storage': time series of the zonal mean of terrestrial water storage anomalies in mid-latitudes are based on CSR RL05M Mascons5. Uncertainties are calculated as RMS residual of the zonal mean after subtracting the linear trend, offset, annual and sub-annual temporal components and fluctuations longer than five months. The RMS uncertainty (2 cm equivalent water height along the latitude, 2\u03c3) is then used to scale the formal, time-dependent uncertainties provided by the processing centre CSR. Then the temporal model is refit and propagated uncertainties are calculated. The annual amplitude is shown on the right part of the figure. The anomalies shown in the left part of the figure are the residuals with respect to the fitted temporal model.\n\nFigure 4 and 'Sea-level change and ocean dynamics': Global Mean Sea-level (GMSL) and its components. GSML from altimetry is based on data provided by the University of Colorado (http://sealevel/colorado.edu)89. Ocean mass changes are derived from GRACE Level 2 data of three processing centres (CSR RL05, JPL RL05 and GFZ RL05) using an averaging kernel method and scaling100, available from the University of South Florida (http://xena.marine.usf.edu/~chambers/SatLab/Home.html). Global mean steric sea level anomalies are based on Argo data provided by the National Oceanic and Atmospheric Administration (NOAA; https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/basin_fsl_data.html). To unify the temporal sampling, we adopt three-month (seasonal) averages, which is limited by the sampling period of the Argo data obtained from NOAA. These were computed after first fitting and removing annual and semi-annual sinusoids from the altimetry and GRACE monthly averages. An annual and semi-annual sinusoid was also estimated and removed from the three-month thermometric time-series for consistency. The correction for glacial-isostatic adjustment to the GRACE data is based on the ICE5G ice model13, computed by A et al.125. Further details can be found in Chambers et al.94.", "abstract": "Time-resolved satellite gravimetry has revolutionized understanding of mass transport in the Earth system. Since 2002, the Gravity Recovery and Climate Experiment (GRACE) has enabled monitoring of the terrestrial water cycle, ice sheet and glacier mass balance, sea level change and ocean bottom pressure variations, as well as understanding responses to changes in the global climate system. Initially a pioneering experiment of geodesy, the time-variable observations have matured into reliable mass transport products, allowing assessment and forecast of a number of important climate trends, and improvements in service applications such as the United States Drought Monitor. With the successful launch of the GRACE Follow-On mission, a multi-decadal record of mass variability in the Earth system is within reach.", "date": "2019-05", "date_type": "published", "publication": "Nature Climate Change", "volume": "9", "number": "5", "publisher": "Nature Publishing Group", "pagerange": "358-369", "id_number": "CaltechAUTHORS:20230307-21924000.5", "issn": "1758-678X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21924000.5", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Bundesministerium f\u00fcr Bildung und Forschung (BMBF)", "grant_number": "03F0654A" }, { "agency": "Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF)" }, { "agency": "Deutsche Forschungsgemeinschaft (DFG)", "grant_number": "SA 1734/4-1" }, { "agency": "University of Texas at Austin" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "GALCIT" } ] }, "doi": "10.1038/s41558-019-0456-2", "resource_type": "article", "pub_year": "2019", "author_list": "Tapley, Byron D.; Watkins, Michael M.; et el." }, { "id": "https://authors.library.caltech.edu/records/q9bme-z1w76", "eprint_id": 119687, "eprint_status": "archive", "datestamp": "2023-08-22 00:15:46", "lastmod": "2023-10-25 16:02:44", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sclegel-Nicole-Jeanne", "name": { "family": "Schlegel", "given": "Nicole-Jeanne" }, "orcid": "0000-0001-8035-448X" }, { "id": "Seroussi-Helene", "name": { "family": "Seroussi", "given": "Helene" }, "orcid": "0000-0001-9201-1644" }, { "id": "Schodlok-Michael-P", "name": { "family": "Schodlok", "given": "Michael P." }, "orcid": "0000-0002-2479-2079" }, { "id": "Larour-Eric-Y", "name": { "family": "Larour", "given": "Eric Y." }, "orcid": "0000-0002-4009-4238" }, { "id": "Boening-Carmen", "name": { "family": "Boening", "given": "Carmen" } }, { "id": "Limonadi-Daniel", "name": { "family": "Limonadi", "given": "Daniel" }, "orcid": "0000-0001-8736-4461" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Morlighem-Mathieu", "name": { "family": "Morlighem", "given": "Mathieu" }, "orcid": "0000-0001-5219-1310" }, { "id": "van-den-Broeke-Michiel-R", "name": { "family": "van den Broeke", "given": "Michiel R." }, "orcid": "0000-0003-4662-7565" } ] }, "title": "Exploration of Antarctic Ice Sheet 100-year contribution to sea level rise and associated model uncertainties using the ISSM framework", "ispublished": "pub", "full_text_status": "public", "keywords": "Earth-Surface Processes; Water Science and Technology", "note": "\u00a9 Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. \n\nThe research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Funding was provided by grants from Jet Propulsion Laboratory Research Technology and Development and from NASA Cryospheric Science, Interdisciplinary Research in Earth Science and Modeling, Analysis and Prediction (MAP) programs. We gratefully acknowledge computational resources and support from the NASA Advanced Supercomputing Division. Michiel R. van den Broeke acknowledges support from the Netherlands Earth System Science Centre (NESSC). This work was made possible through model development of the ISSM team. The authors would also like to thank Amy Braverman for her statistical insight and discussions on model uncertainty. \n\nAuthor contributions. All authors discussed results presented in this paper. NJS led the design, execution, and analysis of ISSM UQ experiments. HS was responsible for mesh resolution sensitivity runs, determination of IB sampling bounds, and analysis of results. MPS was responsible for all ocean model runs and determination of ice shelf basal melt sampling bounds. EYL was in charge of the original design and implementation of parallel DAKOTA within ISSM. CB, DL, and MMW managed the UQ tasks and were involved in developing and guiding the scientific strategy for this project. MM contributed MC bedrock topography and development of L1L2 stress balance approximation within ISSM. MRvdB contributed RACMO2.1 estimates of SMB and associated components. \n\nCode and data availability. RACMO2.1 model output used in this study (Lenaerts et al., 2012) is available from m.r.vandenBroeke@uu.nl upon request. ISSM model output used in this study is available from the ISSM model team (issm@jpl.nasa.gov or http://issm.jpl.nasa.gov/contactus/, last access: 9 August 2017) or from schlegel@jpl.nasa.gov upon request. The MATLAB code used to analyze model results is also available from schlegel@jpl.nasa.gov upon request. The MC bed topography product is currently under preparation for public release, and more details regarding the product and its release can be obtained from mathieu.morlighem@uci.edu. The ocean model output used in this study is currently under preparation for public release. Details can be obtained from schodlok@jpl.nasa.gov. \n\nThe authors declare that they have no conflict of interest.\n\nPublished - tc-12-3511-2018.pdf
Supplemental Material - tc-12-3511-2018-supplement.pdf
", "abstract": "Abstract. Estimating the future evolution of the Antarctic Ice Sheet (AIS) is critical for improving future sea level rise (SLR) projections. Numerical ice sheet models are invaluable tools for bounding Antarctic vulnerability; yet, few continental-scale projections of century-scale AIS SLR contribution exist, and those that do vary by up to an order of magnitude. This is partly because model projections of future sea level are inherently uncertain and depend largely on the model's boundary conditions and climate forcing, which themselves are unknown due to the uncertainty in the projections of future anthropogenic emissions and subsequent climate response. Here, we aim to improve the understanding of how uncertainties in model forcing and boundary conditions affect ice sheet model simulations. With use of sampling techniques embedded within the Ice Sheet System Model (ISSM) framework, we assess how uncertainties in snow accumulation, ocean-induced melting, ice viscosity, basal friction, bedrock elevation, and the presence of ice shelves impact continental-scale 100-year model simulations of AIS future sea level contribution. Overall, we find that AIS sea level contribution is strongly affected by grounding line retreat, which is driven by the magnitude of ice shelf basal melt rates and by variations in bedrock topography. In addition, we find that over 1.2\u2009m of AIS global mean sea level contribution over the next century is achievable, but not likely, as it is tenable only in response to unrealistically large melt rates and continental ice shelf collapse. Regionally, we find that under our most extreme 100-year warming experiment generalized for the entire ice sheet, the Amundsen Sea sector is the most significant source of model uncertainty (1032\u2009mm 6\u03c3 spread) and the region with the largest potential for future sea level contribution (297\u2009mm). In contrast, under a more plausible forcing informed regionally by literature and model sensitivity studies, the Ronne basin has a greater potential for local increases in ice shelf basal melt rates. As a result, under this more likely realization, where warm waters reach the continental shelf under the Ronne ice shelf, it is the Ronne basin, particularly the Evans and Rutford ice streams, that are the greatest contributors to potential SLR (161\u2009mm) and to simulation uncertainty (420\u2009mm 6\u03c3 spread).", "date": "2018-11", "date_type": "published", "publication": "Cryosphere", "volume": "12", "number": "11", "publisher": "European Geosciences Union", "pagerange": "3511-3534", "id_number": "CaltechAUTHORS:20230307-21929000.6", "issn": "1994-0424", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21929000.6", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "Netherlands Earth System Science Centre" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "GALCIT" } ] }, "doi": "10.5194/tc-12-3511-2018", "primary_object": { "basename": "tc-12-3511-2018-supplement.pdf", "url": "https://authors.library.caltech.edu/records/q9bme-z1w76/files/tc-12-3511-2018-supplement.pdf" }, "related_objects": [ { "basename": "tc-12-3511-2018.pdf", "url": "https://authors.library.caltech.edu/records/q9bme-z1w76/files/tc-12-3511-2018.pdf" } ], "resource_type": "article", "pub_year": "2018", "author_list": "Schlegel, Nicole-Jeanne; Seroussi, Helene; et