Characterization of Saharan Air Layer with a Combination of Decade-long Aerosol Reanalysis, Satellite Products and in situ Observations
Abstract
The Saharan Air Layer (SAL) influences large-scale environment over the tropical north Atlantic and the Caribbean basins. Often it carries large amounts of dust aerosols, which is used as an indicator of SAL in the literature. The SAL is still a subject of ongoing study and research; however its definition is vague and varies among researchers. The emergence of a decade-long aerosol reanalysis dataset, the Navy Aerosol Analysis and Prediction System (NAAPS) Aerosol Optical Thickness (AOT) reanalysis, enables quick identification of dust-laden SAL events. It utilizes a modified NAAPS at its core and assimilates quality controlled retrievals of AOT from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua and the Multi-angle Imaging SpectroRadiometer (MISR) on Terra. Along with satellite-retrieved total precipitable water product, meteorological reanalysis (ERA-interim) and Caribbean region sounding observations, the AOT reanalysis is used for characterization of dust-laden SAL from statistical and climatological point of views. Another method for screening SAL relies on atmospheric thermodynamic features using sounding data. The two methods of defining SAL events, one based on aerosol features and the other on thermodynamics, are compared in the context of meteorological and aerosol environments. To what extent dust aerosol can be used as an indicator of SAL, is discussed. These results have implications for the study of SAL and its impacts on other meteorological and climate phenomena, eg., tropical cyclones.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A21E0130X
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSESDE: 1631 Land/atmosphere interactions;
- GLOBAL CHANGE