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Title: Understanding the characteristics of microphysical processes in the rapid intensity changes of tropical cyclones over the Bay of Bengal

This study aimed to understand the microphysical processes that affect rapid intensity changes of tropical cyclones (TCs) over the Bay of Bengal (BoB). Four representative TCs were simulated using the Weather Research and Forecasting model with storm tracking nested configuration (at 9‐km and 3‐km resolution). Results indicate that the inner‐core heating strongly correlated (r > 0.85) with the precipitated compared to non‐precipitated hydrometeors. Furthermore, the vertical distribution of hydrometeors and heating is dependent on inner‐core updrafts and relative humidity. A novel composite analysis of microphysical processes indicates that the warmer (2 K) inner core is close to saturation (>90%) with excess water vapor (>2–3 × 10−3 kg·kg−1), which enhances the latent heat release (LHR) through condensation below the freezing level during the rapid intensification (RI) onset. In addition, during RI, strong updrafts transport the water vapor (>2 × 10−3 kg·kg−1) and cloud liquid water (2.5 × 10−4 kg·kg−1) to above freezing level, and enhance the LHR because of deposition and freezing respectively. The increased precipitating particles in the saturated inner core also enhance LHR. The symmetric convection structured by the atmospheric moisture causes the formation of prolonged RI episodes, as seen in TCPhailin. During rapid weakening (RW), asymmetric and relatively fewer hydrometeors are evident, along with the presence of weak updrafts and strong shear. The dry‐air intrusion into the inner core also causes the cooling processes (evaporation and sublimation). The enhancement or reduction of moist static energy and potential vorticity is associated with increased or reduced LHR in the TC rapid intensity changes.

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Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Quarterly Journal of the Royal Meteorological Society
Page Range / eLocation ID:
p. 3715-3729
Medium: X
Sponsoring Org:
National Science Foundation
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