el." }, { "id": "https://authors.library.caltech.edu/records/k18hk-ss764", "eprint_id": 119689, "eprint_status": "archive", "datestamp": "2023-08-22 18:57:40", "lastmod": "2023-10-25 16:44:52", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zuber-Maria-T", "name": { "family": "Zuber", "given": "Maria T." }, "orcid": "0000-0003-2652-8017" }, { "name": { "family": "Smith", "given": "D. E." } }, { "name": { "family": "Neumann", "given": "G. A." }, "orcid": "0000-0003-0644-9944" }, { "name": { "family": "Goossens", "given": "S." } }, { "name": { "family": "Andrews-Hanna", "given": "J. C." }, "orcid": "0000-0001-9374-7776" }, { "name": { "family": "Head", "given": "J. W." }, "orcid": "0000-0003-2013-560X" }, { "name": { "family": "Kiefer", "given": "W. S." }, "orcid": "0000-0001-6741-5460" }, { "id": "Asmar-Sami-W", "name": { "family": "Asmar", "given": "Sami W." }, "orcid": "0000-0002-9912-645X" }, { "id": "Konopliv-Alexander-S", "name": { "family": "Konopliv", "given": "Alexander S." }, "orcid": "0000-0001-8669-1866" }, { "name": { "family": "Lemoine", "given": "F. G." }, "orcid": "0000-0002-3051-1456" }, { "name": { "family": "Matsuyama", "given": "I." }, "orcid": "0000-0002-2917-8633" }, { "name": { "family": "Melosh", "given": "H. J." }, "orcid": "0000-0003-1881-1496" }, { "name": { "family": "McGovern", "given": "P. J." }, "orcid": "0000-0001-9647-3096" }, { "name": { "family": "Nimmo", "given": "F." }, "orcid": "0000-0003-3573-5915" }, { "name": { "family": "Phillips", "given": "R. J." }, "orcid": "0000-0001-5869-7427" }, { "name": { "family": "Solomon", "given": "S. C." }, "orcid": "0000-0001-8328-7251" }, { "name": { "family": "Taylor", "given": "G. J." }, "orcid": "0000-0001-9471-3359" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "name": { "family": "Wieczorek", "given": "M. A." }, "orcid": "0000-0001-7007-4222" }, { "id": "Williams-James-G", "name": { "family": "Williams", "given": "James G." } }, { "name": { "family": "Jansen", "given": "J. C." }, "orcid": "0000-0003-1180-9078" }, { "name": { "family": "Johnson", "given": "B. C." }, "orcid": "0000-0002-4267-093X" }, { "name": { "family": "Keane", "given": "J. T." }, "orcid": "0000-0002-4803-5793" }, { "name": { "family": "Mazarico", "given": "E." }, "orcid": "0000-0003-3456-427X" }, { "name": { "family": "Miljkovi\u0107", "given": "K." }, "orcid": "0000-0001-8644-8903" }, { "id": "Park-Ryan-S", "name": { "family": "Park", "given": "Ryan S." }, "orcid": "0000-0001-9896-4585" }, { "name": { "family": "Soderblom", "given": "J. M." }, "orcid": "0000-0003-3715-6407" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" } ] }, "title": "Gravity field of the Orientale basin from the Gravity Recovery and Interior Laboratory Mission", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "note": "The GRAIL mission is supported by NASA's Discovery Program and is performed under contract to the Massachusetts Institute of Technology and the Jet Propulsion Laboratory. Topography was obtained from the Lunar Orbiter Laser Altimeter on the Lunar Reconnaissance Mission, managed by NASA's Goddard Space Flight Center. The NASA Pleiades and Center for Climate Simulation supercomputers were used to compute the gravity solutions. All data used in this study are archived in the Geosciences Node of the NASA Planetary Data System at http://geo.pds.nasa.gov/missions/grail/default.htm.", "abstract": "The Orientale basin is the youngest and best-preserved major impact structure on the Moon. We used the Gravity Recovery and Interior Laboratory (GRAIL) spacecraft to investigate the gravitational field of Orientale at 3- to 5-kilometer (km) horizontal resolution. A volume of at least (3.4 \u00b1 0.2) \u00d7 106 km3 of crustal material was removed and redistributed during basin formation. There is no preserved evidence of the transient crater that would reveal the basin's maximum volume, but its diameter may now be inferred to be between 320 and 460 km. The gravity field resolves distinctive structures of Orientale's three rings and suggests the presence of faults associated with the outer two that penetrate to the mantle. The crustal structure of Orientale provides constraints on the formation of multiring basins.", "date": "2016-10-28", "date_type": "published", "publication": "Science", "volume": "354", "number": "6311", "publisher": "American Association for the Advancement of Science", "pagerange": "438-441", "id_number": "CaltechAUTHORS:20230307-21967000.8", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21967000.8", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "GALCIT" } ] }, "doi": "10.1126/science.aag0519", "resource_type": "article", "pub_year": "2016", "author_list": "Zuber, Maria T.; Smith, D. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/vzq1r-8ny08", "eprint_id": 119690, "eprint_status": "archive", "datestamp": "2023-08-22 18:40:16", "lastmod": "2023-10-25 16:44:54", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schlegel-Nicole-Jeanne", "name": { "family": "Schlegel", "given": "Nicole-Jeanne" }, "orcid": "0000-0001-8035-448X" }, { "id": "Wiese-David-N", "name": { "family": "Wiese", "given": "David N." }, "orcid": "0000-0001-7035-0514" }, { "id": "Larour-Eric-Y", "name": { "family": "Larour", "given": "Eric Y." }, "orcid": "0000-0002-4009-4238" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Box-Jason-E", "name": { "family": "Box", "given": "Jason E." }, "orcid": "0000-0003-0052-8705" }, { "id": "Fettweis-Xavier", "name": { "family": "Fettweis", "given": "Xavier" }, "orcid": "0000-0002-4140-3813" }, { "id": "van-den-Broeke-Michiel-R", "name": { "family": "van den Broeke", "given": "Michiel R." }, "orcid": "0000-0003-4662-7565" } ] }, "title": "Application of GRACE to the assessment of model-based estimates of monthly Greenland Ice Sheet mass balance\u00a0(2003\u20132012)", "ispublished": "pub", "full_text_status": "public", "keywords": "Earth-Surface Processes; Water Science and Technology", "note": "\u00a9 Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 License. \n\nThis work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Cryosphere Program. The contribution from J. E. Box was supported by Geocenter Denmark. The authors would like to acknowledge the data provided by the National Snow and Ice Data Center DAAC, University of Colorado, Boulder, CO, Operation IceBridge, as well as CReSIS data generated from NSF grant ANT-0424589 and NASA grant NNX10AT68G (Gogineni, 2012). This work was made possible through model development of the ISSM team, including invaluable guidance in model setup by Helene Seroussi and incorporation of the most recent BedMachine bedmap of Greenland provided by Mathieu Morlighem. The authors would also like to thank Alex Gardner for his invaluable contribution, including discussion and advice pertaining to the periphery; GRACE_JPL team members, in particular Carmen Boening and Isabella Velicogna, for their support and advice with respect to interpretation of the GRACE solution; and Beata Csatho for sharing results of altimetrically derived trends over the Greenland Ice Sheet. Finally, the authors would like to extend gratitude towards four anonymous referees for their helpful comments and discussions pertaining to this paper.\n\nPublished - tc-10-1965-2016.pdf
Supplemental Material - tc-10-1965-2016-supplement.pdf
", "abstract": "Abstract. Quantifying the Greenland Ice Sheet's future contribution to sea level rise is a challenging task that requires accurate estimates of ice sheet sensitivity to climate change. Forward ice sheet models are promising tools for estimating future ice sheet behavior, yet confidence is low because evaluation of historical simulations is challenging due to the scarcity of continental-wide data for model evaluation. Recent advancements in processing of Gravity Recovery and Climate Experiment\u00a0(GRACE) data using Bayesian-constrained mass concentration\u00a0(\"mascon\") functions have led to improvements in spatial resolution and noise reduction of monthly global gravity fields. Specifically, the Jet Propulsion Laboratory's JPL RL05M GRACE mascon solution\u00a0(GRACE_JPL) offers an opportunity for the assessment of model-based estimates of ice sheet mass balance\u00a0(MB) at \u223c\u2009300\u202fkm spatial scales. Here, we quantify the differences between Greenland monthly observed MB\u00a0(GRACE_JPL) and that estimated by state-of-the-art, high-resolution models, with respect to GRACE_JPL and model uncertainties. To simulate the years 2003\u20132012, we force the Ice Sheet System Model\u00a0(ISSM) with anomalies from three different surface mass balance\u00a0(SMB) products derived from regional climate models. Resulting MB is compared against GRACE_JPL within individual mascons. Overall, we find agreement in the northeast and southwest where MB is assumed to be primarily controlled by SMB. In the interior, we find a discrepancy in trend, which we presume to be related to millennial-scale dynamic thickening not considered by our model. In the northwest, seasonal amplitudes agree, but modeled mass trends are muted relative to GRACE_JPL. Here, discrepancies are likely controlled by temporal variability in ice discharge and other related processes not represented by our model simulations, i.e.,\u00a0hydrological processes and ice\u2013ocean interaction. In the southeast, GRACE_JPL exhibits larger seasonal amplitude than predicted by the models while simultaneously having more pronounced trends; thus, discrepancies are likely controlled by a combination of missing processes and errors in both the SMB products and ISSM. At the margins, we find evidence of consistent intra-annual variations in regional MB that deviate distinctively from the SMB annual cycle. Ultimately, these monthly-scale variations, likely associated with hydrology or ice\u2013ocean interaction, contribute to steeper negative mass trends observed by GRACE_JPL. Thus, models should consider such processes at relatively high (monthly-to-seasonal) temporal resolutions to achieve accurate estimates of Greenland\u00a0MB.", "date": "2016-09-07", "date_type": "published", "publication": "Cryosphere", "volume": "10", "number": "5", "publisher": "European Geosciences Union", "pagerange": "1965-1989", "id_number": "CaltechAUTHORS:20230307-21978000.9", "issn": "1994-0424", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21978000.9", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "Geocenter Denmark" }, { "agency": "NSF", "grant_number": "ANT-0424589" }, { "agency": "NASA", "grant_number": "NNX10AT68G" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "GALCIT" } ] }, "doi": "10.5194/tc-10-1965-2016", "primary_object": { "basename": "tc-10-1965-2016-supplement.pdf", "url": "https://authors.library.caltech.edu/records/vzq1r-8ny08/files/tc-10-1965-2016-supplement.pdf" }, "related_objects": [ { "basename": "tc-10-1965-2016.pdf", "url": "https://authors.library.caltech.edu/records/vzq1r-8ny08/files/tc-10-1965-2016.pdf" } ], "resource_type": "article", "pub_year": "2016", "author_list": "Schlegel, Nicole-Jeanne; Wiese, David N.; et el." }, { "id": "https://authors.library.caltech.edu/records/y6bdr-hy159", "eprint_id": 119691, "eprint_status": "archive", "datestamp": "2023-08-22 18:38:40", "lastmod": "2023-10-23 20:15:55", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wiese-David-N", "name": { "family": "Wiese", "given": "David N." }, "orcid": "0000-0001-7035-0514" }, { "id": "Landerer-Felix-W", "name": { "family": "Landerer", "given": "Felix W." }, "orcid": "0000-0003-2678-095X" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" } ] }, "title": "Quantifying and reducing leakage errors in the JPL RL05M GRACE mascon solution", "ispublished": "pub", "full_text_status": "public", "keywords": "Water Science and Technology", "note": "The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The JPL RL05M solution with the CRI filter implemented, along with the associated scale factors are available via the Physical Oceanography Distributed Archive Center (PODAAC) as well as the GRACE Tellus websites.