Derivation and validation of the seasonal thermal structure of Lake Malawi using multi-satellite AVHRR observations

Abstract

Lake Malawi is the second largest lake in Africa by volume and an important regional source of food. Seasonal fluctuations in the primary production of the lake are principally controlled by the lake's thermal structure, which modulates the mixing of nutrient-rich deep water with that of the phytoplanktonrich near-surface layer. Satellites potentially offer an efficient, low cost method of providing information on the lakes thermal structure over the longer term via remote sensing observations of lake surface temperature. Here we investigate the accuracy of remotely sensed lake surface temperatures derived using data from the NOAA-11 AVHRR over a two-year period (1992-1993). Optimised triple window atmospheric correction algorithms are shown to provide an accuracy of around 0.5°C when compared to in situ