Aerosol characterization: comparison between measured and modelled surface radiative forcing over Bay of Bengal

Under the aegis of Indian Space Research Organisation's ongoing climate change research programme, Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) was undertaken from 27 December 2008 to 30 January 2009 over the Bay of Bengal (BoB). Since measurements of this sort have not been made near the eastern-most coastline of BoB, a cruise was planned to have observations along the boundaries of the BoB. Here we report the columnar aerosol optical thickness (AOT), total water vapour (TWV), total ozone column (TOC) and aerosol direct surface forcing calculations by using a pair of handheld Microtops II (Ozonometer and Sunphotometer) and a gimbal-mounted short-wave (SW) pyranometer, with high temporal resolution (5 minutes). The presence of high aerosol loading and absorbing aerosols over the coastal and Andaman regions resulted in a diurnal mean aerosol surface radiative forcings of -24 and -35 W m(-2), respectively. These results are in good agreement with radiative transfer model estimations.