\n\n", "abstract": "Recent advances in processing data from the Gravity Recovery and Climate Experiment (GRACE) have led to a new generation of gravity solutions constrained within a Bayesian framework to remove correlated errors rather than relying on empirical filters. The JPL RL05M mascon solution is one such solution, solving for mass variations using spherical cap mass concentration elements (mascons), while relying on external information provided by near-global geophysical models to constrain the solution. This new gravity solution is fundamentally different than the traditional spherical harmonic gravity solution, and as such, requires different care when postprocessing. Here we discuss two classes of postprocessing considerations for the JPL RL05M GRACE mascon solution: (1) reducing leakage errors across land/ocean boundaries, and (2) scaling the solutions to account for leakage errors introduced through parameterizing the gravity solution in terms of mascons. A Coastline Resolution Improvement (CRI) filter is developed to reduce leakage errors across coastlines. Synthetic simulations reveal a reduction in leakage errors of \u223c50%, such that residual leakage errors are \u223c1 cm equivalent water height (EWH) averaged globally. A set of gain factors is derived to reduce leakage errors for continental hydrology applications. The combined effect of the CRI filter coupled with application of the gain factors, is shown to reduce leakage errors when determining the mass balance of large (>160,000 km\u00b2) hydrological basins from 11% to 30% (0.6\u20131.5 mm EWH) averaged globally, with local improvements up to 38%\u201381% (9\u201319 mm EWH).", "date": "2016-09", "date_type": "published", "publication": "Water Resources Research", "volume": "52", "number": "9", "publisher": "American Geophysical Union", "pagerange": "7490-7502", "id_number": "CaltechAUTHORS:20230307-21982000.10", "issn": "0043-1397", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21982000.10", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "GALCIT" } ] }, "doi": "10.1002/2016wr019344", "primary_object": { "basename": "Water_Resources_Research_-_2016_-_Wiese_-_Quantifying_and_reducing_leakage_errors_in_the_JPL_RL05M_GRACE_mascon_solution.pdf", "url": "https://authors.library.caltech.edu/records/y6bdr-hy159/files/Water_Resources_Research_-_2016_-_Wiese_-_Quantifying_and_reducing_leakage_errors_in_the_JPL_RL05M_GRACE_mascon_solution.pdf" }, "resource_type": "article", "pub_year": "2016", "author_list": "Wiese, David N.; Landerer, Felix W.; et el." }, { "id": "https://authors.library.caltech.edu/records/dbvj5-dej19", "eprint_id": 119692, "eprint_status": "archive", "datestamp": "2023-08-22 16:41:11", "lastmod": "2023-10-23 20:14:53", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Landerer-Felix-W", "name": { "family": "Landerer", "given": "Felix W." }, "orcid": "0000-0003-2678-095X" }, { "id": "Wiese-David-N", "name": { "family": "Wiese", "given": "David N." }, "orcid": "0000-0001-7035-0514" }, { "id": "Bentel-Katrin", "name": { "family": "Bentel", "given": "Katrin" }, "orcid": "0000-0003-0026-3268" }, { "id": "Boening-Carmen", "name": { "family": "Boening", "given": "Carmen" } }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" } ] }, "title": "North Atlantic meridional overturning circulation variations from GRACE ocean bottom pressure anomalies", "ispublished": "pub", "full_text_status": "public", "keywords": "General Earth and Planetary Sciences; Geophysics", "note": "We thank Elanor Frajka-Williams for her helpful discussions about the RAPID-MOCHA measurements, and Don Chambers and an anonymous reviewer for their very constructive comments. This work represents one phase of research carried out at the Jet Propulsion Laboratory/California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The JPL-RL05M GRACE solutions are available via the Physical Oceanography Distributed Active Archive Center (PODAAC) as well as the GRACE Tellus websites (www.grace.jpl.nasa.gov). RAPID is funded by the Natural Environment Research Council in the UK and the National Science Foundation and National Oceanic and Atmospheric Administration in the United States. Data are freely available from http://www.rapid.ac.uk. \n\nThe Editor thanks Don Chambers and an anonymous reviewer for their assistance in evaluating this paper.\n\n", "abstract": "Concerns about North Atlantic Meridional Overturning Circulation (NAMOC) changes imply the need for a continuous, large-scale observation capability to detect changes on interannual to decadal time scales. Here we present the first measurements of Lower North Atlantic Deep Water (LNADW) transport changes using only time-variable gravity observations from Gravity Recovery and Climate Experiment (GRACE) satellites from 2003 until now. Improved monthly gravity field retrievals allow the detection of North Atlantic interannual bottom pressure anomalies and LNADW transport estimates that are in good agreement with those from the Rapid Climate Change-Meridional Overturning Circulation and Heatflux Array (RAPID/MOCHA). Concurrent with the observed AMOC transport anomalies from late 2009 through early 2010, GRACE measured ocean bottom pressures changes in the 3000\u20135000\u2009m deep western North Atlantic on the order of 20\u2009mm-H\u2082O (200\u2009Pa), implying a southward volume transport anomaly in that layer of approximately \u22125.5\u2009sverdrup. Our results highlight the efficacy of space gravimetry for observing AMOC variations to evaluate latitudinal coherency and long-term variability.", "date": "2015-10-16", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "42", "number": "19", "publisher": "American Geophysical Union", "pagerange": "8114-8121", "id_number": "CaltechAUTHORS:20230307-21989000.12", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21989000.12", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "Natural Environment Research Council (NERC)" }, { "agency": "NSF" }, { "agency": "National Oceanic and Atmospheric Administration (NOAA)" } ] }, "doi": "10.1002/2015gl065730", "primary_object": { "basename": "Geophysical_Research_Letters_-_2015_-_Landerer_-_North_Atlantic_meridional_overturning_circulation_variations_from_GRACE.pdf", "url": "https://authors.library.caltech.edu/records/dbvj5-dej19/files/Geophysical_Research_Letters_-_2015_-_Landerer_-_North_Atlantic_meridional_overturning_circulation_variations_from_GRACE.pdf" }, "resource_type": "article", "pub_year": "2015", "author_list": "Landerer, Felix W.; Wiese, David N.; et el." }, { "id": "https://authors.library.caltech.edu/records/dz4zn-9x315", "eprint_id": 119693, "eprint_status": "archive", "datestamp": "2023-08-22 15:52:03", "lastmod": "2023-10-25 16:44:56", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Park-Ryan-S", "name": { "family": "Park", "given": "Ryan S." }, "orcid": "0000-0001-9896-4585" }, { "id": "Bills-Bruce-G", "name": { "family": "Bills", "given": "Bruce" }, "orcid": "0000-0002-1978-8243" }, { "id": "Buffington-Brent-B", "name": { "family": "Buffington", "given": "Brent B." } }, { "id": "Folkner-William-M", "name": { "family": "Folkner", "given": "William M." }, "orcid": "0000-0001-5133-9934" }, { "id": "Konopliv-Alexander-S", "name": { "family": "Konopliv", "given": "Alexander S." }, "orcid": "0000-0001-8669-1866" }, { "id": "Martin-Mur-Tomas-J", "name": { "family": "Martin-Mur", "given": "Tomas J." } }, { "id": "Mastrodemos-Nickolaos", "name": { "family": "Mastrodemos", "given": "Nickolaos" } }, { "id": "McElrath-Timothy-P", "name": { "family": "McElrath", "given": "Timothy P." } }, { "id": "Riedel-Joseph-E", "name": { "family": "Riedel", "given": "Joseph E." } }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" } ] }, "title": "Improved detection of tides at Europa with radiometric and optical tracking during flybys", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Astronomy and Astrophysics", "note": "The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.", "abstract": "Due to its eccentric orbit about Jupiter, Europa experiences periodic tidal deformation, which causes changes in its gravitational field and induces both radial and transverse displacements of the surface. The amplitude and phase of these tidal changes are diagnostic of internal structure, and can be measured with sufficient radiometric and optical tracking of a spacecraft during a series of flyby encounters with Europa. This paper presents results of the simulated accuracy for recovery of the tides of Europa through measuring the second-degree tidal Love numbers k\u2082, h\u2082, and l\u2082. A reference trajectory, which consists of a total of 45 close flybys, was considered and a detailed covariance analysis was performed. The study was based on Earth-based Doppler tracking during \u00b12 h of each periapsis passage and surface imaging data taken below 500 km altitude. The result shows that the formal uncertainty of the second-degree tidal Love numbers can be estimated to be \u03c3_(k\u2082) = 0.01, \u03c3_(h\u2082) = 0.02, and \u03c3_(l\u2082) = 0.01, which is sufficient to constrain the global ice thickness to about 10 km under reasonable assumptions. Moreover, the forced librations of Europa can be measured to 0.3\u2033 accuracy, which can further constrain Europa's interior structure.", "date": "2015-07", "date_type": "published", "publication": "Planetary and Space Science", "volume": "112", "publisher": "Elsevier", "pagerange": "10-14", "id_number": "CaltechAUTHORS:20230307-21991000.13", "issn": "0032-0633", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21991000.13", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1016/j.pss.2015.04.005", "resource_type": "article", "pub_year": "2015", "author_list": "Park, Ryan S.; Bills, Bruce; et el." }, { "id": "https://authors.library.caltech.edu/records/6ym5h-2v305", "eprint_id": 119694, "eprint_status": "archive", "datestamp": "2023-08-22 15:18:19", "lastmod": "2023-10-23 20:01:39", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Wiese-David-N", "name": { "family": "Wiese", "given": "David N." }, "orcid": "0000-0001-7035-0514" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" }, { "id": "Boening-Carmen", "name": { "family": "Boening", "given": "Carmen" } }, { "id": "Landerer-Felix-W", "name": { "family": "Landerer", "given": "Felix W." }, "orcid": "0000-0003-2678-095X" } ] }, "title": "Improved methods for observing Earth's time variable mass distribution with GRACE using spherical cap mascons", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Earth and Planetary Sciences (miscellaneous); Geochemistry and Petrology; Geophysics", "note": "The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The JPL RL05 and RL05M solutions are available via the Physical Oceanography Distributed Active Archive Center (PODAAC) as well as the GRACE Tellus websites.