Precipitation Rate Computations in the Tropics by the Global Heat Budget Technique from 1 June 1984 - 31 May 1987
Abstract
This thesis presents monthly maps of computed precipitation rates over the tropics (30 deg N to 30 deg S) which were derived from the apparent heat source (Q sub 1) budget method. The data set used was the WMO archive version of the ECMWF global analysis data set for the period, 1 June 1984 - 31 May 1987. The Q sub 1-budget technique computes the total derivative of grid- scale dy static energy at increments of 2.5 deg longitude by 2.5 latitude at seven pressure levels (1000, 850, 700, 500, 300, 200 and 100 mb). When vertically integrated this quantity is equivalent to the total diabatic heating. Values of some of the diabatic heating terms are estimated and used in conjunction with mean monthly OLR values, generated from NOAA daily polar orbiter data, to solve for precipitation as the residual in the budget equation. Annual precipitation rate maps are presented and compared with annual average maps from atlases by Jaeger and by Dorman and Bourke, as well as limited island station data. The results compare favorably with both atlases and show an average error of 15% when compared to a ten year annual average of observed island and coastal station data. The computed precipitation rates were latitudinally averaged and compared to Dorman and Bourke's results for January, July, and annual means. In addition, time series of monthly-averaged precipitation rates are shown and discussed with regard to spatial and temporal variations, for selected regions, with particular attention devoted to the Southern Hemisphere.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1990
- Accession Number
- ADA227729
Entities
People
- Keith H. North
Organizations
- Air Force Institute of Technology