The GPROF 6.0 Pentads data set contains 5-day (pentad) averages of the GPROF 6.0 Gridded Orbits(which the reader should see for a description, including references). The pentads are computed for all useful data from all SSM/I sensors for the period January 1997 to the present. The latest pentads are typically computed about three days after the end of the pentad. Even though there have been at least two satellites for the entire period, sampling is sufficiently sparse that the data are averaged for pentads, then the pentads are smoothed with a 1-2-3-2-1 time-weighting. As noted in More Information (below), the last two pentads are unevenly weighted since the last (or last two) pentads in the average are not yet available. Consequently, the last two pentads must be recomputed when the next pentad becomes available.
The data set archive consists of unformatted REAL*4 binary files. Each file occupies 40 KB. The grid on which each field of values is presented is a 2.5°x2.5° latitude--longitude (Cylindrical Equal Distance) global array of points. It is size 144x72, with X (longitude) incrementing most rapidly west to east from the Prime Meridian, and then Y (latitude) incrementing north to south. Whole- and half-degree values are at grid edges:
First point center = (88.75°N,1.25°E)
Second point center = (88.75°N,3.75°E)
Last point center = (88.75°S,1.25°W)
Missing values are denoted by the value -99999. or -0.1, and the units of the rainfall are mm/hr.
The dataset curator is:
Eric J. Nelkin
Code 612
NASA Goddard Space Flight Center
Greenbelt, MD 20771 USA
Phone: +1 301-614-6311
Fax: +1 301-614-5492
Internet: eric.j.nelkin@nasa.gov
More Information
Pentad Data (1997 - present)
Pentad Anomaly Data (1997 - present)
Pentad Climatology Data