Aerosol radiative properties using recently available high-quality columnar aerosol data collected at several AERONET sites in South Asia, with a focus on pollution outflow from continental South Asia observed over Hanimaadhoo in Maldives, a small island in northern Indian Ocean are quantified. The seasonal mean aerosol optical depth (AOD) over Hanimaadhoo is >= 0.3 (except ca. 0.2 during monsoon season), and single scattering albedo (SSA) is > 0.90 in all seasons. Fine mode aerosols contribute dominantly to AOD. SSA decreases as a function of wavelength due to influence of continental aerosols, except during the monsoon season when its spectral trend reverses due to increase in dust. Carbonaceous aerosols dominate (>90%) contribution to absorption AOD (AAOD). Black carbon (BC) and brown carbon (BrC) contribute >75% and <25%, respectively, to AAOD due to carbonaceous aerosols. The observed seasonal mean aerosol radiative forcing at the surface (ARF(SFC)), at the top of the atmosphere (ARF(TOP)) and in the atmosphere (ARF(ATM)) is > -25 Wm(-2), > -20 Wm(-2) and similar to+20 Wm(-2), respectively. Aerosol loading and atmospheric heating have increased over this background site over the last decade. A regional-scale analysis of aerosol properties and radiative effects across and surrounding the Indo-Gangetic Plain (IGP) shows that AOD is >= 0.3 over entire region, and aerosols reduce seasonally 30-50 Wm(-2) of solar radiation reaching the surface, contributing significantly to solar dimming effect. The atmospheric solar heating rate due to aerosols (HR) is >= 1 K day(-1) across IGP. These high ARFs, ARFE(SFC) and HR, and increasing trends have significant implications to climate and hydrological cycle over South Asia and beyond.
