Toward improved satellite estimates of short‐wave radiative fluxes—Focus on cloud detection over snow: 1. Methodology

[1] A Coupled Cloud and Snow Detection Algorithm (CCSDA) for improving satellite capabilities to estimate downward surface short-wave radiation under snow conditions has been developed and will be described here. Four channels of the GOES-8 imager are used to detect clouds, snow, and to perform background analysis for each hour of the diurnal cycle. The Clear-Sky Background Analysis (CSBA) is used as a reference state to generate dynamic and location-dependent thresholds for cloud detection tests, and the CSBA of the visible channel is used as a required input for the solar radiation model. The implementation of any one component requires a priori information on the other two. Therefore the three components are coupled to iteratively update cloud detection variables, cloud amount, and snow cover. Snow detection aims to distinguish between snow-covered and snow-free pixels after a pixel is classified as clear. The CCSDA algorithm will be described, and preliminary evaluation of the impact of the improvements on surface radiative flux estimates will be presented in part 2 (Pinker et al., 2007).

[1]  Andrew G. Klein,et al.  Validation of daily MODIS snow cover maps of the Upper Rio Grande River Basin for the 2000–2001 snow year , 2003 .

[2]  William B. Rossow,et al.  Validation of ISCCP Cloud Detections , 1993 .

[3]  S. Hollinger,et al.  Illinois Climate Network: Site descriptions, instrumentation, and data management , 1994 .

[4]  W. Rossow,et al.  Cloud Detection Using Satellite Measurements of Infrared and Visible Radiances for ISCCP , 1993 .

[5]  Mary Jo Brodzik,et al.  Recent northern hemisphere snow extent: A comparison of data derived from visible and microwave satellite sensors , 2001 .

[6]  A. Ohmura,et al.  First global WCRP shortwave surface radiation budget dataset , 1995 .

[7]  B. McArthur,et al.  Baseline surface radiation network (BSRN/WCRP) New precision radiometry for climate research , 1998 .

[8]  G. P. Cressman.  AN OPERATIONAL OBJECTIVE ANALYSIS SYSTEM , 1959 .

[9]  Andrew G. Klein,et al.  Development of a technique to assess snow-cover mapping errors from space , 2001, IEEE Trans. Geosci. Remote. Sens..

[10]  W. Menzel,et al.  Discriminating clear sky from clouds with MODIS , 1998 .

[11]  William B. Rossow,et al.  Normalization and calibration of geostationary satellite radiances for the International Satellite Cloud Climatology Project , 1993 .

[12]  Rachel T. Pinker,et al.  Evaluation of Surface Shortwave Flux Estimates from GOES: Sensitivity to Sensor Calibration , 2006 .

[13]  C. Rao,et al.  Post-launch calibration of meteorological satellite sensors , 1999 .

[14]  N. DiGirolamo,et al.  MODIS snow-cover products , 2002 .

[15]  William B. Rossow,et al.  Update of Radiance Calibrations for ISCCP , 1997 .

[16]  J. D. Tarpley,et al.  Validation of the North American Land Data Assimilation System (NLDAS) retrospective forcing over the southern Great Plains : GEWEX Continental-Scale International Project, Part 3 (GCIP3) , 2003 .

[17]  Geneviève Sèze,et al.  Time-cumulated visible and infrared radiance histograms used as descriptors of surface and cloud variations , 1991 .

[18]  P. Romanov,et al.  Automated monitoring of snow cover over South America using GOES Imager data , 2003 .

[19]  P. Minnis,et al.  Rapid Calibration of Operational and Research Meteorological Satellite Imagers. Part I: Evaluation of Research Satellite Visible Channels as References , 2002 .

[20]  Martin Wild,et al.  A new snow cover fraction parametrization for the ECHAM4 GCM , 2001 .

[21]  J. D. Tarpley,et al.  Surface radiation budgets in support of the GEWEX Continental‐Scale International Project (GCIP) and the GEWEX Americas Prediction Project (GAPP), including the North American Land Data Assimilation System (NLDAS) project , 2003 .

[22]  K. Elder,et al.  Scale effects in a distributed snow water equivalence and snowmelt model for mountain basins , 1998 .

[23]  C Smith,et al.  Operational calibration of Geostationary Operational Environmental Satellite-8 and-9 imagers and sounders. , 1997, Applied optics.

[24]  J. D. Tarpley,et al.  Real‐time and retrospective forcing in the North American Land Data Assimilation System (NLDAS) project , 2003 .

[25]  David Robinson,et al.  Gridded North American monthly snow depth and snow water equivalent for GCM evaluation , 2003 .

[26]  Peter Romanov,et al.  An assessment of the differences between three satellite snow cover mapping techniques , 2002 .

[27]  Dan Tarpley,et al.  Mapping and monitoring of the snow cover fraction over North America , 2003 .

[28]  Larry L. Stowe,et al.  Scientific basis and initial evaluation of the CLAVR-1 global clear cloud classification algorithm f , 1999 .

[29]  D. Deaven,et al.  Changes to the Operational ''Early'' Eta Analysis / Forecast System at the National Centers for Environmental Prediction , 1996 .

[30]  D. Robinson,et al.  Global Snow Cover Monitoring: An Update , 1993 .

[31]  Robert Frouin,et al.  Estimating Photosynthetically Active Radiation (PAR) at the earth's surface from satellite observations , 1995 .

[32]  Geneviève Sèze,et al.  Effects of satellite data resolution on measuring the space/time variations of surfaces and clouds , 1991 .

[33]  Ivan Csiszar,et al.  Automated Monitoring of Snow Cover over North America with Multispectral Satellite Data , 2000 .

[34]  C. Long,et al.  SURFRAD—A National Surface Radiation Budget Network for Atmospheric Research , 2000 .

[35]  C. H. Whitlock,et al.  Radiative flux opens new window on climate research , 1995 .

[36]  Gary G. Gibson,et al.  A Climatology of Surface Radiation Budget Derived from Satellite Data , 1999 .

[37]  J. Townshend,et al.  Global land cover classi(cid:142) cation at 1 km spatial resolution using a classi(cid:142) cation tree approach , 2004 .

[38]  R. Pinker,et al.  Evaluation and Comparison of MODIS and IMS Snow-Cover Estimates for the Continental United States Using Station Data , 2005 .

[39]  B. Hicks,et al.  The NOAA Integrated Surface Irradiance Study (ISIS) - A new surface radiation monitoring program , 1996 .

[40]  R. Pinker,et al.  An EOF Iteration Approach for Obtaining Homogeneous Radiative Fluxes from Satellites Observations , 2007 .

[41]  William B. Rossow,et al.  Calculation of surface and top of atmosphere radiative fluxes from physical quantities based on ISCCP data sets: 2. Validation and first results , 1995 .

[42]  Philip A. Durkee,et al.  Snow/Cloud Discrimination with Multispectral Satellite Measurements , 1990 .

[43]  B. Ramsay,et al.  The interactive multisensor snow and ice mapping system , 1998 .