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ISLSCP II Snow-Free, Spatially Complete, 16 Day Albedo, 2002
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Revision date: December 08, 2009

Summary

This data set contains 9 zip files of snow-free, spatially complete 16-day global black-sky albedos at local solar noon, white-sky albedos and quality information based on MODerate Resolution Imaging Spectroradiometer (MODIS) Collection 4 Albedo Products (MOD43B3). Data  are provided for 7 spectral bands and 3 broad bands for a full year of MODIS data (2002). An ecosystem-dependent temporal interpolation technique was developed to fill any missing or seasonally snow-covered data in the original Collection 4 (MOD43B3) albedo product. The resulting data set maintains the original resolution and data of the MOD43B3 product while replacing fill values to provide snow-free spatially complete maps.

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, their derivation, acknowledgements, and references provided by the ISLSCP II Data Management Staff is included with this data set as a companion file named 1_modis_fill_alb_2002_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

Moody, E.G., King, M.D., Schaaf, C.L., and Gao, F. 2009. ISLSCP II Snow-Free, Spatially Complete, 16 Day Albedo, 2002. In Hall, Forest 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/960


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: 1.0 degree, 0.5 degree, and 0.25 degrees in both latitude and longitude

Data Set Temporal Extent: January 2002 through December 2002

Data Set Temporal Resolution: Synoptic months

 

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. The files at different spatial resolutions each contain the following numbers of columns and rows:
      1.0 degree: 360 columns by 180 rows
      0.5degree: 720 columns by 360 rows
      0.25 degree: 1440 columns by 720 rows

Within the albedo files the pixel values are a real number. Values are albedo between 0 and 1.

Data Values:

All water bodies have a fixed value of -99.0000

Missing values over land are assigned the value of -88.0000

 

The data files fall into the following categories:

Black Sky Albedo (BSA) Surface black-sky albedo (directional hemispherical reflectance) at local solar noon derived from MODIS multidate surface reflectances provided for 7 spectral bands and 3 broadbands.
White Sky Albedo (WSA) White sky albedo (bi-hemispherical reflectance) for 7 spectral bands and 3 broadbands.
PC Percentage of original MOD43B3 data per grid cell.

Data File Names:

modis_filled_bsa_1d_2002.zip

modis_filled_bsa_hd_2002.zip

modis_filled_bsa_qd_2002.zip

modis_filled_perc_1d_2002.zip

modis_filled_perc_hd_2002.zip

modis_filled_perc_qd_2002.zip

modis_filled_wsa_1d_2002.zip

modis_filled_wsa_hd_2002.zip

modis_filled_wsa_qd_2002.zip

Data file naming conventions are described in the 0_modis_fill_alb_readme.txt

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