Direct Aerosol Radiative Effects and Heating Rates: Results from the 2016 and 2017 ORACLES Field Campaigns
Abstract
The Southeast Atlantic contains a large, semi-permanent cloud deck often overlaid by a thick layer of biomass burning aerosols that has been advected westward from Southern Africa. We will present (a) the direct aerosol radiative effect (b) the albedo value for which the radiative effect transitions from warming to cooling, i.e., the critical albedo, and (c) aerosol and gas absorption and heating rates for this region from the 2016 and 2017 deployments of the NASA ORACLES experiment (ObseRvations of CLouds above Aerosols and their intEractionS). Observations by the Solar Spectral Flux Radiometer (SSFR), Enhanced MODIS Airborne Simulator (eMAS), High Spectral Resolution Lidar (HSRL-2,) and the Spectrometer for Sky-Scanning Sun-Tracking Atmospheric Research (4STAR) are put into context by the 3D radiative transfer model Monte Carlo Atmospheric Radiative Transfer Simulator (MCARaTS), which allows us to determine the aerosol radiative effect especially when inhomogeneous clouds are present. For highly homogeneous scenes, a direct derivation from the measurements is also possible. We give an overview of spectral single scattering albedo, Ångström exponents, and heating rate profiles for the two experiments while also exploring the dependence of the critical albedo on the aerosol properties.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.A14B..05C
- Keywords:
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- 0321 Cloud/radiation interaction;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES;
- 3355 Regional modeling;
- ATMOSPHERIC PROCESSES;
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES