In this paper, we evaluate the performance of the chemical transport model ‘CHIMERE’ over large Indian region (4–37.5°N; 67–88.5°E) for multiple years (2006, 2007 and 2008) by comparing the model simulations with concurrent aerosol measurements from different locations. Model simulated nearsurface black carbon mass concentrations agreed satisfactorily with measurements at various locations (oceanic, inland and island sites), in general, except during monsoon months, when the model underpredicted the measurements.

In order to understand the regional climate implications of aerosols over Indo Gangetic Plains (IGP), a major Indo-US field experiment, Ganges Valley Aerosol Experiment (GVAX) was conducted during 2011– 12. Atmospheric Radiation Measurement (ARM) mobile facility (AMF) was deployed at the northern Indo-Gangetic Plain over the high-altitude site, Manora Peak, Nainital (29°21′33.84″N, 79°27′29.27″E, 1980 m amsl) in Central Himalayas, for an year-round measurement of aerosols, clouds and other climate-relevant atmospheric parameters.

Extensive measurements of columnar aerosol optical depth (AOD), composite (MT) and black carbon aero-
sol mass (MB) concentrations were made over the tropical Indian and Southern Oceans as a part of the
Pilot Expedition to the Southern Ocean during the boreal winter. The AOD, MT and MB show large lati-