Vinoj, V, Anjan, A, Sudhakar, M, Satheesh, SK, Srinivasan, J, Moorthy, KK (2007). Latitudinal variation of aerosol optical depths from northern Arabian Sea to Antarctica. GEOPHYSICAL RESEARCH LETTERS, 34(10), L10807.
Measurements of the spectral aerosol optical depths (AODs) were made over the Arabian Sea, Indian Ocean, Southern Ocean, and Antarctica during a trans-continental cruise experiment conducted during January to April 2006. Our investigations show that AODs ( at 500 nm) remain low ( <= 0.1) and steady in the Southern Indian Ocean ( 20 degrees S to 40 degrees S). In contrast, large latitudinal gradients exist north of 20 degrees S. The AODs increase nearly exponentially from similar to 0.1 near Antarctica to reach a value as high as 0.7 in the northern Arabian Sea ( similar to 15 degrees N). The latitudinal gradients were larger in summer than in winter. The comparison of measured daily optical depths with those retrieved from MODIS satellite sensor showed good agreement ( within similar to 0.02) for regions north of 40 degrees S. The AODs were higher over remote oceans between 40 degrees S to 60 degrees S ( MODIS observations) latitudes as a result of enhanced sea-salt production due to high winds associated with the 'Roaring Forties.'