Radiative Forcing, Satellite Validation, and Thermodynamic Impact of Aerosols during Aerose Campaigns

An estimated three billion metric tons of mineral aerosols are injected into the troposphere annually from the Saharan desert [Prospero et al., 1996]. These windswept aerosols from the African continent are responsible for a variety of climate, health, and environmental impacts on both global and regional scales that span the Western Hemisphere [Morris et al., 2006]. The Aerosol and Ocean Science Expeditions (AEROSE) are a great opportunity to tackle these impacts. The Saharan Air Layer (SAL) appears to retain its Saharan characteristics of warm, stable air near its base, and dryness and dustiness throughout its depth as it is carried as far as the western Caribbean Sea [Dunion & Velden, 2004]. AEROSE provides insitu characterization of the impact of aerosols of African origin on energy balance and microphysical evolution of mineral dust outflow over the tropical Atlantic Ocean. By quantifying the radiative properties of the SAL, aerosol optical depths (AOD) as high as 1.6 was detected over the Atlantic [Nalli et al., 2011], producing a shortwave forcing of 200 W/m2 and therefore a warming just above the marine boundary layer for this particular case. Also in this study, AOD values from AEROSE have been compared with the Moderate Resolution Imaging Spectroradiometer (MODIS), showing variety on each campaign.