During summer and pre-monsoon of 2004-2006, multi-institutional and multi-platform field campaigns were carried out over continental India
and adjoining oceans (Arabian Sea, Indian Ocean, and Bay of Bengal). A network of ground-based observatories, dedicated ship cruises and
altitude profiling over selected regions using instrumented aircrafts formed the three segments of this integrated experiment (namely land,
the ocean, and the air segments respectively), which were carried out in tandem. Large discrepancies were observed between the modeled
(which employed observed aerosol microphysical and optical properties) and measured surface (short wave) irradiances. Upward and downward looking
radiometers were used in aircrafts to measure the absorption in ten atmospheric layers (below 4 km). It was found from observations carried
out from the equatorial Indian Ocean to central Himalayas that during pre-monsoon season aerosol-induced warming at higher levels (> 2 km)
exceeds that at the surface layers by several degrees (K). This complex scenario arising due to the large contrast in aerosol-induced warming
between surface and atmospheric layers aloft, with (reflecting) clouds embedded in between, coupled with strong aerosol-induced surface cooling
suggests consequent impacts on regional climate. Major observations from field campaigns and implications are discussed in this seminar.