Retrieval of aerosol parameters using IRS P4 OCM data over the Arabian Sea and the Bay of Bengal

The recent first-field phase of Indian Ocean Experiment has provided various types of aerosol data over the Arabian Sea, the Bay of Bengal and the Indian Ocean. Using optical sensors on-board numerous satellites, global aerosol parameters have been estimated by many workers. In this communication, we have used IRS P4 OCM data to retrieve the aerosol parameters over the Arabian Sea and the Bay of Bengal. We also discuss the spatial, spectral and temporal variations of aerosol optical depth (AOD) over these regions. The Bay of Bengal shows more dynamic nature of aerosols compared to the Arabian Sea. Aerosol size-distribution shows unimodal nature during winter and bimodal nature during summer season. The spatial gradient of AOD is found to be higher over the Bay of Bengal compared to that over the Arabian Sea. A zone has been found over the Bay of Bengal, which shows low values of AOD (< 0.25) for all the months. The Bay of Bengal experiences much more aerosol loading and transport of aerosols from the Indian subcontinent compared to the Arabian Sea. An aerosol plume is found in the northwestern Arabian Sea during February to March, and it is found to be dispersed in April. The spectral distribution of AOD and the size distribution suggest that the Bay of Bengal is dominated by finer particles compared to the Arabian Sea.