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ISLSCP II Surface Radiation Budget (SRB) Radiation Data

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Revision date: December 9, 2013


This data set contains global Surface Radiation Budget (SRB) and a few top-of-atmosphere (TOA) radiation budget parameters on a 1-degree x 1-degree spatial resolution. These parameters are provided as monthly, monthly-3 hourly (i.e. monthly average for a particular 3 hourly period) and 3-hourly averages. All monthly parameters include files with a monthly mean value, a monthly standard deviation, and monthly minimum and maximum values.

The surface and TOA Shortwave (SW) radiative parameters were computed with the Pinker and Laszlo (1992) radiation model. The Longwave (LW) SRB parameters were derived with the Gupta et al. (1992) model. Meteorological inputs for all processing were taken from the Goddard Earth Observing System version 1 (GEOS-1) reanalysis data sets (Schubert et al., 1993) from the Data Assimilation Office (DAO), at NASA Goddard Space Flight Center (GSFC). Required cloud parameters were derived at NASA Langley Research Center (LaRC) from International Satellite Cloud Climatology Project (ISCCP) DX data using the algorithms developed at the NASA Goddard Institute for Space Studies (GISS) (Rossow et al., 1996). Surface albedos are derived internally in the Pinker and Laszlo SW model.

There are 30 compressed data files (*.zip) with this data set. When the *.zip files are expanded, there are 114,912 3-hourly files, 42,064 diurnal files, and 6,254 monthly files.

Additional Documentation:

This data set is one of the products of the International Satellite Land-Surface Climatology Project, Initiative II (ISLSCP II) data collection which contains 50 global time series data sets for the ten-year period 1986 to 1995. A complete description of the data, it's derivation, acknowledgements, and references provided by the ISLSCP II Data Management Staff is included with this data set as a companion file named 1_srb_radiation_clouds_doc.pdf .

ISLSCP II is a consistent collection of data sets that were compiled from existing data sources and algorithms, and were designed to satisfy the needs of modelers and investigators of the global carbon, water and energy cycle. The data were acquired from a number of U.S. and international agencies, universities, and institutions. The data and documentation have undergone two peer reviews.

ISLSCP is one of several projects of Global Energy and Water Cycle Experiment (GEWEX) [] and has the lead role in addressing land-atmosphere interactions -- process modeling, data retrieval algorithms, field experiment design and execution, and the development of global data sets.

Data Citation:

Cite this data set as follows:

Stackhouse, P.W., and S.K. Gupta. 2013. ISLSCP II Surface Radiation Budget (SRB) Radiation Data. Data set. Available on-line [] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA.

File Information:

The archived data sets for ISLSCP II have been organized by categories. This data set is in the radiation-clouds category.

Data Set Spatial Extent: Global

Westernmost Longitude: -180 W

Easternmost Longitude: 180 E

Northernmost Latitude: 90 N

Southernmost Latitude: -90 S

Projection: Geographic

Data Set Spatial Resolution: one degree in both latitude and longitude

Data File Format

All of the data files in each data set within the ISLSCP Initiative II data collection are in ESRI ASCII grid format for ArcInfo. The file format consists of numerical fields of varying length, which are delimited by a single space and arranged in columns and rows.

There are 30 *.zip files with this data set. Each uncompressed file contains space-delimited ASCII text with 360 values per line and 180 lines of data (1-degree resolution). Each line is terminated by a newline character. The data are structured so that the upperleft corner of the first pixel is located at 90 degrees North latitude and 180 degrees  West longitude. Each pixel represents a 1 by 1-degree area, with the pixel edges falling on whole degree boundaries.

The files contain a variety of different data types, listed in the table below.

File Abbrev. Type of Data Temporal Coverage
calb clear-sky surface albedo monthly
cdsf clear-sky downward sw flux monthly, diurnal
dif all-sky diffuse sw flux monthly, diurnal
dlf all-sky downward lw flux monthly, diurnal, 3-hourly
dsf all-sky downward sw flux monthly, diurnal, 3-hourly
nlf all-sky net lw flux monthly, diurnal, 3-hourly
nsf all-sky net sw flux monthly, diurnal
ntf all-sky net total flux monthly, diurnal
par all-sky par flux monthly, diurnal
sfal all-sky surface albedo monthly
tin toa insolation monthly, diurnal
trsf toa reflected sw flux monthly, diurnal
ulf surface upward lw flux monthly, diurnal
usf surface upward sw flux monthly


Data file names:


When the *.zip files are expanded, there are 114, 912 3-hourly files, 42,064 diurnal files, and 6,254 monthly files.

Please refer to the companion files 1_srb_radiation_clouds_doc.pdf and srb_radiation_datafile_information.pdf for information regarding the data file naming conventions and number of files per variable and temporal coverage.

Data Access:

These data are available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC)  [].

Data Archive Contact Information:

Telephone: +1 (865) 241-3952


Pinker, R.T., and I. Laszlo, 1992: Modeling surface solar irradiance for satellite applications on a global scale. J. Appl. Meteor., 31, 194-211.

Gupta, S.K., W.L. Darnell, and A.C. Wilber, 1992: A parameterization of longwave surface radiation from satellite data: Recent improvements. J. Appl. Meteorol., 31, 1361-1367.

Rossow, W.B., A.W. Walker, D.E. Beuschel, and M.D. Roiter, 1996: International Satellite Cloud Climatology Project (ISCCP): Documentation of new cloud data sets. WMO/TD-No. 737, World Meteorological Organization, 115 pp.