\n\n", "abstract": "We discuss several classes of improvements to gravity solutions from the Gravity Recovery and Climate Experiment (GRACE) mission. These include both improvements in background geophysical models and orbital parameterization leading to the unconstrained spherical harmonic solution JPL RL05, and an alternate JPL RL05M mass concentration (mascon) solution benefitting from those same improvements but derived in surface spherical cap mascons. The mascon basis functions allow for convenient application of a priori information derived from near-global geophysical models to prevent striping in the solutions. The resulting mass flux solutions are shown to suffer less from leakage errors than harmonic solutions, and do not necessitate empirical filters to remove north-south stripes, lowering the dependence on using scale factors (the global mean scale factor decreases by 0.17) to gain accurate mass estimates. Ocean bottom pressure (OBP) time series derived from the mascon solutions are shown to have greater correlation with in situ data than do spherical harmonic solutions (increase in correlation coefficient of 0.08 globally), particularly in low-latitude regions with small signal power (increase in correlation coefficient of 0.35 regionally), in addition to reducing the error RMS with respect to the in situ data (reduction of 0.37 cm globally, and as much as 1 cm regionally). Greenland and Antarctica mass balance estimates derived from the mascon solutions agree within formal uncertainties with previously published results. Computing basin averages for hydrology applications shows general agreement between harmonic and mascon solutions for large basins; however, mascon solutions typically have greater resolution for smaller spatial regions, in particular when studying secular signals.", "date": "2015-04", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "120", "number": "4", "publisher": "American Geophysical Union", "pagerange": "2648-2671", "id_number": "CaltechAUTHORS:20230307-21998000.14", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-21998000.14", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1002/2014jb011547", "primary_object": { "basename": "JGR_Solid_Earth_-_2015_-_Watkins_-_Improved_methods_for_observing_Earth_s_time_variable_mass_distribution_with_GRACE_using.pdf", "url": "https://authors.library.caltech.edu/records/6ym5h-2v305/files/JGR_Solid_Earth_-_2015_-_Watkins_-_Improved_methods_for_observing_Earth_s_time_variable_mass_distribution_with_GRACE_using.pdf" }, "resource_type": "article", "pub_year": "2015", "author_list": "Watkins, Michael M.; Wiese, David N.; et el." }, { "id": "https://authors.library.caltech.edu/records/2vaje-qnn35", "eprint_id": 119695, "eprint_status": "archive", "datestamp": "2023-08-22 13:07:54", "lastmod": "2023-10-23 17:49:23", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Williams-James-G", "name": { "family": "Williams", "given": "James G." }, "orcid": "0000-0002-8441-5937" }, { "id": "Konopliv-Alexander-S", "name": { "family": "Konopliv", "given": "Alexander S." }, "orcid": "0000-0001-8669-1866" }, { "id": "Boggs-Dale-H", "name": { "family": "Boggs", "given": "Dale H." }, "orcid": "0000-0002-1568-3428" }, { "id": "Park-Ryan-S", "name": { "family": "Park", "given": "Ryan S." }, "orcid": "0000-0001-9896-4585" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" }, { "id": "Lemoine-Frank-G", "name": { "family": "Lemoine", "given": "Frank G." }, "orcid": "0000-0002-3051-1456" }, { "id": "Goosens-Sander", "name": { "family": "Goossens", "given": "Sander" } }, { "id": "Mazarico-Erwan", "name": { "family": "Mazarico", "given": "Erwan" }, "orcid": "0000-0003-3456-427X" }, { "id": "Nimmo-Francis", "name": { "family": "Nimmo", "given": "Francis" }, "orcid": "0000-0003-3573-5915" }, { "id": "Weber-Renee-C", "name": { "family": "Weber", "given": "Renee C." }, "orcid": "0000-0002-1649-483X" }, { "id": "Asmar-Sami-W", "name": { "family": "Asmar", "given": "Sami W." }, "orcid": "0000-0002-9912-645X" }, { "id": "Melosh-H-Jay", "name": { "family": "Melosh", "given": "H. Jay" }, "orcid": "0000-0003-1881-1496" }, { "id": "Neumann-Gregory-A", "name": { "family": "Neumann", "given": "Gregory A." }, "orcid": "0000-0003-0644-9944" }, { "id": "Phillips-Roger-J", "name": { "family": "Phillips", "given": "Roger J." }, "orcid": "0000-0001-5869-7427" }, { "id": "Smith-David-E", "name": { "family": "Smith", "given": "David E." } }, { "id": "Solomon-Sean-C", "name": { "family": "Solomon", "given": "Sean C." }, "orcid": "0000-0001-8328-7251" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Wieczorek-Mark-A", "name": { "family": "Wieczorek", "given": "Mark A." }, "orcid": "0000-0001-7007-4222" }, { "id": "Andrews-Hanna-Jeffrey-C", "name": { "family": "Andrews-Hanna", "given": "Jeffrey C." }, "orcid": "0000-0001-9374-7776" }, { "id": "Head-James-W-III", "name": { "family": "Head", "given": "James W." }, "orcid": "0000-0003-2013-560X" }, { "id": "Kiefer-Walter-S", "name": { "family": "Kiefer", "given": "Walter S." }, "orcid": "0000-0001-6741-5460" }, { "id": "Matsuyama-Isamu", "name": { "family": "Matsuyama", "given": "Isamu" }, "orcid": "0000-0002-2917-8633" }, { "id": "McGovern-Patrick-J", "name": { "family": "McGovern", "given": "Patrick J." }, "orcid": "0000-0001-9647-3096" }, { "id": "Taylor-G-Jeffrey", "name": { "family": "Taylor", "given": "G. Jeffrey" }, "orcid": "0000-0001-9471-3359" }, { "id": "Zuber-Maria-T", "name": { "family": "Zuber", "given": "Maria T." }, "orcid": "0000-0003-2652-8017" } ] }, "title": "Lunar interior properties from the GRAIL mission", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Earth and Planetary Sciences (miscellaneous); Geochemistry and Petrology; Geophysics", "note": "M. Efroimsky commented on tides and dissipation. K. Matsumoto and S.-C. Han provided information on their separate solutions. The GRAIL mission is a component of the NASA Discovery Program under contract to the Massachusetts Institute of Technology. The lunar laser ranging efforts at the McDonald Observatory, Observatoire de la C\u00f4te d'Azur, and Apache Point Observatory provided data that are archived by the International Laser Ranging Service at http://www.iers.org/IERS/EN/Organization/TechniqueCentres/ILRS/ilrs.html. A portion of the research described in this paper was carried out at the Jet Propulsion Laboratory of the California Institute of Technology, under a contract with the National Aeronautics and Space Administration.\n\nPublished - JGR_Planets_-_2014_-_Williams_-_Lunar_interior_properties_from_the_GRAIL_mission.pdf
", "abstract": "The Gravity Recovery and Interior Laboratory (GRAIL) mission has sampled lunar gravity with unprecedented accuracy and resolution. The lunar GM, the product of the gravitational constant G and the mass M, is very well determined. However, uncertainties in the mass and mean density, 3345.56\u2009\u00b1\u20090.40\u2009kg/m\u00b3, are limited by the accuracy of G. Values of the spherical harmonic degree-2 gravity coefficients J\u2082 and C\u2082\u2082, as well as the Love number k\u2082 describing lunar degree-2 elastic response to tidal forces, come from two independent analyses of the 3\u2009month GRAIL Primary Mission data at the Jet Propulsion Laboratory and the Goddard Space Flight Center. The two k\u2082 determinations, with uncertainties of ~1%, differ by 1%; the average value is 0.02416\u2009\u00b1\u20090.00022 at a 1\u2009month period with reference radius R\u2009=\u20091738\u2009km. Lunar laser ranging (LLR) data analysis determines (C\u2009\u2212\u2009A)/B and (B\u2009\u2212\u2009A)/C, where A\u2009<\u2009B\u2009<\u2009C are the principal moments of inertia; the flattening of the fluid outer core; the dissipation at its solid boundaries; and the monthly tidal dissipation Q\u2009=\u200937.5\u2009\u00b1\u20094. The moment of inertia computation combines the GRAIL-determined J\u2082 and C\u2082\u2082 with LLR-derived (C\u2009\u2212\u2009A)/B and (B\u2009\u2212\u2009A)/C. The normalized mean moment of inertia of the solid Moon is I\u209b/MR\u00b2\u2009=\u20090.392728\u2009\u00b1\u20090.000012. Matching the density, moment, and Love number, calculated models have a fluid outer core with radius of 200\u2013380\u2009km, a solid inner core with radius of 0\u2013280\u2009km and mass fraction of 0\u20131%, and a deep mantle zone of low seismic shear velocity. The mass fraction of the combined inner and outer core is \u22641.5%.", "date": "2014-07", "date_type": "published", "publication": "Journal of Geophysical Research. Planets", "volume": "119", "number": "7", "publisher": "American Geophysical Union", "pagerange": "1546-1578", "id_number": "CaltechAUTHORS:20230307-22002000.15", "issn": "2169-9097", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22002000.15", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1002/2013je004559", "primary_object": { "basename": "JGR_Planets_-_2014_-_Williams_-_Lunar_interior_properties_from_the_GRAIL_mission.pdf", "url": "https://authors.library.caltech.edu/records/2vaje-qnn35/files/JGR_Planets_-_2014_-_Williams_-_Lunar_interior_properties_from_the_GRAIL_mission.pdf" }, "resource_type": "article", "pub_year": "2014", "author_list": "Williams, James G.; Konopliv, Alexander S.; et el." }, { "id": "https://authors.library.caltech.edu/records/42ahb-y2f36", "eprint_id": 119696, "eprint_status": "archive", "datestamp": "2023-08-22 11:58:47", "lastmod": "2023-10-23 17:49:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Konopliv-Alexander-S", "name": { "family": "Konopliv", "given": "Alex S." }, "orcid": "0000-0001-8669-1866" }, { "id": "Park-Ryan-S", "name": { "family": "Park", "given": "Ryan S." }, "orcid": "0000-0001-9896-4585" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" }, { "id": "Asmar-Sami-W", "name": { "family": "Asmar", "given": "Sami