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| Titel |
Long-term impacts of aerosols on precipitation and lightning over the Pearl River Delta megacity area in China |
| VerfasserIn |
Y. Wang, Q. Wan, W. Meng, F. Liao, H. Tan, R. Zhang |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 11, no. 23 ; Nr. 11, no. 23 (2011-12-12), S.12421-12436 |
| Datensatznummer |
250010257
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| Publikation (Nr.) |
 copernicus.org/acp-11-12421-2011.pdf |
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| Zusammenfassung |
| Seven-year measurements of precipitation, lightning
flashes, and visibility from 2000 to 2006 have been analyzed in the Pearl
River Delta (PRD) region, China, with a focus on the Guangzhou megacity
area. Statistical analysis shows that the occurrence of heavy rainfall
(>25 mm per day) and frequency of lightning strikes are reversely correlated
to visibility during this period. To elucidate the effects of aerosols on
cloud processes, precipitation, and lightning activity, a cloud resolving –
Weather Research and Forecasting (CR-WRF) model with a two-moment bulk
microphysical scheme is employed to simulate a mesoscale convective system
occurring on 28 Match 2009 in the Guangzhou megacity area. The model
predicted evolutions of composite radar reflectivity and accumulated
precipitation are in agreement with measurements from S-band weather radars
and automatic gauge stations. The calculated lightning potential index (LPI)
exhibits temporal and spatial consistence with lightning flashes recorded by
a local lightning detection network. Sensitivity experiments have been
performed to reflect aerosol conditions representative of polluted and clean
cases. The simulations suggest that precipitation and LPI are enhanced by
about 16% and 50%, respectively, under the polluted aerosol condition.
Our results suggest that elevated aerosol loading suppresses light and
moderate precipitation (less than 25 mm per day), but enhances heavy
precipitation. The responses of hydrometeors and latent heat release to
different aerosol loadings reveal the physical mechanism for the
precipitation and lightning enhancement in the Guangzhou megacity area,
showing more efficient mixed phase processes and intensified convection
under the polluted aerosol condition. |
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