Assessments of the Impact of Tropospheric Aerosols on Actinic Fluxes, Photosynthetically Available Radiation (PAR), and Radiative Forcing

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

As solar radiation travels through the atmosphere it can interact with small particles known as aerosols. These particles can scatter and absorb solar radiation, which affects the amount of radiation that reaches the Earth's surface. Solar radiation interactions with aerosols can also affect the chemistry of the atmosphere, such as through the creation and destruction of ozone. To better improve understanding and modeling of these interactions, the research team will use data collected by research aircraft over the past two decades alongside numerical modeling to answer questions about how aerosols interact with solar radiation over a range of altitudes, solar angles, and geographic settings. The results of the project will help to improve climate models. Additional benefits will be the education and training of a graduate student and the development of a database that can be used by other researchers. The research team will improve understanding of the impact of tropospheric aerosols on actinic fluxes and atmospheric composition by integrating and analyzing observed spectral actinic fluxes. The NCAR Charged-coupled devices Actinic Flux Spectroradiometer (CAFS) has flown on numerous field campaigns over the past two decades and the measurements from CAFS plus aerosol characterization measurements offers a unique opportunity to examine the impact of aerosols on photochemistry. The CAFS data, along with concurrent sub-orbital and satellite data, and modeling will be used to address the four main objectives: 1) Develop a new Aerosol Attenuated Actinic Flux (AAAF) database, 2) Perform an in-depth analysis of actinic fluxes in different aerosol-laden conditions, 3) Perform an analysis of the impact of smoke aerosol on the photosynthetically available radiation (PAR) and the UV-direct radiative forcing, and 4) Develop recommendations for climate models.