[ { "id": "authors:rxxxc-y3k98", "collection": "authors", "collection_id": "rxxxc-y3k98", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180927-072705334", "type": "article", "title": "Large regional shortwave forcing by anthropogenic methane informed by Jovian observations", "author": [ { "family_name": "Collins", "given_name": "William D.", "clpid": "Collins-W-D" }, { "family_name": "Feldman", "given_name": "Daniel R.", "clpid": "Feldman-D-R" }, { "family_name": "Kuo", "given_name": "Chaincy", "clpid": "Kuo-Chaincy" }, { "family_name": "Nguyen", "given_name": "Newton H.", "orcid": "0000-0002-9118-8672", "clpid": "Nguyen-Newton-H" } ], "abstract": "Recently, it was recognized that widely used calculations of methane radiative forcing systematically underestimated its global value by 15% by omitting its shortwave effects. We show that shortwave forcing by methane can be accurately calculated despite considerable uncertainty and large gaps in its shortwave spectroscopy. We demonstrate that the forcing is insensitive, even when confronted with much more complete methane absorption spectra extending to violet light wavelengths derived from observations of methane-rich Jovian planets. We undertake the first spatially resolved global calculations of this forcing and find that it is dependent on bright surface features and clouds. Localized annual mean forcing from preindustrial to present-day methane increases approaches +0.25 W/m^2, 10 times the global annualized shortwave forcing and 43% of the total direct CH_4 forcing. Shortwave forcing by anthropogenic methane is sufficiently large and accurate to warrant its inclusion in historical analyses, projections, and mitigation strategies for climate change.", "doi": "10.1126/sciadv.aas9593", "pmcid": "PMC6157968", "issn": "2375-2548", "publisher": "American Association for the Advancement of Science", "publication": "Science Advances", "publication_date": "2018-09", "series_number": "9", "volume": "4", "issue": "9", "pages": "Art. No. eaas9593" }, { "id": "authors:bdqk4-djd66", "collection": "authors", "collection_id": "bdqk4-djd66", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:FELjgrd08b", "type": "article", "title": "Remote sensing of tropical tropopause layer radiation balance using A-train measurements", "author": [ { "family_name": "Feldman", "given_name": "D. R.", "clpid": "Feldman-D-R" }, { "family_name": "L'Ecuyer", "given_name": "T. S.", "clpid": "L'Ecuyer-T-S" }, { "family_name": "Liou", "given_name": "K. N.", "clpid": "Liou-K-N" }, { "family_name": "Yung", "given_name": "Y. L.", "orcid": "0000-0002-4263-2562", "clpid": "Yung-Y-L" } ], "abstract": "Determining the level of zero net radiative heating (LZH) is critical to understanding parcel trajectory in the Tropical Tropopause Layer (TTL) and associated stratospheric hydration processes. Previous studies of the TTL radiative balance have focused on using radiosonde data, but remote sensing measurements from polar-orbiting satellites may provide the relevant horizontal and vertical information for assessing TTL solar heating and infrared cooling rates, especially across the Pacific Ocean. CloudSat provides a considerable amount of vertical information about the distribution of cloud properties relevant to heating rate analysis. The ability of CloudSat measurements and ancillary information to constrain LZH is explored. We employ formal error propagation analysis for derived heating rate uncertainty given the CloudSat cloud property retrieval algorithms. Estimation of the LZH to within approximately 0.5 to 1 km is achievable with CloudSat, but it has a low-altitude bias because the radar is unable to detect thin cirrus. This can be remedied with the proper utilization of Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) lidar backscatter information. By utilizing an orbital simulation with the GISS data set, we explore the representativeness of non-cross-track scanning active sounders in terms of describing the LZH distribution. In order to supplement CloudSat, we explore the ability of Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Scanning Radiometer-EOS (AMSR-E) to constrain LZH and find that these passive sounders are useful where the cloud top height does not exceed 7 km. The spatiotemporal distributions of LZH derived from CloudSat and CALIPSO measurements are presented which suggest that thin cirrus have a limited effect on LZH mean values but affect LZH variability.", "doi": "10.1029/2008JD010158", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research