Remote sensing of the lower atmosphere: G. L. Stephens, 1994, 523 pp. Oxford University Press, £60 hb, ISBN 0-19-508188-9

Abstract

All season multiyear characterization of the aerosol optical depths (AOD) & absorbing aerosol index (AI) was carried out over Indian subcontinent using simultaneous data from MODIS satellite sensors. Significant spatio-temporal heterogeneity was found in the aerosol optical depths over Indian subcontinent. Latitudinal, MODIS derived Aerosol optical depths (AOD), its Small mode fraction (SMF, except pre monsoon) has shown increasing trends towards northern latitudes of Indian subcontinent. Pre monsoon mean AI values were found to increase linearly from a minimum of ~0.52 over the southern India region to a maximum of 3 over the central India region head at around 26.50 N at a rate of 0.001 per degree latitude while there was an exponential decay during winter and post monsoon. Longitudinally, the variations in the aerosol properties are subdued comparatively. SMF values tend to increase weakly towards eastern longitudes during all the seasons. Variations in the aerosol properties are parameterised using best fit analytical functions. By simultaneous examination of AI, AOD and SMF, it was inferred that the aerosol load was found responsible for the higher values of AI over Indian subcontinent during pre-monsoon which was further dominated by the transported UV-absorbing dust.