Exploring Dust Impacts on the First Weakening Phase of Hurricane Nadine during HS-3
Abstract
During the 2012 deployment of the NASA Hurricane and Severe Storm Sentinel (HS-3) field campaign, several flights were dedicated to Hurricane Nadine. Hurricane Nadine developed in close proximity to the dust-laden Saharan Air Layer (SAL) and is the fourth longest-lived Atlantic hurricane, experiencing two strengthening and weakening periods during its lifetime. In this study, we use the NASA Goddard Earth Observing System version 5 (GEOS-5) atmospheric general circulation model and assimilation system to simulate impacts of dust during the first weakening phase of Hurricane Nadine. Here, we perform a series of GEOS-5 forecasts initialized from Nadine's peak intensity (September 12, 2012) without aerosol interaction, with direct aerosol interaction (absorption and scattering) with the atmosphere, and with both direct and indirect aerosol interactions using a 2 - moment cloud microphysics scheme that has recently been implemented within GEOS-5. As an added perturbation, we also vary our assumed dust optical properties in our simulations that permit aerosol interaction with the atmosphere. We find that when indirect effects are included, the simulated track best matches the observed track and is relatively insensitive to assumed dust optical properties. However, when only aerosol direct interactions are included, the storm track exhibits sensitivity to dust absorption, as a more absorbing dust impacts winds where the storm is adjacent to Saharan dust. Finally, we find that aerosol impacts on Nadine's simulated track occur shortly after initialization in our simulations that permit direct radiative interaction with the atmosphere, as the simulated track showed little sensitivity when dust optical properties were modified at 24 hour increments past initialization.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A41N..03N
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3359 Radiative processes;
- ATMOSPHERIC PROCESSESDE: 3364 Synoptic-scale meteorology;
- ATMOSPHERIC PROCESSES