D", "publication_date": "2008-11-12", "series_number": "D21", "volume": "113", "issue": "D21", "pages": "D21113" }, { "id": "authors:w52xj-y5z18", "collection": "authors", "collection_id": "w52xj-y5z18", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180802-154731093", "type": "book_section", "title": "Using All Sky Cameras to determine cloud statistics for the Thirty Meter Telescope candidate sites", "book_title": "Ground-based and Airborne Telescopes II", "author": [ { "family_name": "Skidmore", "given_name": "Warren", "clpid": "Skidmore-W" }, { "family_name": "Sch\u00f6ck", "given_name": "Matthias", "clpid": "Sch\u00f6ck-M" }, { "family_name": "Magnier", "given_name": "Eugene", "orcid": "0000-0002-7965-2815", "clpid": "Magnier-E-A" }, { "family_name": "Walker", "given_name": "David", "clpid": "Walker-D-W" }, { "family_name": "Feldman", "given_name": "Dan", "clpid": "Feldman-D-R" }, { "family_name": "Riddle", "given_name": "Reed", "orcid": "0000-0002-0387-370X", "clpid": "Riddle-R-L" }, { "family_name": "Els", "given_name": "Sebastian", "clpid": "Els-S" }, { "family_name": "Travouillon", "given_name": "Tony", "clpid": "Travouillon-T" }, { "family_name": "Bustos", "given_name": "Edison", "clpid": "Bustos-E" }, { "family_name": "Seguel", "given_name": "Juan", "clpid": "Seguel-J" }, { "family_name": "Vasquez", "given_name": "Joselino", "clpid": "Vasquez-J" }, { "family_name": "Blum", "given_name": "Robert", "clpid": "Blum-R-D" }, { "family_name": "Gillett", "given_name": "Paul", "clpid": "Gillett-P" }, { "family_name": "Gregory", "given_name": "Brooke", "clpid": "Gregory-B" } ], "contributor": [ { "family_name": "Stepp", "given_name": "Larry M.", "clpid": "Stepp-L-M" }, { "family_name": "Gilmozzi", "given_name": "Roberto", "clpid": "Gilmozzi-R" } ], "abstract": "All Sky Cameras were deployed at all Thirty Meter Telescope (TMT) candidate sites. The images gathered by these cameras were used to assess the cloud statistics for each site. We describe two methods that were developed to do this, a manual method based on inspection of blue and red movies, and an automated method based on photometric analysis of the images.", "doi": "10.1117/12.788141", "isbn": "9780819472229", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_publication": "Bellingham, WA", "publication_date": "2008-07-10", "pages": "Art. No. 701224" }, { "id": "authors:ragg2-qsc56", "collection": "authors", "collection_id": "ragg2-qsc56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:FELjgrd08a", "type": "article", "title": "On the information content of the thermal infrared cooling rate profile from satellite instrument measurements", "author": [ { "family_name": "Feldman", "given_name": "D. R.", "clpid": "Feldman-D-R" }, { "family_name": "Liou", "given_name": "K. N.", "clpid": "Liou-K-N" }, { "family_name": "Shia", "given_name": "R. L.", "clpid": "Shia-R-L" }, { "family_name": "Yung", "given_name": "Y. L.", "orcid": "0000-0002-4263-2562", "clpid": "Yung-Y-L" } ], "abstract": "This work investigates how remote sensing of the quantities required to calculate clear-sky cooling rate profiles propagates into cooling rate profile knowledge. The formulation of a cooling rate profile error budget is presented for clear-sky scenes given temperature, water vapor, and ozone profile uncertainty. Using linear propagation of error analysis, an expression for the cooling rate profile covariance matrix is given. Some of the features of the cooling rate covariance matrix are discussed, and it is found that nonzero error correlations in the temperature, water vapor, and ozone retrieval profiles must be considered to produce an unbiased estimate of cooling rate profile variance and the covariance structure. To that end, the exclusion of the details of this error correlation leads to an underestimation of the cooling rate profile uncertainty. This work then examines the assumptions made in the course of deriving the expression for the cooling rate covariance matrix by using ERA-40 Reanalysis data. It is established that the assumptions of linear error propagation and Gaussian statistics are generally tenable. Next, the information content of thermal infrared spectra with respect to clear-sky cooling rate profiles is investigated. Several formerly- and currently-operational spectrometers are compared with different spectral coverage, resolution, signal-to-noise ratio. Among these, IASI is found to have the ability to provide the greatest amount of information on the cooling rate profile. Also, it may be scientifically useful to develop