W." }, "orcid": "0000-0002-9912-645X" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Williams-James-G", "name": { "family": "Williams", "given": "James G." }, "orcid": "0000-0002-8441-5937" }, { "id": "Fahnestock-Eugene", "name": { "family": "Fahnestock", "given": "Eugene" } }, { "id": "Kruizinga-Gerhard-L", "name": { "family": "Kruizinga", "given": "Gerhard" }, "orcid": "0000-0002-9301-4692" }, { "id": "Paik-Meegyeong", "name": { "family": "Paik", "given": "Meegyeong" }, "orcid": "0000-0002-3950-894X" }, { "id": "Strekalov-Dmitry-V", "name": { "family": "Strekalov", "given": "Dmitry" }, "orcid": "0000-0001-6058-7390" }, { "id": "Harvey-Nate", "name": { "family": "Harvey", "given": "Nate" } }, { "id": "Smith-David-E", "name": { "family": "Smith", "given": "David E." } }, { "id": "Zuber-Maria-T", "name": { "family": "Zuber", "given": "Maria T." }, "orcid": "0000-0003-2652-8017" } ] }, "title": "High-resolution lunar gravity fields from the GRAIL Primary and Extended Missions", "ispublished": "pub", "full_text_status": "public", "keywords": "General Earth and Planetary Sciences; Geophysics", "note": "The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We gratefully acknowledge the use of the Ames Pleiades Supercomputer that was used to generate the gravity solutions of this paper. We thank Mark Wieczorek for providing the equivalent gravity from topography harmonic field that is used in this paper. We appreciate Terry Sabaka directing us on the techniques of generating gravity errors using clone fields from the covariance matrix. Data used to generate the results of this paper are available at http://pds-geosciences.wustl.edu. \n\nThe Editor thanks two anonymous reviewers for their assistance in evaluating this paper.\n\n", "abstract": "The resolution and accuracy of the lunar spherical harmonic gravity field have been dramatically improved as a result of the Gravity Recovery and Interior Laboratory (GRAIL) mission. From the Primary Mission, previous harmonic gravity fields resulted in an average n\u2009=\u2009420 surface resolution and a Bouguer spectrum to n\u2009=\u2009330. The GRAIL Extended Mission improves the resolution due to a lower average 23 km altitude orbit. As a result, new harmonic degree 900 gravity fields (GL0900C and GL0900D) show nearly a factor of 2 improvement with an average surface resolution n\u2009=\u2009870 and the Bouguer spectrum extended to n\u2009=\u2009550. Since the minimum spacecraft altitude varies spatially between 3\u2009km and 23\u2009km, the surface resolution is variable from near n\u2009=\u2009680 for the central farside to near n\u2009=\u2009900 for the polar regions. These gravity fields with 0.8 million parameters are by far the highest-degree fields of any planet ever estimated with a fully dynamic least squares technique using spacecraft tracking data.", "date": "2014-03-16", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "41", "number": "5", "publisher": "American Geophysical Union", "pagerange": "1452-1458", "id_number": "CaltechAUTHORS:20230307-22017000.17", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22017000.17", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1002/2013gl059066", "primary_object": { "basename": "Geophysical_Research_Letters_-_2014_-_Konopliv_-_High\u2010resolution_lunar_gravity_fields_from_the_GRAIL_Primary_and_Extended.pdf", "url": "https://authors.library.caltech.edu/records/42ahb-y2f36/files/Geophysical_Research_Letters_-_2014_-_Konopliv_-_High\u2010resolution_lunar_gravity_fields_from_the_GRAIL_Primary_and_Extended.pdf" }, "resource_type": "article", "pub_year": "2014", "author_list": "Konopliv, Alex S.; Park, Ryan S.; et el." }, { "id": "https://authors.library.caltech.edu/records/bqr30-9s721", "eprint_id": 119698, "eprint_status": "archive", "datestamp": "2023-08-22 10:16:17", "lastmod": "2023-10-25 16:45:01", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zuber-Maria-T", "name": { "family": "Zuber", "given": "Maria T." }, "orcid": "0000-0003-2652-8017" }, { "id": "Smith-David-E", "name": { "family": "Smith", "given": "David E." } }, { "id": "Lehman-David-H", "name": { "family": "Lehman", "given": "David H." } }, { "id": "Hoffman-Tom-L", "name": { "family": "Hoffman", "given": "Tom L." } }, { "id": "Asmar-Sami-W", "name": { "family": "Asmar", "given": "Sami W." }, "orcid": "0000-0002-9912-645X" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" } ] }, "title": "Gravity Recovery and Interior Laboratory (GRAIL): Mapping the Lunar Interior from Crust to Core", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Astronomy and Astrophysics", "note": "The GRAIL mission is supported by NASA's Discovery Program and is performed under contract to the Massachusetts Institute of Technology. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.", "abstract": "The Gravity Recovery and Interior Laboratory (GRAIL) is a spacecraft-to-spacecraft tracking mission that was developed to map the structure of the lunar interior by producing a detailed map of the gravity field. The resulting model of the interior will be used to address outstanding questions regarding the Moon's thermal evolution, and will be applicable more generally to the evolution of all terrestrial planets. Each GRAIL orbiter contains a Lunar Gravity Ranging System instrument that conducts dual-one-way ranging measurements to measure precisely the relative motion between them, which in turn are used to develop the lunar gravity field map. Each orbiter also carries an Education/Public Outreach payload, Moon Knowledge Acquired by Middle-School Students (MoonKAM), in which middle school students target images of the Moon for subsequent classroom analysis. Subsequent to a successful launch on September 10, 2011, the twin GRAIL orbiters embarked on independent trajectories on a 3.5-month-long cruise to the Moon via the EL-1 Lagrange point. The spacecraft were inserted into polar orbits on December 31, 2011 and January 1, 2012. After a succession of 19 maneuvers the two orbiters settled into precision formation to begin science operations in March 1, 2012 with an average altitude of 55 km. The Primary Mission, which consisted of three 27.3-day mapping cycles, was successfully completed in June 2012. The extended mission will permit a second three-month mapping phase at an average altitude of 23 km. This paper provides an overview of the mission: science objectives and measurements, spacecraft and instruments, mission development and design, and data flow and data products.", "date": "2013-09", "date_type": "published", "publication": "Space Science Reviews", "volume": "178", "number": "1", "publisher": "Springer", "pagerange": "3-24", "id_number": "CaltechAUTHORS:20230307-22031000.20", "issn": "0038-6308", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22031000.20", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1007/s11214-012-9952-7", "resource_type": "article", "pub_year": "2013", "author_list": "Zuber, Maria T.; Smith, David E.; et el." }, { "id": "https://authors.library.caltech.edu/records/d49v5-att43", "eprint_id": 119697, "eprint_status": "archive", "datestamp": "2023-08-22 10:16:13", "lastmod": "2023-10-25 16:44:58", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Asmar-Sami-W", "name": { "family": "Asmar", "given": "Sami W." }, "orcid": "0000-0002-9912-645X" }, { "id": "Konopliv-Alexander-S", "name": { "family": "Konopliv", "given": "Alexander S." }, "orcid": "0000-0001-8669-1866" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Williams-James-G", "name": { "family": "Williams", "given": "James G." }, "orcid": "0000-0002-8441-5937" }, { "id": "Park-Ryan-S", "name": { "family": "Park", "given": "Ryan S." }, "orcid": "0000-0001-9896-4585" }, { "id": "Kruizinga-Gerhard-L", "name": { "family": "Kruizinga", "given": "Gerhard" }, "orcid": "0000-0002-9301-4692" }, { "id": "Paik-Meegyeong", "name": { "family": "Paik", "given": "Meegyeong" }, "orcid": "0000-0002-3950-894X" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" }, { "id": "Fahnestock-Eugene", "name": { "family": "Fahnestock", "given": "Eugene" } }, { "id": "Strekalov-Dmitry-V", "name": { "family": "Strekalov", "given": "Dmitry" }, "orcid": "0000-0001-6058-7390" }, { "id": "Harvey-Nate", "name": { "family": "Harvey", "given": "Nate" } }, { "id": "Lu-Wenwen", "name": { "family": "Lu", "given": "Wenwen" } }, { "id": "Kahan-Daniel", "name": { "family": "Kahan", "given": "Daniel" }, "orcid": "0000-0003-4211-536X" }, { "id": "Oudrhiri-Kamal", "name": { "family": "Oudrhiri", "given": "Kamal" } }, { "id": "Smith-David-E", "name": { "family": "Smith", "given": "David E." } }, { "id": "Zuber-Maria-T", "name": { "family": "Zuber", "given": "Maria T." }, "orcid": "0000-0003-2652-8017" } ] }, "title": "The Scientific Measurement System of the Gravity Recovery and Interior Laboratory (GRAIL) Mission", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Astronomy and Astrophysics", "note": "The GRAIL mission is supported by the NASA Discovery Program under contracts to the Massachusetts Institute of Technology and the Jet Propulsion Laboratory. The work described in this paper was mostly carried out at Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. The authors thank colleagues who have contributed to this work or reviewed it, especially at JPL: Duncan McPherson, Ralph Roncoli, William Folkner, Kevin Barltrop, Charles Dunn, William Klipstein, Randy Dodge, William Bertch, Daniel Klein, Dong Shin, Stefan Esterhausin, Slava Turyshev, Tom Hoffman, Charles Bell, Hoppy Price, Neil Dahya, Joseph Beerer, Glen Havens, Robert Gounley, Ruth Fragoso, Susan Kurtik, Behzad Raofi, and Dolan Highsmith. From Lockheed Martin Space Systems Company (Denver): Stu Spath, Tim Linn, Ryan Olds, Dave Eckart, and Brad Haack, Kevin Johnson, Carey Parish, Chris May, Rob Chambers, Kristian Waldorff, Josh Wood, Piet Kallemeyn, Angus McMechan, Cavan Cuddy, and Steve Odiorne. From the NASA Goddard Space Flight Center: Frank Lemoine and David Rowlands, and from the University of Texas: Byron Tapley and Srinivas Bettadpur.", "abstract": "The Gravity Recovery and Interior Laboratory (GRAIL) mission to the Moon utilized an integrated scientific measurement system comprised of flight, ground, mission, and data system elements in order to meet the end-to-end performance required to achieve its scientific objectives. Modeling and simulation efforts were carried out early in the mission that influenced and optimized the design, implementation, and testing of these elements. Because the two prime scientific observables, range between the two spacecraft and range rates between each spacecraft and ground stations, can be affected by the performance of any element of the mission, we treated every element as part of an extended science instrument, a science system. All simulations and modeling took into account the design and configuration of each element to compute the expected performance and error