edu.ucar.opensky::articles:20986 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T02:27:33.417135 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7gt5qp9 https://doi.org/10.14291/tccon.ggg2014.lamont01.R1/1255070 https Related Dataset #1 TCCON data from Lamont (US), Release GGG2014.R1 https://doi.org/10.14291/tccon.ggg2014.orleans01.R0/1149276 https Related Dataset #2 TCCON data from Orléans (FR), Release GGG2014.R0 Observational evidence of 3-D cloud effects in OCO-2 CO2 retrievals 2017-07-11T00:00:00Z publication https://n2t.org/ark:/85065/d7gt5qp9 https://doi.org/10.1002/2016JD026111 Massie, Steven T. author Sebastian Schmidt, K. author Eldering, A. author Crisp, D. author UCAR/NCAR - Library publisher The standard deviations of the distributions of Orbiting Carbon Observatory (OCO-2) measurements of CO2 (i. e., XCO2) increase in size in the presence of clouds. XCO2 and Moderate Resolution Imaging Spectroradiometer (MODIS) radiance and cloud fields, and OCO-2 A-band radiances, are analyzed in order to determine if this behavior is best described as a radiance-level retrieval artifact or by 3-D radiative transfer effects. Observations in clear-sky and fair weather cumulus scenes are analyzed. Scatter diagrams of XCO2 versus MODIS (and OCO-2) radiances are presented, and averages are calculated for each scene for several radiance bins. The averages vary little in clear skies but decrease markedly for cloudy scenes as radiances increase. These decreases are consistent with an interpretative framework provided by 3-D SHDOM radiative transfer calculations. Two 3-D metrics,.XCO2 and Have, are calculated and applied..XCO2 is the difference in XCO2 for the smallest and largest radiance bins. Have is a measure of the heterogeneity of the cloud radiance field. Lines of XCO2 and MODIS radiance for four target mode scenes have different slopes for clear and cloudy scenes, contrary to the radiance-level retrieval artifact interpretation. In contrast, the graph of.XCO2 and MODIS Have for the various scenes has a linear correlation coefficient of 0.92, consistent with the 3-D interpretation. Since the OCO-2 measurement requirement is 1 ppmv, the cloudy scene XCO2 standard deviations between 1.2 and 2.6 ppmv indicate that 3-D cloud effects add an important component to the XCO2 error budget. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2017 American Geophysical Union. None eng geoscientificInformation