Integrated Campaign for Aerosols, gases, and Radiation Budget (ICARB)

The Integrated Campaigns for Aerosols, gases and Radiation Budget (ICARB) is an integrated, multi-platform approach having aerosol measurements from aircraft, ship, and satellites; in addition to the regular ARFINET observations to quantify the heterogeneity of aerosols. Conceived as a series of mega-campaigns under ICARB, the first of it was conducted during March-May 2006, covering about 4 million km² oceanic area of Bay-of-Bengal, North Indian Ocean, and Arabian Sea, followed by the second one (W_ICARB) during December 2008 to January 2009 focusing on Bay-of-Bengal, with extensive concurrent airborne measurements and are the biggest campaigns ever conducted for aerosol impact assessment.

ICARB, conceived following an integrated-segmented approach, comprised of three observation-intensive segments; viz., (a) the land segment, (b) the ocean segment and (c) the air segment.

• The land segment comprised of fixed aerosol observatories, making continuous time series measurements of several aerosol parameters following a common protocol.
• The ocean segment comprised of the measurements of more than 20 aerosols and trace gas parameters, using about 40 different instruments by a team of 100 scientists from 26 national laboratories, academic institutions, and universities.
• The air segment was executed using NRSC aircraft, which comprised of 26 sorties from five base stations profiling the aerosol parameters vertically and spatially during the first phase (ICARB) and 17 sorties during the second phase (W-ICARB).

W-ICARB mainly aimed at examining the season-specific changes in the characteristics of the aerosol, brought about by the changes in the synoptic conditions, human activities, forest fires, and stronger vertical confinement of aerosol by a shallow winter atmospheric boundary layer arising out of highly subdued thermal convections during this season, which are in sharp contrast to those in spring. Going farther to the east than the ICARB, W-ICARB examined the aerosol properties over far eastern and south-eastern Bay-of-Bengal for the first time and brought out the important role of advection of anthropogenic aerosols from these regions over to the BoB, especially in view of the observed advection of anthropogenic aerosols from East Asian regions.

More recently in January-February 2018, ICARB-3 has been carried out over the South Arabian Sea and the Indian Ocean with one of the objectives being to delineate continental contribution to the open ocean aerosol loading and consequent radiative implications.