Estimates of the aerosol radiative forcing for three regions of World Ocean

Abstract

We present the results of numerical simulation of aerosol radiative forcing for three regions of the World Ocean: the coastal zone of Antarctica, the Sea of Japan, and the Sea of Darkness. The aerosol radiative forcing for separate regions of ocean was simulated using ship-based measurements of aerosol optical depth and atmospheric water vapor content. Data on the single scattering albedo and asymmetry factor of scattering phase function are presented according to model simulations (coastal zone of Antarctica: OPAC model) and multiyear observations at AERONET photometer stations (the Sea of Japan: Noto site; and the Sea of Darkness: Cape Verde site). The calculations showed that the cooling effect of aerosol over Sea of Japan/Sea of Darkness at the atmospheric boundaries increases by about an order of magnitude as compared to the clean atmosphere near Antarctica. At the same time, the daily average values of the aerosol radiative forcing vary as follows: from −2.3 (Antarctica) to −30.3/−32.6 W/m2 (Sea of Japan/Sea of Darkness) at the surface level and from −1.9 to −16.1/−18 W/m2 at the top of the atmosphere. The estimates obtained agree reasonably well with the results of other authors.