MONITORING GLOBAL VEGETATION USING NIMBUS-7 37 GHZ DATA - SOME EMPIRICAL RELATIONS

The difference of the vertically and horizontally polarized brightness temperatures observed by the 37 GHz channel of the Scanning Multichannel Radiometer (SMMR) on board the Nimbus-7 satellite are correlated temporally with three indicators of vegetation density. We find the SMMR 37 GHz and AVHRR (Advanced Very High Resolution Radiometer) provide complementary data sets for monitoring global vegetation, the 37 GHz data being more suitable for arid and semi-arid regions as these data are more sensitive to changes in sparse vegetation. The 37 GHz data might be useful for understanding desertification and indexing CO//2 exchange between the biosphere and the atmosphere.