budgets. In the process, scientific requirements were converted to engineering specifications that became the primary drivers for development and testing. Extensive simulations demonstrated that the scientific objectives could in most cases be met with significant margin. Errors are grouped into dynamic or kinematic sources and the largest source of non-gravitational error comes from spacecraft thermal radiation. With all error models included, the baseline solution shows that estimation of the lunar gravity field is robust against both dynamic and kinematic errors and a nominal field of degree 300 or better could be achieved according to the scaled Kaula rule for the Moon. The core signature is more sensitive to modeling errors and can be recovered with a small margin.", "date": "2013-09", "date_type": "published", "publication": "Space Science Reviews", "volume": "178", "number": "1", "publisher": "Springer", "pagerange": "25-55", "id_number": "CaltechAUTHORS:20230307-22020000.18", "issn": "0038-6308", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22020000.18", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1007/s11214-013-9962-0", "resource_type": "article", "pub_year": "2013", "author_list": "Asmar, Sami W.; Konopliv, Alexander S.; et el." }, { "id": "https://authors.library.caltech.edu/records/vdhyj-f3q68", "eprint_id": 119699, "eprint_status": "archive", "datestamp": "2023-08-22 09:48:32", "lastmod": "2023-10-25 16:45:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Konopliv-Alexander-S", "name": { "family": "Konopliv", "given": "Alex S." }, "orcid": "0000-0001-8669-1866" }, { "id": "Park-Ryan-S", "name": { "family": "Park", "given": "Ryan S." }, "orcid": "0000-0001-9896-4585" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" }, { "id": "Asmar-Sami-W", "name": { "family": "Asmar", "given": "Sami W." }, "orcid": "0000-0002-9912-645X" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Williams-James-G", "name": { "family": "Williams", "given": "James G." }, "orcid": "0000-0002-8441-5937" }, { "id": "Fahnestock-Eugene", "name": { "family": "Fahnestock", "given": "Eugene" } }, { "id": "Kruizinga-Gerhard-L", "name": { "family": "Kruizinga", "given": "Gerhard" }, "orcid": "0000-0002-9301-4692" }, { "id": "Paik-Meegyeong", "name": { "family": "Paik", "given": "Meegyeong" }, "orcid": "0000-0002-3950-894X" }, { "id": "Strekalov-Dmitry-V", "name": { "family": "Strekalov", "given": "Dmitry" }, "orcid": "0000-0001-6058-7390" }, { "id": "Harvey-Nate", "name": { "family": "Harvey", "given": "Nate" } }, { "id": "Smith-David-E", "name": { "family": "Smith", "given": "David E." } }, { "id": "Zuber-Maria-T", "name": { "family": "Zuber", "given": "Maria T." }, "orcid": "0000-0003-2652-8017" } ] }, "title": "The JPL lunar gravity field to spherical harmonic degree 660 from the GRAIL Primary Mission", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Earth and Planetary Sciences (miscellaneous); Geochemistry and Petrology; Geophysics", "note": "The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We gratefully acknowledge the use of the Lonestar Texas Supercomputer used in the initial development of the GRAIL lunar gravity field and the Ames Pleiades Supercomputer that was used to generate the GL0660B gravity solution of this paper. We thank the GRAIL Navigation team (P. Antresian, M. Ryne, T. You) for many useful discussions and feedback on the GRAIL gravity fields, and for the Mission Design team (R. Roncoli, M. Wallace, S. Hatch, T. Sweetser) for accommodating many of the requests to optimize the gravity science. We thank K. Oudrhiri, D. Kahan, and D. Fleischman for their GRAIL Level-1 contributions, and W. Lu for earlier contributions to the GRAIL gravity effort.\n\n", "abstract": "The lunar gravity field and topography provide a way to probe the interior structure of the Moon. Prior to the Gravity Recovery and Interior Laboratory (GRAIL) mission, knowledge of the lunar gravity was limited mostly to the nearside of the Moon, since the farside was not directly observable from missions such as Lunar Prospector. The farside gravity was directly observed for the first time with the SELENE mission, but was limited to spherical harmonic degree n\u2009\u2264\u200970. The GRAIL Primary Mission, for which results are presented here, dramatically improves the gravity spectrum by up to ~4 orders of magnitude for the entire Moon and for more than 5 orders-of-magnitude over some spectral ranges by using interspacecraft measurements with near 0.03 \u03bcm/s accuracy. The resulting GL0660B (n\u2009=\u2009660) solution has 98% global coherence with topography to n\u2009=\u2009330, and has variable regional surface resolution between n\u2009=\u2009371 (14.6\u2009km) and n\u2009=\u2009583 (9.3\u2009km) because the gravity data were collected at different spacecraft altitudes. The GRAIL data also improve low-degree harmonics, and the uncertainty in the lunar Love number has been reduced by ~5\u00d7 to k\u2082\u2009=\u20090.02405\u2009\u00b1\u20090.00018. The reprocessing of the Lunar Prospector data indicates ~3\u00d7 improved orbit uncertainty for the lower altitudes to ~10 m, whereas the GRAIL orbits are determined to an accuracy of 20\u2009cm.", "date": "2013-07", "date_type": "published", "publication": "Journal of Geophysical Research. Planets", "volume": "118", "number": "7", "publisher": "American Geophysical Union", "pagerange": "1415-1434", "id_number": "CaltechAUTHORS:20230307-22036000.21", "issn": "2169-9097", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22036000.21", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1002/jgre.20097", "primary_object": { "basename": "JGR_Planets_-_2013_-_Konopliv_-_The_JPL_lunar_gravity_field_to_spherical_harmonic_degree_660_from_the_GRAIL_Primary_Mission.pdf", "url": "https://authors.library.caltech.edu/records/vdhyj-f3q68/files/JGR_Planets_-_2013_-_Konopliv_-_The_JPL_lunar_gravity_field_to_spherical_harmonic_degree_660_from_the_GRAIL_Primary_Mission.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Konopliv, Alex S.; Park, Ryan S.; et el." }, { "id": "https://authors.library.caltech.edu/records/grfn7-dsk82", "eprint_id": 119701, "eprint_status": "archive", "datestamp": "2023-08-22 08:41:02", "lastmod": "2023-10-25 16:45:08", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zuber-Maria-T", "name": { "family": "Zuber", "given": "Maria T." }, "orcid": "0000-0003-2652-8017" }, { "id": "Smith-David-E", "name": { "family": "Smith", "given": "David E." } }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." } }, { "id": "Asmar-Sami-W", "name": { "family": "Asmar", "given": "Sami W." }, "orcid": "0000-0002-9912-645X" }, { "id": "Konopliv-Alexander-S", "name": { "family": "Konopliv", "given": "Alexander S." }, "orcid": "0000-0001-8669-1866" }, { "id": "Lemoine-Frank-G", "name": { "family": "Lemoine", "given": "Frank G." }, "orcid": "0000-0002-3051-1456" }, { "id": "Melosh-H-Jay", "name": { "family": "Melosh", "given": "H. Jay" }, "orcid": "0000-0003-1881-1496" }, { "id": "Neumann-Gregory-A", "name": { "family": "Neumann", "given": "Gregory A." }, "orcid": "0000-0003-0644-9944" }, { "id": "Phillips-Roger-J", "name": { "family": "Phillips", "given": "Roger J." } }, { "id": "Solomon-Sean-C", "name": { "family": "Solomon", "given": "Sean C." }, "orcid": "0000-0001-8328-7251" }, { "id": "Wieczorek-Mark-A", "name": { "family": "Wieczorek", "given": "Mark A." }, "orcid": "0000-0001-7007-4222" }, { "id": "Williams-James-G", "name": { "family": "Williams", "given": "James G." } }, { "id": "Goosens-Sander-J", "name": { "family": "Goossens", "given": "Sander J." } }, { "id": "Kruizinga-Gerhard-L", "name": { "family": "Kruizinga", "given": "Gerhard" }, "orcid": "0000-0002-9301-4692" }, { "id": "Mazarico-Erwan", "name": { "family": "Mazarico", "given": "Erwan" }, "orcid": "0000-0003-3456-427X" }, { "id": "Park-Ryan-S", "name": { "family": "Park", "given": "Ryan S." }, "orcid": "0000-0001-9896-4585" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" } ] }, "title": "Gravity Field of the Moon from the Gravity Recovery and Interior Laboratory (GRAIL) Mission", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "note": "The GRAIL mission is supported by NASA's Discovery Program and is performed under contract to the Massachusetts Institute of Technology and the Jet Propulsion Laboratory, California Institute of Technology. We are grateful to the GRAIL spacecraft, instrument, and operations teams for outstanding support. We thank J. Andrews-Hanna, J. Head, W. Kiefer, P. McGovern, F. Nimmo, J. Soderblom, and M. Sori for helpful comments on the manuscript. The data used in this study have been submitted to the Geosciences Node of the NASA Planetary Data System.", "abstract": "Spacecraft-to-spacecraft tracking observations from the Gravity Recovery and Interior Laboratory (GRAIL) have been used to construct a gravitational field of the Moon to spherical harmonic degree and order 420. The GRAIL field reveals features not previously resolved, including tectonic structures, volcanic landforms, basin rings, crater central peaks, and numerous simple craters. From degrees 80 through 300, over 98% of the gravitational signature is associated with topography, a result that reflects the preservation of crater relief in highly fractured crust. The remaining 2% represents fine details of subsurface structure not previously resolved. GRAIL elucidates the role of impact bombardment in homogenizing the distribution of shallow density anomalies on terrestrial planetary bodies.", "date": "2013-02-08", "date_type": "published", "publication": "Science", "volume": "339", "number": "6120", "publisher": "American Association for the Advancement of Science", "pagerange": "668-671", "id_number": "CaltechAUTHORS:20230307-22082000.24", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22082000.24", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1126/science.1231507", "resource_type": "article", "pub_year": "2013", "author_list": "Zuber, Maria T.; Smith, David E.; et el." }, { "id": "https://authors.library.caltech.edu/records/t35vc-qa724", "eprint_id": 119700, "eprint_status": "archive", "datestamp": "2023-08-22 08:40:58", "lastmod": "2023-10-25 16:45:06", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wieczorek-Mark-A", "name": { "family": "Wieczorek", "given": "Mark A." }, "orcid": "0000-0001-7007-4222" }, { "id": "Neumann-Gregory-A", "name": { "family": "Neumann", "given": "Gregory A." }, "orcid": "0000-0003-0644-9944" }, { "id": "Nimmo-Francis", "name": { "family": "Nimmo", "given": "Francis" }, "orcid": "0000-0003-3573-5915" }, { "id": "Kiefer-Walter-S", "name": { "family": "Kiefer", "given": "Walter S." }, "orcid": "0000-0001-6741-5460" }, { "id": "Taylor-G-Jeffrey", "name": { "family": "Taylor", "given": "G. Jeffrey" } }, { "id": "Melosh-H-Jay", "name": { "family": "Melosh", "given": "H. Jay" }, "orcid": "0000-0003-1881-1496" }, { "id": "Phillips-Roger-J", "name": { "family": "Phillips", "given": "Roger