A Diagnostic Model for Estimating Large-Scale Flow Patterns in the Tropical Upper Troposphere from Satellite Cloud Brightness Data
MetadataShow full item record
A diagnostic model is proposed to use digitized satellite cloud brightness data to estimate objectively the large-scale flow patterns over data-void tropical regions. The model utilizes a linear barotropic vorticity equation with two primary assumptions: 1) that the area-averaged cloud brightness is positively correlated with large-scale divergence in the tropical upper troposphere; and 2) that the large-scale tropical flow is quasi-barotropic and quasi-non-divergent. It is designed to be used at any upper tropospheric level where divergence is important in determining the vorticity field. Three types of information are required: 1) boundary conditions determined from surrounding wind reports, 2) a mean zonal flow determined from climatology, and 3) an equivalent divergence forcing function constructed empirically from the brightness data. The model is tested daily over a western North Pacific region for July-August 1971. Results for an 8-day representative period are presented and discussed. In general for 25% of the days tested, the model produces a flow field which accurately resembles the major features of the streamfunction field analyzed by the National Meteorological Center. In another 30% of the days it provides some valuable information about the flow patterns which would be difficult to obtain from boundary information alone. Experiments are also performed for two days in which the brightness data are enhanced by time-interpolated satellite infrared data. The resultant fl.ow fields bear better resemblance to the NMC analysis. It is thus suggested that improved results may be expected when infrared and other types of advanced satellite data are available.
The article of record as published may be found at http://dx.doi.org/10.1175/1520-0493(1975)103<0536:ADMFEL>2.0.CO;2
Showing items related by title, author, creator and subject.
Application of satellite cloud brightness data for large-scale tropical analysis: A correlation study of brightness and 200-mb divergence Chang, Chih-Pei (Monterey, California. Naval Postgraduate School, 1974 -08); NPS-51Cj74081This is a preliminary analysis of digitized satellite cloud brightness data that will be used in developing a model for large-scale analysis over data-void tropical areas, which is based on Wallace's (1971) postulation that ...
An objective technique for estimating large-scale flow pattern in the tropical upper troposphere from digitized cloud brightness data. Jacobs, Frederick T. (Monterey, California. Naval Postgraduate School, 1974);An objective technique is proposed to use digitized satellite cloud brightness data to estimate large-scale flow patterns over data-void tropical regions. It is basically a diagnostic model which assumes: 1) area-averaged cloud ...
A case study on the use of digitized cloud brightness to represent large-scale convection in the tropics Edwards, Bruce B. (Monterey, California. Naval Postgraduate School, 1973-12);Digitized cloud brightness data for July 1969 are examined to determine the degree of relationship between organized brightness patterns and the large-scale convection field in the tropical western North Pacific. Correlation ...