Using combined CALIPSO/AMSR-E/MODIS/CERES data to interpret aerosol-climate interaction record

Recent studies of Antarctic ice core record (Rothlisberger et al, 2008) indicate correlations between Antarctic warming (cooling) and the reduction (increase) of dust (Ca) and sea salt (Na) deposited during the last 800,000 years. While changes in ocean surface wind speeds are suggested as being responsible for the correlation of the dust decrease and warming, the sea-salt decrease and warming correlation is considered as a proxy for the relation between warming and changes in sea ice. In this paper we ask whether there are other possible explanations for the observed correlations between aerosols and temperature change? We intend to link the interaction between ocean surface winds to CO2 uptake, aerosol, cloud, and radiation to the recently observed correlation. The hypothesis is this: orbital perturbations cause changes in temperature, at a certain point it triggers changes in atmospheric dynamics and ocean surface wind speed. These in turn cause changes in CO2 uptake (and temperature) and temperature feedback, and at the same time the wind speed change causes changes in the amount of sea salt and dust transported to the polar region. The key to this hypothesis is the correlation between ocean surface wind speed and sea salt transport, and this is the focus of our study. We first describe an aerosol optical depth retrieval using CALIPSO ocean surface backscatter and aerosol profiles, AMSR-E ocean surface winds, and MODIS water-leaving radiance. A simple relation between the optical depth and wind speed is established based on the retrieved results. Using this simple relation and an atmospheric model, the surface wind of Southern oceans is linked to aerosol fluxes of the polar region. The changes in ocean surface wind speeds are also linked to CO2 uptake and reflected sunlight in order to estimate temperature change and their correlation with the wind speeds and the aerosols. The wind - sea salt aerosol relation revealed in this study suggests that the sea salt record may be a proxy for the high latitude ocean surface wind speed (and CO2 uptake) record.