ISLSCP Initiative II

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Hydrology, Soils, & Topography Data

Global Precipitation Climatology Project (GPCP) Version 1 Pentad Precipitation

The Global Precipitation Climatology Project (GPCP) pentad version 1 precipitation data set includes global precipitation rates for 5-day, or pentad, periods. The data sets are derived from measured rain gauge data and merged with satellite estimates of rainfall. This is a portion of the version 1 GPCP pentad data set and covers the ISLSCP 2 period from 1986 to 1995. The original precipitation rates at 2.5 degrees were re-gridded to a 1 degree spatial resolution by the ISLSCP 2 staff.

Data Provider: GPCP and Pingping Xie (CPC)

Data Files (ISLSCP II Disc #1)

Data Set Documentation

Image Viewing Tutorial

File Information

The following files make up this data set:

• gpcp_pentad_orig_YYYYMMDD.asc: 730 files with the original GPCP pentad precipitation rates (mm/day) at a 2.5-degree resolution. Here YYYY is the year from 1986 to 1995, MM is the month from 01 to 12, and DD is the day for the starting date of the 5-day period that makes up each pentad. ***NOTE: For the leap years 1988 and 1992, the pentad period starting on 02/25 of every year (pentad #12) has six days and not five as all others.
• gpcp_pentad_1d_YYYYMMDD.asc: Same as gpcp_pentad_orig_YYYYMMDD.asc files but at a 1-degree spatial resolution.

ASCII Data Format

All files are in ASCII format. All values are written as floating point values with all values delimited by a single white space. Missing values are assigned the value of -999 on all data layers. All files are gridded to a common lat/long grid, where the coordinates of the upper left corner of the files are located at 180W, 90N and the lower right coordinates are located at 180 degrees E, 90 degrees S. The 2.5 degree original GPCP data sets are organized with 144 values per line and 72 total lines. The 1 degree resolution data sets contain 360 values per line and 180 lines.
      The data files are PKZip compressed. On UNIX, they can be decompressed using the "unzip -a" command. On Windows, they can be decompressed using WinZip or other PKZip software. On the Macintosh, they can be decompressed using Stuffit Expander.

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Revision Date: April 2, 2003