Radiative Feedback Accelerates Pre-TC Mid-level Moist Vortex
Abstract
Radiative feedback is important to TC genesis, but the mechanism behind is still unclear. In this study, the authors find that long wave radiative feedback can bring forward TC genesis by accelerating the Pre-TC mid-level moist vortex. Analysis shows that radiative warming anomaly dominates near the vortex center. Typically, a strong warming anomaly from 6-11km is responsible for the acceleration. This anomaly is a cloud radiative effect, which is caused by large concentration of ice-phased particles (in our simulation, snow) near the vortex at high levels. PV perspective is introduced to analyze the acceleration of mid-level vortex. The 6-11km radiative warming anomaly induces more non-convective upward water vapor flux, leading to more microphysics heating above 6km and more cooling below 6km, which enhances diabatic heating gradient and finally increase PV. Real case sensitivity experiments further validate the importance of this mechanism.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A11G..06Y
- Keywords:
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- 0315 Biosphere/atmosphere interactions;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0360 Radiation: transmission and scattering;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3372 Tropical cyclones;
- ATMOSPHERIC PROCESSES;
- 4313 Extreme events;
- NATURAL HAZARDS