Revision date: November 23, 2009

Summary:

The goals of the Earth Radiation Budget Experiment (ERBE) are (1) to understand the radiation balance between the Sun, Earth, atmosphere, and space and (2) to establish an accurate, long-term baseline data set for detection of climate changes. Earth Radiation Budget (ERB) data are fundamental to the development of realistic climate models and to the understanding of natural and anthropogenic perturbations of the climate system. As part of ERBE, measurements of broadband shortwave radiation reflected from the Earth-atmosphere system were obtained, from which top of atmosphere albedo values were calculated. In addition, values from scenes determined to be free of clouds were analyzed separately and clear-sky albedos were derived. For this study, only the clear- -sky albedos are included. The ERBE data sets for the International Satellite Land Surface Climatology Project (ISLSCP) Initiative II contain global, top of atmosphere, clear sky albedo data from January 1986 to February 1990 at 2.5 degree spatial resolution, regridded to a 1 degree spatial resolution.

This data set contains ten *.zip files named erbe_albedo_orig_YYYY.zip and/or erbe_albedo_1deg_YYYY.zip, where YYYY = year, 1986 through 1990. Each zip when extrapolated contains twelve *.asc files, one for each month of the given year in standard ESRI ARCGIS ArcInfo ASCII grid format. Note that data are not provided for March 1990 through December 1990.

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. Selected data sets span even longer periods. A complete description of the data, their derivation, acknowledgements, and references provided by the ISLSCP II Data Management Staff is included with this data set as a companion flie named 1_erbe_albedo_monthly_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) [http://www.gewex.org/] 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:

Barkstrom, B.R. 2009. ISLSCP II Earth Radiation Budget Experiment (ERBE) Monthly Albedo, 1986-1990. In Hall, Forrest G., G. Collatz, B. Meeson, S. Los, E. Brown de Colstoun, and D. Landis (eds.). ISLSCP Initiative II Collection. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/957

 

Data Description:

The archived data sets for ISLSCP II have been organized by categories. This data set is in the vegetation category--a collection of vegetation and albedo data sets.

Data Set Spatial Extent: Global gridded

Western most Longitude: -180 W

Easternmost Longitude: 180 E

Northernmost Latitude: 90N

Southernmost Latitude: -90S

Projection: Geographic

Data Set Spatial Resolution: 1 degree and 2.5 degree in both latitude and longitude

Data Set Temporal Extent: January 1986 through February 1990

Data Set Temporal Resolution: Monthly

 

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 six lines of header information followed by numerical fields of varying length, which are delimited by a single space and arranged in columns and rows. The 1 degree files in this data set are on a 1 degree by 1 degree grid and contain 360 columns by 180 rows. The 2.5 degree files are on a 2.5 degree by 2.5 degree grid and contain 114 columns by 72 rows. All files are gridded to a common equal-angle latitude/longitude grid.

 

The following files are included in this data set:

erbe_albedo_orig_YYYY.zip. Contains 12 *.asc files in ESRI ASCII GRID format for ArcInfo with the original ERBE monthly clear-sky top of atmosphere albedos (unitless) at a 2.5 degree lat/long resolution.

erbe_albedo_1deg_YYYY.zip. Contains 12 *.asc files in ESRI ASCII GRID format for ArcInfo with the original ERBE monthly clear-sky top of atmosphere albedos (unitless) regridded to 1 degree lat/long resolution.

Within each zipped file each *.asc file is an albedo image for a given month.

Example: erbe_albedo_1d_19940400.asc is the albedo for April 1994.

Data file naming convention is described in: 0_erbe_albedo_readme.txt

 Data Values:

All values are written as floating point values.

Missing values are assigned the value of -99.00 on all data layers.

Data Access:

These data are available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC)  [http://daac.ornl.gov].

Data Archive Contact Information:

E-mail: uso@daac.ornl.gov
Telephone: +1 (865) 241-3952

 

References:

Hall, F.G., E. Brown de Colstoun, G. J. Collatz, D. Landis, P. Dirmeyer, A. Betts, G. Huffman, L. Bounoua, and B. Meeson, The ISLSCP Initiative II Global Datasets: Surface Boundary Conditions and Atmospheric Forcings for Land-Atmosphere Studies, J. Geophys. Res., 111, doi:10.1029/2006JD007366, 2006.

Barkstrom, B. R., 1984. The Earth Radiation Budget Experiment (ERBE). Bull. Amer. Meteorol. Soc., 65:1170-1185.