A summary of ORACLES-deployments in 2016-2018 to study aerosol-radiation-cloud interactions in the South-East Atlantic
Abstract
Seasonal biomass burning (BB) in Southern Africa during the Southern hemisphere spring produces BB aerosol particles that eventually interact with the semi-permanent subtropical stratocumulus (Sc) cloud deck over the South-East (SE) Atlantic. While burned areas are decreasing globally, burned areas in Africa are increasing, raising interesting questions about BB aerosol interactions with climate in that region in the future. These interactions include cloud adjustments to aerosol-induced solar heating and microphysical effects. The representation of these interactions in climate models remains highly uncertain, because of the scarcity of observational constraints on both the aerosol and cloud properties, and poor understanding of the governing physical processes.
Three deployments involving the NASA P-3 and ER-2 aircraft in the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) project in September 2016, August 2017 and October 2018, are starting to fill this observational gap by providing an unprecedented look at the SE Atlantic cloud-aerosol system. We provide an overview of all deployments, highlighting aerosol absorptive and cloud-nucleating properties, their vertical distribution relative to clouds, the locations and degree of aerosol mixing into clouds, and cloud changes in response to such mixing. We assess the differences and similarities of the BB plume and cloud properties as observed from the 2016 deployment site (Walvis Bay, Namibia), and the 2017 and 2018 deployment site (Sao Tômé and Príncipe) near the plume's northern edge. We will conclude with the current status of the integrative work that addresses the overarching science questions regarding aerosol-radiation-climate interactions in the SE Atlantic and how the suborbital observations will aid long-term modeling and satellite measurement efforts.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A14E..02R
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0321 Cloud/radiation interaction;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES;
- 3359 Radiative processes;
- ATMOSPHERIC PROCESSES