A Study of Objective Analysis Techniques for Meteorlogical Fields

摘要

Pilot analyses are performed, using 500-mb height, wind, and temperature data from a complex of 35 tropical weather stations. Specifically, raw covariances of upper-air wind, height, and temperature for the Caribbean are smoothed onto a 16-by-32 rhombic computational grid. These covariance data are analysed, using the fast Fourier transform, and adjusted to satisfy the balance equation. Adjusted spectral data are used in objective analysis algorithms to evaluate alternative observation networks. The NMC (National Meteorological Center) objective analysis scheme and optimal sequential analysis techniques are compared with respect to their application to two-dimensional diffusion fields. Algorithms based on the theory of optimal sequential analysis are also obtained for raster scan and for casual updating of diffusion fields. Prefiltering techniques are discussed. The results of some numerical experiments on the NMC algorithm and the application of optimal analysis techniques to data from nonlinear processes are presented. (Author)