Relationship between lifecycle of tropical cyclone and lightning frequency an insight from a numerical simulation
Abstract
The relationship between lifecycle of tropical cyclone (TC) and lightning frequency was investigated using a meteorological library called Scalable Computing for Advanced Library and Environment (SCALE; Sato et al. 2015, Nishizawa et al. 2015) coupled with an explicit lightning model (Sato et al., in revision). To investigate the relationship, an idealized experiment covering from initial to steady state (SS) of TC based on Miyamoto and Takemi (2013) was conducted. The results of the simulation indicate that the lightning frequency is maximum before rapid intensification (RI) of TC, which supports previous observational studies (e.g., DeMaria et al., 2012; Stevenson et al., 2016). The frequency of lightning decreases after RI and it keeps small until the TC reaches SS. Our analyses indicate that the dependency of the lightning frequency upon the TC's lifecycle is originated from the difference in the mechanism triggering convective clouds. Before the RI, the convective clouds are mainly generated by consuming convective available potential energy (CAPE). In such case, hydrometeors are effectively transported upward, and the charge split and the lightning frequently occur. After the RI, in contrast, the secondary circulation of TC becomes clear and convective clouds are mainly triggered by the updraft along with the secondary circulation. In this case, the positively charged ice particles and snow constructing anvil are transported outside of the TC by the secondary circulation, which resulted in the weak charge density in inner core region and small frequency of lightning. Our analyses also indicate that the timing of the maximum lightning frequency is corresponding to the pre-conditioning stage of the TC, when the convective clouds generated by consuming CAPE are generated most frequently during TC's lifecycle.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMAE21A..08S
- Keywords:
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- 3304 Atmospheric electricity;
- ATMOSPHERIC PROCESSES;
- 3314 Convective processes;
- ATMOSPHERIC PROCESSES;
- 3324 Lightning;
- ATMOSPHERIC PROCESSES;
- 0694 Instruments and techniques;
- ELECTROMAGNETICS