National Meteorological Center Hemispheric Meteorology Pepmerge Grid and Analysis

The National Meteorological Center uses binary packed data set organization when storing gridded data files. Different grid sizes are available (octogonal mercator and polar sterographic) for both the Northern and Southern Hemisphere. This binary format is used for storage of arrays of data, of typically gridded fields. In this format, fullword (32 bit 360/195) floating numbers are scaled and stored as halfword (16 bit) integers. The first 12 fullwords (48 bytes or 384 bits) of this format are the label portion, which serves two purposes: 1) it retrieved from the data set where it is stored, and 2) it contains the count and scaling information so that the data, which is stored in the remainder of the format, may be unpackedand converted back to a field of floating numbers. Documentation is the National Meteorological Center's Office Note 84 which explains in detail the many possible combinations of gids and their parameters. A related file is DSI-9934. This file is available for purchase from the NCDC. The only grids on this tape file are 145 X 37 global grids for all levels for both hemispheres.