J." } }, { "id": "Solomon-Sean-C", "name": { "family": "Solomon", "given": "Sean C." }, "orcid": "0000-0001-8328-7251" }, { "id": "Andrews-Hanna-Jeffrey-C", "name": { "family": "Andrews-Hanna", "given": "Jeffrey C." }, "orcid": "0000-0001-9374-7776" }, { "id": "Asmar-Sami-W", "name": { "family": "Asmar", "given": "Sami W." }, "orcid": "0000-0002-9912-645X" }, { "id": "Konopliv-Alexander-S", "name": { "family": "Konopliv", "given": "Alexander S." }, "orcid": "0000-0001-8669-1866" }, { "id": "Lemoine-Frank-G", "name": { "family": "Lemoine", "given": "Frank G." }, "orcid": "0000-0002-3051-1456" }, { "id": "Smith-David-E", "name": { "family": "Smith", "given": "David E." } }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Williams-James-G", "name": { "family": "Williams", "given": "James G." }, "orcid": "0000-0002-8441-5937" }, { "id": "Zuber-Maria-T", "name": { "family": "Zuber", "given": "Maria T." }, "orcid": "0000-0003-2652-8017" } ] }, "title": "The Crust of the Moon as Seen by GRAIL", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "note": "The GRAIL mission is supported by the Discovery Program of NASA and is performed under contract to the Massachusetts Institute of Technology and the Jet Propulsion Laboratory, California Institute of Technology. Additional support for this work was provided by the French Space Agency (CNES), the Centre National de la Recherche Scientifique, and the UnivEarthS LabEx project of Sorbonne Paris Cit\u00e9. Data products will be made available from the authors upon request.", "abstract": "High-resolution gravity data obtained from the dual Gravity Recovery and Interior Laboratory (GRAIL) spacecraft show that the bulk density of the Moon's highlands crust is 2550 kilograms per cubic meter, substantially lower than generally assumed. When combined with remote sensing and sample data, this density implies an average crustal porosity of 12% to depths of at least a few kilometers. Lateral variations in crustal porosity correlate with the largest impact basins, whereas lateral variations in crustal density correlate with crustal composition. The low-bulk crustal density allows construction of a global crustal thickness model that satisfies the Apollo seismic constraints, and with an average crustal thickness between 34 and 43 kilometers, the bulk refractory element composition of the Moon is not required to be enriched with respect to that of Earth.", "date": "2013-02-08", "date_type": "published", "publication": "Science", "volume": "339", "number": "6120", "publisher": "American Association for the Advancement of Science", "pagerange": "671-675", "id_number": "CaltechAUTHORS:20230307-22080000.23", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22080000.23", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "Centre National d'\u00c9tudes Spatiales (CNES)" }, { "agency": "Centre National de la Recherche Scientifique (CNRS)" }, { "agency": "Sorbonne Universit\u00e9" } ] }, "doi": "10.1126/science.1231530", "resource_type": "article", "pub_year": "2013", "author_list": "Wieczorek, Mark A.; Neumann, Gregory A.; et el." }, { "id": "https://authors.library.caltech.edu/records/00q6m-99j93", "eprint_id": 35374, "eprint_status": "archive", "datestamp": "2023-08-22 06:27:32", "lastmod": "2023-10-20 16:09:33", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Golombek-M", "name": { "family": "Golombek", "given": "M." } }, { "id": "Grant-J", "name": { "family": "Grant", "given": "J." } }, { "id": "Kipp-D", "name": { "family": "Kipp", "given": "D." } }, { "id": "Vasavada-A-R", "name": { "family": "Vasavada", "given": "A." }, "orcid": "0000-0003-2665-286X" }, { "id": "Kirk-R", "name": { "family": "Kirk", "given": "R." }, "orcid": "0000-0003-0842-9226" }, { "id": "Fergason-R", "name": { "family": "Fergason", "given": "R." }, "orcid": "0000-0002-2044-1714" }, { "id": "Bellutta-P", "name": { "family": "Bellutta", "given": "P." } }, { "id": "Calef-F", "name": { "family": "Calef", "given": "F." } }, { "id": "Larsen-K", "name": { "family": "Larsen", "given": "K." } }, { "id": "Katayama-Y", "name": { "family": "Katayama", "given": "Y." } }, { "id": "Huertas-A", "name": { "family": "Huertas", "given": "A." } }, { "id": "Beyer-R", "name": { "family": "Beyer", "given": "R." } }, { "id": "Chen-A", "name": { "family": "Chen", "given": "A." } }, { "id": "Parker-T", "name": { "family": "Parker", "given": "T." } }, { "id": "Pollard-B", "name": { "family": "Pollard", "given": "B." } }, { "id": "Lee-S", "name": { "family": "Lee", "given": "S." } }, { "id": "Sun-Y", "name": { "family": "Sun", "given": "Y." } }, { "id": "Hoover-R", "name": { "family": "Hoover", "given": "R." } }, { "id": "Sladek-H", "name": { "family": "Sladek", "given": "H." } }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "J." }, "orcid": "0000-0001-9324-1257" }, { "id": "Welch-R", "name": { "family": "Welch", "given": "R." } }, { "id": "Dobrea-E-N", "name": { "family": "Dobrea", "given": "E. Noe" } }, { "id": "Michalski-J", "name": { "family": "Michalski", "given": "J." } }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "M." } } ] }, "title": "Selection of the Mars Science Laboratory Landing Site", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Landing sites; Mars; Surface materials; Surface characteristics; Mars Science Laboratory", "note": "\u00a9 2012 Springer Science+Business Media B.V.\n\nReceived: 20 October 2011; Accepted: 25 June 2012; Published online: 21 July 2012.\n\nResearch described in this paper was partially done by the MSL project, Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration and was supported by the Mars Data Analysis Program. Derived data products were sponsored by the Critical Data Products program administered by the JPL Mars Exploration Program office. We especially thank members of the Council of Atmospheres and Council of Terrains for work on characterizing MSL landing sites. We thank L. Redmond and N. Warner for help with the figures.", "abstract": "The selection of Gale crater as the Mars Science Laboratory landing site took over five years, involved broad participation of the science community via five open workshops, and narrowed an initial >50 sites (25 by 20 km) to four finalists (Eberswalde, Gale, Holden and Mawrth) based on science and safety. Engineering constraints important to the selection included: (1) latitude (\u00b130\u00b0) for thermal management of the rover and instruments, (2) elevation (< \u22121 km) for sufficient atmosphere to slow the spacecraft, (3) relief of <100\u2013130 m at baselines of 1\u20131000 m for control authority and sufficient fuel during powered descent, (4) slopes of <30\u00b0 at baselines of 2\u20135 m for rover stability at touchdown, (5) moderate rock abundance to avoid impacting the belly pan during touchdown, and (6) a radar-reflective, load-bearing, and trafficable surface that is safe for landing and roving and not dominated\nby fine-grained dust. Science criteria important for the selection include the ability to assess past habitable environments, which include diversity, context, and biosignature (including organics) preservation. Sites were evaluated in detail using targeted data from instruments\non all active orbiters, and especially Mars Reconnaissance Orbiter. All of the final four sites have layered sedimentary rocks with spectral evidence for phyllosilicates that clearly address the science objectives of the mission. Sophisticated entry, descent and landing simulations that include detailed information on all of the engineering constraints indicate all of the final four sites are safe for landing. Evaluation of the traversabilty of the landing sites and target \"go to\" areas outside of the ellipse using slope and material properties information indicates that all are trafficable and \"go to\" sites can be accessed within the lifetime of the mission. In the final selection, Gale crater was favored over Eberswalde based on its greater diversity and potential habitability.", "date": "2012-09", "date_type": "published", "publication": "Space Science Reviews", "volume": "170", "number": "1-4", "publisher": "Springer", "pagerange": "641-737", "id_number": "CaltechAUTHORS:20121108-154625399", "issn": "0038-6308", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121108-154625399", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Mars Data Analysis Program" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/s11214-012-9916-y", "resource_type": "article", "pub_year": "2012", "author_list": "Golombek, M.; Grant, J.; et el." }, { "id": "https://authors.library.caltech.edu/records/cg2qw-zcd15", "eprint_id": 27240, "eprint_status": "archive", "datestamp": "2023-08-22 03:32:49", "lastmod": "2023-10-24 16:59:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Grant-John-A", "name": { "family": "Grant", "given": "John A." }, "orcid": "0000-0001-8276-1281" }, { "id": "Golombek-Matthew-P", "name": { "family": "Golombek", "given": "Matthew P." }, "orcid": "0000-0002-1928-2293" }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "John P." }, "orcid": "0000-0001-9324-1257" }, { "id": "Wilson-Sharon-A", "name": { "family": "Wilson", "given": "Sharon A." } }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." } }, { "id": "Vasavada-Ashwin-R", "name": { "family": "Vasavada", "given": "Ashwin R." }, "orcid": "0000-0003-2665-286X" }, { "id": "Griffes-Jennifer-L", "name": { "family": "Griffes", "given": "Jennifer L." } }, { "id": "Parker-Timothy-J", "name": { "family": "Parker", "given": "Timothy J." } } ] }, "title": "The science process for selecting the landing site for the 2011 Mars Science Laboratory", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Mars; Landing sites", "note": "\u00a9 2011 Elsevier.\n\nAvailable online 25 June 2010.