GEWEX-RFA Data Set Description
------------------------------

Data product name:  (<ProductName>_<ProductVersion>)
   
   UMD-SRB_Ed031


1) Contact for scientific questions about data

Name:            Dr. Rachel T. Pinker
Address:         Department of Atmospheric and Oceanic Science
                 University of Maryland College Park, MD 20742
Telephone:       301-405-5380
E-mail address:  pinker@atmos.umd.edu
URL:             http://www.atmos.umd.edu/~pinker



2) What is the name of the original archived data set from which this
     GEWEX-RFA subset was produced?

   ------
   The original archived data set is UMD/SRB V3.1 (University of 
   Maryland/Surface Radiation Buget Dataset).
   
3) Is the original archived data set currently available from another
     data center or web site?
     If so, please list addresses or URLs:

   ------
   An earlier version of the data set is available from the following
   web site:

   http://www.atmos.umd.edu/~srb/pathfinder/04ava-data.htm   
   

4) Brief data description:  A reference or URL for the complete original
     archived data set documentation, followed by a brief summary of
     features of particular relevance to the RFA submission (such as 
     gap filling method), is the preferred approach.
     (Items of interest: input data streams, name of algorithm used to
     produce data, start and end time of data, gaps in spatial or temporal
     coverage, and data quality issues, etc.).

   ------
   The data set was produced with the UMD/SRB Model (V3.1) developed
   at the University of Maryland. Version 1.1 (V1.1) is described in 
   Pinker and Laszlo (1992). This version was subsequently modified and
   an update (V2.1) was documented and submitted to NASA LaRC. So far,
   the current version (V3.1) has been implemented only at UMD and a 
   manuscript describing it is in preparation. This product is a
   uniform long term (1983/07 to 2004/12) global coverage data set 
   from numerous satellites. The inference techniques estimate the      
   surface and top of atmosphere (TOA) short-wave (SW) fluxes using 
   ISCCP satellite observations. The method is based on radiative
   transfer theory, and produces direct and diffuse fluxes in five
   spectral intervals in the range of 200-4000 nm. The radiative
   transfer model accounts for the absorption and scattering processes
   occurring in the atmosphere and for the interaction of the radiation
   with the surface. The radiative fluxes at the boundaries of the
   atmosphere are computed by determining the atmospheric transmission
   and reflection (optical functions) and the surface albedo, 
   pertaining to a particular satellite observation. The retrieved 
   optical functions, along with the surface albedos are then used to 
   compute the fluxes for clear and cloudy conditions, independently. 
   The all-sky flux is obtained by using information on cloud cover. 
   The current data set (Version 3.1) includes improved parameterization 
   of water vapor absorption, a new aerosol climatology, correction of
   topographic effects, as well as improved techniques for replacing
   missing observations. Some other items about the data set:
   * 2.5 degree global maps beginning at the South Pole and
     international dateline (90S,180W), incrementing eastward and then
     northward for a total of 10368 global grid cells;
   * monthly mean on local standard time from July 1983 to December 2004;
   * missing values: -9999.0
   
   

5) History of updates and changes. If you resubmit a new version of
     any part of this data product to GEWEX-RFA, please use this space to
     record the reasons for the new submission (i.e., fixed error in___
     parameter; changed to area-weighted spatial averaging, etc.) Please
     specify the parameter(s) affected, new RFA number(s), and the date of
     the change.

   ------
   N/A


6) Please provide a list of publications and journal articles pertaining
     to these data (if any); or a link to a bibliography for the product.

   -----
   http://www.atmos.umd.edu/~srb/


7) If you would like a specific citation or acknowledgment when these
     data are used in a publication, please provide that here:

   ------
   The following citation or acknowledgment when using these these data  
   in a publication should be used: "UMD/SRB Data used in this 
   study/project have been provided by the University of Maryland 
   Surface Radiation Budget Group, R. T. Pinker, PI".

 
8)  Please indicate below all data types currently included in the GEWEX-RFA
      archive for this data product.

A) Top of atmosphere data products
          ___*__ Maps (Parameters: All-sky SW down, All-sky SW up)
          _____ Time series (Parameters: list here)

B) Surface data products
          ___*__ Maps (Parameters: All-sky SW down, All-sky SW up)
          _____ Time series (Parameters: list here)

C) Ground-based measurements
          _____ Time series (Parameters: list here)

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Tel: (757) 864-8656
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Internet: larc@eos.nasa.gov
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