Type

Text

Type

Thesis

Advisor

Hameed, Sultan | Reed, Kevin A | Colle, Brian

Date

2017-12-01

Keywords

Atmospheric physics | African Dust | extreme precipitation | Atmospheric chemistry | high resolution modeling | Tropical cyclones

Department

Department of Marine and Atmospheric Science

Language

en_US

Source

This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.

Identifier

http://hdl.handle.net/11401/78263

Publisher

The Graduate School, Stony Brook University: Stony Brook, NY.

Format

application/pdf

Abstract

This study examines the influence of aerosol model configuration, prescribed and prognostic models, on the formation of tropical cyclones (TCs) in the North Atlantic Ocean in the Community Atmosphere Model version 5 (CAM5). The impact of the aerosol parameterization is examined by investigating storm track density, genesis density, potential intensity, and genesis potential index. Landfalling and land impacting TCs are also compared between the two model simulations. This work shows that both CAM5 configurations simulate reduced storm frequency when compared to observations and that differences in TC climatology between the model configurations can be explained by differences in the large-scale environment. Landfall frequency along the East Coast of the U.S. decreases with the decrease in TC formation as expected. The analysis shows that the prognostic aerosol parameterization scheme in CAM5 reasonably captures the observed interannual variability in tropical cyclones and aerosols (i.e. | dust) in the North Atlantic, while the prescribed configuration (climatology) does not. The correlation between dust and TCs in observations (i.e. | reanalysis and satellite datasets) is shown to be negatively correlated (r=-0.43 and r=-0.49, respectively) and this relationship was also found for the CAM5 prognostic aerosol configuration (r=-0.34), despite an overall decrease in the frequency of TCs. Both models underrepresent the overall precipitation and extreme precipitation events that results from landfalling TCs in the region compared to observations. This indicates that in order to accurately replicate certain aspects of TC interannual variability, the aerosol configuration within CAM5 needs to account for the appropriate dust variability. | 43 pages

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