The primary objectives of this project are: 1) To characterize major processes controlling the chemical, physical, and optical properties of near-surface aerosols, including elemental and organic carbon (EC/OC), over the western North Atlantic Ocean; 2) To quantify long-term trends in aerosol concentrations and fluxes and assess their influences on climate forcing; and 3) To provide data for and to collaborate with (a) the modeling community to develop reliable predictive capabilities for direct climate forcing by aerosols and (b) the remote sensing community to improve the accuracy of algorithms used to retrieve atmospheric and oceanic information. Super- and sub-micron diameter aerosols will be sampled daily at Bermuda and analyzed for EC/OC, spectrally resolved absorption, major organic and inorganic ions, and mineral aerosol mass. Aerosol light scattering will be measured continuously, and wet-deposition fluxes of major ions and EC/OC will be quantified. In collaboration with NASA, profiles of aerosol backscatter, extinction, and cloud height will be measured continuously. Three-dimensional back trajectories will be calculated and clustered into characteristic transport regimes. Data will be integrated into climatologies of aerosol chemical, physical, and optical properties as a function of transport regime, and long-term trends will be evaluated. Individual cases representative of major regimes will be interpreted in conjunction with satellite-derived humidity and aerosol optical depth fields and infrared (IR) cloud fields.
This effort will enhance efforts to predict the influence of changing aerosol composition on radiative transfer and, in turn, on meteorology and climate. Broader impacts also include training of undergraduate and graduate students in atmospheric chemistry and physics.