\n\nReviews by Nicolas Mangold and an anonymous reviewer\nimproved the manuscript. Work supported by NASA MDAP Grant\nNNX09AI65G.", "abstract": "The process of identifying the landing site for NASA's 2011 Mars Science Laboratory (MSL) began in 2005 by defining science objectives, related to evaluating the potential habitability of a location on Mars, and engineering parameters, such as elevation, latitude, winds, and rock abundance, to determine acceptable surface and atmospheric characteristics. Nearly 60 candidate sites were considered at a series of open workshops in the years leading up to the launch. During that period, iteration between evolving engineering constraints and the relative science potential of candidate sites led to consensus on four final sites. The final site will be selected in the Spring of 2011 by NASA's Associate Administrator for the Science Mission Directorate. This paper serves as a record of landing site selection activities related primarily to science, an inventory of the number and variety of sites proposed, and a summary of the science potential of the highest ranking sites.", "date": "2011-09", "date_type": "published", "publication": "Planetary and Space Science", "volume": "59", "number": "11-12", "publisher": "Elsevier", "pagerange": "1114-1127", "id_number": "CaltechAUTHORS:20111014-150405516", "issn": "0032-0633", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111014-150405516", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NNX09AI65G" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.pss.2010.06.016", "resource_type": "article", "pub_year": "2011", "author_list": "Grant, John A.; Golombek, Matthew P.; et el." }, { "id": "https://authors.library.caltech.edu/records/6eby8-t4h41", "eprint_id": 119703, "eprint_status": "archive", "datestamp": "2023-08-22 02:03:54", "lastmod": "2023-10-23 16:11:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ivins-Erik-R", "name": { "family": "Ivins", "given": "Erik R." }, "orcid": "0000-0003-0148-357X" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Yuan-Dah-Ning", "name": { "family": "Yuan", "given": "Dah-Ning" }, "orcid": "0000-0001-9047-4063" }, { "id": "Dietrich-Reinhard", "name": { "family": "Dietrich", "given": "Reinhard" } }, { "id": "Casassa-Gino", "name": { "family": "Casassa", "given": "Gino" }, "orcid": "0000-0002-7888-071X" }, { "id": "R\u00fclke-Axel", "name": { "family": "R\u00fclke", "given": "Axel" }, "orcid": "0000-0003-1299-0163" } ] }, "title": "On-land ice loss and glacial isostatic adjustment at the Drake Passage: 2003\u20132009", "ispublished": "pub", "full_text_status": "public", "keywords": "Paleontology; Space and Planetary Science; Earth and Planetary Sciences (miscellaneous); Atmospheric Science; Earth-Surface Processes; Geochemistry and Petrology; Soil Science; Water Science and Technology; Ecology; Aquatic Science; Forestry; Oceanography; Geophysics", "note": "This research was supported by NASA's Earth Surface and Interior Focus Area as part of the GRACE Science Team effort and was performed at the Jet Propulsion Laboratory, California Institute of Technology. Parts of this research were supported by the International Bureau of the BMBF (Germany) and by the Chilean Government through the Millennium Science Initiative and the Centers of Excellence Base Financing Program of Conicyt which fund and the Centro de Estudios Cient\u00edficos (CECS). We thank Michael Bentley, David Bromwich, Ben Chao, Eugene Domack, Tom James, Matt King, Felix Landerer, Eric Rignot, Riccardo Riva, Christopher Shuman, Alexander Simms, Xiaoping Wu, and Victor Zlotnicki for their insight and helpful comments. Many of the figures in this paper were created using GMT open software [Wessel and Smith, 1995].\n\n", "abstract": "Land glacier extent and volume at the northern and southern margins of the Drake Passage have been in a state of dramatic demise since the early 1990s. Here time-varying space gravity observations from the Gravity Recovery and Climate Experiment (GRACE) are combined with Global Positioning System (GPS) bedrock uplift data to simultaneously solve for ice loss and for solid Earth glacial isostatic adjustment (GIA) to Little Ice Age (LIA) cryospheric loading. The present-day ice loss rates are determined to be \u221226 \u00b1 6 Gt/yr and \u221241.5 \u00b1 9 Gt/yr in the Southern and Northern Patagonia Ice Fields (NPI+SPI) and Antarctic Peninsula (AP), respectively. These are consistent with estimates based upon thickness and flux changes. Bounds are recovered for elastic lithosphere thicknesses of 35 \u2264 h \u2264 70 km and 20 \u2264 h \u2264 45 km and for upper mantle viscosities of 4\u20138 \u00d7 10\u00b9\u2078 Pa s and 3\u201310 \u00d7 10\u00b9\u2079 Pa s (using a half-space approximation) for NPI+SPI and AP, respectively, using an iterative forward model strategy. Antarctic Peninsula ice models with a prolonged LIA, extending to A.D. 1930, are favored in all \u03c7\u00b2 fits to the GPS uplift data. This result is largely decoupled from Earth structure assumptions. The GIA corrections account for roughly 20\u201360% of the space-determined secular gravity change. Collectively, the on-land ice losses correspond to volume increases of the oceans equivalent to 0.19 \u00b1 0.045 mm/yr of sea level rise for the last 15 years.", "date": "2011-02-07", "date_type": "published", "publication": "Journal of Geophysical Research D", "volume": "116", "number": "B2", "publisher": "American Geophysical Union", "pagerange": "Art. No. B02403", "id_number": "CaltechAUTHORS:20230307-22142000.27", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22142000.27", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "Bundesministerium f\u00fcr Bildung und Forschung (BMBF)" }, { "agency": "Millennium Science Initiative" } ] }, "doi": "10.1029/2010jb007607", "primary_object": { "basename": "Journal_of_Geophysical_Research__Solid_Earth_-_2011_-_Ivins_-_On\u2010land_ice_loss_and_glacial_isostatic_adjustment_at_the.pdf", "url": "https://authors.library.caltech.edu/records/6eby8-t4h41/files/Journal_of_Geophysical_Research__Solid_Earth_-_2011_-_Ivins_-_On\u2010land_ice_loss_and_glacial_isostatic_adjustment_at_the.pdf" }, "resource_type": "article", "pub_year": "2011", "author_list": "Ivins, Erik R.; Watkins, Michael M.; et el." }, { "id": "https://authors.library.caltech.edu/records/mh1h4-yy078", "eprint_id": 52043, "eprint_status": "archive", "datestamp": "2023-08-19 13:58:16", "lastmod": "2023-10-18 19:30:07", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tapley-B-D", "name": { "family": "Tapley", "given": "Byron D." } }, { "id": "Bettadpur-S", "name": { "family": "Bettadpur", "given": "Srinivas" } }, { "id": "Ries-J-C", "name": { "family": "Ries", "given": "John C." } }, { "id": "Thompson-P-F", "name": { "family": "Thompson", "given": "Paul F." } }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." } } ] }, "title": "GRACE Measurements of Mass Variability in the Earth System", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2004 American Association for the Advancement of Science.\n\nReceived 15 April2004; accepted 18 June 2004.\n\nWe thank M. Rodellfor providing terrestrial water\nstorage output from the GLDAS model, T. Pekker\nand J. Chen for conversion of the GLDAS output\ninto geopotential coefficients, and W. Bertiger, F.\nFlechtner, B. Gunter, Z. Kang, G. Kruizinga, P. Nagel,\nR. Pastor, S. Poole, L. Romans, H.-J. Rim, S.-C.\nWu, S. Yoon, and D.-N. Yuan for their vital contributions\nto the software development, algorithm\ntesting, and data processing required to accomplish\nthese results. Supported by NASA contract\nNAS5-97213.\n\nSupplemental Material - Tapley.SOM.pdf
", "abstract": "Monthly gravity field estimates made by the twin Gravity Recovery and Climate Experiment (GRACE) satellites have a geoid height accuracy of 2 to 3 millimeters at a spatial resolution as small as 400 kilometers. The annual cycle in the geoid variations, up to 10 millimeters in some regions, peaked predominantly in the spring and fall seasons. Geoid variations observed over South America that can be largely attributed to surface water and groundwater changes show a clear separation between the large Amazon watershed and the smaller watersheds to the north. Such observations will help hydrologists to connect processes at traditional length scales (tens of kilometers or less) to those at regional and global scales.", "date": "2004-07-23", "date_type": "published", "publication": "Science", "volume": "305", "number": "5683", "publisher": "American Association for the Advancement of Science", "pagerange": "503-505", "id_number": "CaltechAUTHORS:20141121-105248542", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141121-105248542", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NAS5-97213" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.1099192", "primary_object": { "basename": "Tapley.SOM.pdf", "url": "https://authors.library.caltech.edu/records/mh1h4-yy078/files/Tapley.SOM.pdf" }, "resource_type": "article", "pub_year": "2004", "author_list": "Tapley, Byron D.; Bettadpur, Srinivas; et el." }, { "id": "https://authors.library.caltech.edu/records/903bw-ma922", "eprint_id": 119704, "eprint_status": "archive", "datestamp": "2023-08-22 02:08:36", "lastmod": "2023-10-25 16:45:11", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yoon-Yoke-T", "name": { "family": "Yoon", "given": "Yoke T." } }, { "id": "Nerem-R-Steven", "name": { "family": "Nerem", "given": "Steven R." }, "orcid": "0000-0003-4064-8111" }, { "id": "Watkins-M-M", "name": { "family": "Watkins", "given": "Michael M." }, "orcid": "0000-0001-7524-4833" }, { "id": "Haines-Bruce-J", "name": { "family": "Haines", "given": "Bruce J." } }, { "id": "Kruizinga-Gerhard-L", "name": { "family": "Kruizinga", "given": "Gerhard L." }, "orcid": "0000-0002-9301-4692" } ] }, "title": "The Effects of GPS Carrier Phase Ambiguity Resolution on Jason-1", "ispublished": "pub", "full_text_status": "public", "keywords": "Oceanography", "note": "The author would like to thank the Orbiter and Radiometric Systems, and Satellite Geodesy and Geodynamics Systems groups at NASA Jet Propulsion Laboratory for their support and guidance in this study. Special thanks to Shailen Desai for providing JPL's reduced-dynamic orbit solutions, Da Kuang for assisting in the POD processing, and Yoaz Bar-Sever for providing the resources that make ambiguity resolution possible for Jason-1. The author is also grateful to John Ries at the University of Texas at Austin for providing the SLR/DORIS orbit solutions. A portion of this work was conducted at the Jet Propulsion Laboratory/California Institute of Technology in Pasadena, California. This work was supported by a NASA-funded Jason Science Investigation (PI: M. M. Watkins).", "abstract": "We have used GPS carrier phase integer ambiguity resolution to investigate improvements in the orbit determination for the Jason-1 satellite altimeter mission. The technique has been implemented in the GIPSY orbit determination software developed by JPL. The radial accuracy of the Jason-1 orbits is already near 1 cm, and thus it is difficult to detect the improvements gained when the carrier phase ambiguities are resolved. Nevertheless, each of the metrics we use to evaluate the orbit accuracy (orbit overlaps, orbit comparisons, satellite laser ranging residuals, altimeter crossover residuals, orbit centering) show modest improvement when the ambiguities are resolved. We conservatively estimate the improvement in the radial orbit accuracy is at the 10\u201320% level.", "date": "2004-07", "date_type": "published", "publication": "Marine Geodesy", "volume": "27", "number": "3-4", "publisher": "Informa UK Limited", "pagerange": "773-787", "id_number": "CaltechAUTHORS:20230307-22147000.29", "issn": "0149-0419", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-22147000.29", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1080/01490410490889058", "resource_type": "article", "pub_year": "2004", "author_list": "Yoon, Yoke T.; Nerem, Steven R.; et el." } ]