The discovery of the capability to detect aerosol absorption from space using near-UV observations was one the most important breakthroughs of the last decade in aerosol remote sensing from space. The technique, developed from analysis of observations by the TOMS instrument, has been extensively used for the global mapping of absorbing aerosols. Aerosol absorption can be measured from space in the near-UV by taking advantage of the interaction between molecular scattering and particle absorption. As a result of that interaction, it is possible to clearly detect the presence of absorbing aerosols under most observing conditions: clear skies over water and land surfaces (including deserts), mixed with clouds or above them, and aerosols over ice and snow-covered surfaces. For soot-containing aerosols, the near-UV aerosol absorption signal is a proxy of an important radiative transfer effect of significance not just in the near-UV but also in the visible and near-IR. The currently deployed observational capability of the A-train that includes radiance measurements from the near-UV (Aura-OMI) to the near-IR (Aqua-MODIS) as well as CALIPSO data, offers a unique opportunity for the synergistic use of satellite observations to characterize aerosol absorption.

Results of the application of the near-UV approach using OMI observations will be presented, and the potential of extending this retrieval capability to conditions where the aerosols are mixed with clouds or over snow/ice layers will be discussed.