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GES DISC DAAC Data Guide:
UARS UKMO Correlative Summary

Correlative assimilation data from the U.K. Meteorological Office (UKMO) are included as supplementary data products to the UARS Project. The main use of the correlative assimilation data is to provide an independent analysis for comparison with data from the UARS instruments. The analysed fields will be used as the basis for diagnostic studies of the circulation of the middle atmosphere.

The numerical model used in the assimilation system is a global primitive equation model, with a split-explicit time integration scheme. It incorporates a comprehensive range of physical parameterization schemes. It uses a hybrid vertical coordinate system, with terrain-following model levels at low levels, gradually changing to pressure levels in the stratosphere. The input to the assimilation system are from the World Weather Watch network of surface and upper air observations and satellite data.

The UKMO correlative assimilation data products consists of one data file per day containing the following parameters:

  1. TEMP atmospheric temperature, degrees K
  2. HEIGHT geopotential height, m
  3. ZONWIN_P westerly (zonal) wind component, m/s
  4. MERWIN_P southerly (meridional) wind component, m/s
  5. OMEGA vertical velocity, Pa/s
NOTE: Vertical velocity is available in files dated 26 August 1992 onwards.

Data coverage is global for the UKMO correlative assimilation data products. The horizontal resolution is 2.5 degrees latitude by 3.75 degrees longitude, using a staggered grid system. For parameters other than wind components, each horizontal field consists of 73 rows of 96 points, starting at 90N, 0E. The wind data are staggered by half a grid, starting at 88.75N, 1.875E (with 72 rows).

The fields have been placed at the UARS standard pressure levels, where the pressure levels are defined by P(i) = 1000*10**(-i/6), i=0,1,2,... , where i is the index into the data array. Vertical coverage for the UKMO correlative assimilation data is from 1000 mb to 0.316 mb.

Change History

Version 2.0
Version baselined on addition to the GES Controlled Documents List, May 5, 1998.


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  • Last updated: June 19, 2006 18:55:20 GMT