far-infrared missions in terms of cooling rate profile analysis.", "doi": "10.1029/2007JD009041", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research D", "publication_date": "2008-06-13", "volume": "113", "pages": "D11118" }, { "id": "authors:bmf4y-fen65", "collection": "authors", "collection_id": "bmf4y-fen65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140826-090755061", "type": "article", "title": "Retrieval of ozone profile from ground-based measurements with polarization: A synthetic study", "author": [ { "family_name": "Guo", "given_name": "Xin", "clpid": "Guo-Xin" }, { "family_name": "Natraj", "given_name": "Vijay", "orcid": "0000-0003-3154-9429", "clpid": "Natraj-V" }, { "family_name": "Feldman", "given_name": "Daniel R.", "clpid": "Feldman-D-R" }, { "family_name": "Spurr", "given_name": "Robert J. D.", "clpid": "Spurr-R-J-D" }, { "family_name": "Shia", "given_name": "Run-Lie", "orcid": "0000-0003-1911-3120", "clpid": "Shia-Run-Lie" }, { "family_name": "Sander", "given_name": "Stanley P.", "orcid": "0000-0003-1424-3620", "clpid": "Sander-S-P" }, { "family_name": "Yung", "given_name": "Yuk L.", "orcid": "0000-0002-4263-2562", "clpid": "Yung-Y-L" } ], "abstract": "We perform a retrieval based on optimal estimation theory to retrieve the vertical distribution of ozone from simulated spectra in the Huggins bands. The model atmosphere includes scattering by aerosol as well as Rayleigh scattering. The virtual instrument is ground-based and zenith-viewing. Using this algorithm, we show that it is possible to retrieve the ozone profile provided that the spectral resolution is at least 0.2 nm and the signal to noise ratio greater than 500. Our synthetic retrievals suggest that if we are able to measure the Stokes parameters Q, U and V with accuracy comparable to that of the intensity, the information contained in the measurements, and therefore the inversion, will improve. Furthermore, we find that the measurement of the full Stokes vector from the ground-based instrument will especially enhance the retrieval of tropospheric ozone. Utilizing concepts from information theory, our arguments are confirmed by increases in the degrees of freedom and the Shannon information content in the simulated measurements.", "doi": "10.1016/j.jqsrt.2006.05.008", "issn": "0022-4073", "publisher": "Elsevier", "publication": "Journal of Quantitative Spectroscopy and Radiative Transfer", "publication_date": "2007-01", "series_number": "1", "volume": "103", "issue": "1", "pages": "175-192" }, { "id": "authors:202pe-y5531", "collection": "authors", "collection_id": "202pe-y5531", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140821-153537924", "type": "article", "title": "Direct retrieval of stratospheric CO_2 infrared cooling rate profiles from AIRS data", "author": [ { "family_name": "Feldman", "given_name": "D. R.", "clpid": "Feldman-D-R" }, { "family_name": "Liou", "given_name": "K. N.", "clpid": "Liou-K-N" }, { "family_name": "Yung", "given_name": "Yuk L.", "orcid": "0000-0002-4263-2562", "clpid": "Yung-Y-L" }, { "family_name": "Tobin", "given_name": "D. C.", "clpid": "Tobin-D-C" }, { "family_name": "Berk", "given_name": "A.", "clpid": "Berk-A" } ], "abstract": "We expand upon methods for retrieving thermal infrared cooling rate profiles, originally developed by Liou and Xue (1988) through application to the inversion of the stratospheric cooling rate produced by carbon dioxide (CO_2) and a formal description of the associated error budget. Specifically, we infer lower- and mid-stratospheric cooling rates from the CO_2 \u03bd_2 band on the basis of selected spectral channels and available data from the Atmospheric Infrared Sounder (AIRS). In order to establish the validity of our results, we compare our retrievals to those calculated from a forward radiative transfer program using retrieved temperature data from spectra taken by the Scanning High-Resolution Interferometer Sounder (S-HIS) on two aircraft campaigns: the Mixed-Phase Arctic Cloud Experiment (MPACE) and the Aura Validation Experiment (AVE) both in Fall, 2004. Reasonable and consistent comparisons are illustrated, revealing that spectral radiance data taken by high-resolution infrared sounders can be used to determine the vertical distribution of radiative cooling due to CO_2.", "doi": "10.1029/2005GL024680", "issn": "0094-8276", "publisher": "American Geophysical Union", "publication": "Geophysical Research Letters", "publication_date": "2006-06-01", "series_number": "11", "volume": "33", "issue": "11", "pages": "Art. No. L11803" } ]