ESTIMATING MIXING HEIGHTS OVER SOUTHERN AFRICA USING SURFACE-BASED MEASUREMENTS

A simple algorithm for calculating minimum and maximum mixing heights wing surface-based meteorological data is given Minimum and maximum mi xing heights thus calculated compare favourably with observed mixing h eights, as determined from upper-air soundings. Correlations of 0.74 ( 0.82) have been found between the calculated minimum (maximum) and obs erved mixing heights. Spatially, lowest (highest) minimum mixing heigh ts over South Africa are found over the central plateau (coastal) regi ons in both summer and winter: Highest (lowest) maximum mixing heights are found over the central and western plateau (coastal) regions duri ng both summer and winter.