Are precipitation anomalies associated with aerosol variations over eastern China?
In eastern China (EC), the strong anthropogenic emissions deteriorate the atmospheric environment, building a south–north zonal distribution of high aerosols harbored by the upstream Tibetan and Loess plateaus in China. This study climatologically analyzed the interannual variability in precipit...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-06-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/17/8011/2017/acp-17-8011-2017.pdf |
| Summary: | In eastern China (EC), the strong anthropogenic emissions
deteriorate the atmospheric environment, building a south–north zonal
distribution of high aerosols harbored by the upstream Tibetan and Loess
plateaus in China. This study climatologically analyzed the interannual
variability in precipitation with different intensities in association with
aerosol variations over the EC region from 1961 to 2010 by using
precipitation and visibility data from more than 50 years and aircraft and
surface aerosol data from recent years in China, and the impacts of aerosol
variations on interannual variability in the intensity of
precipitation events and their physical causes are investigated. We found
that the frequency of light rain has significantly decreased and the occurrence
of rainstorms, especially severe rainstorms, has significantly increased
over recent decades. The extreme precipitation events presented an
interannual variability pattern similar to that of the frequent haze events over EC.
Accompanied by the frequent haze events in EC, light rain frequency
significantly decreased and extremely heavy precipitation events have
occurred more frequently. During the 1980s, the regional precipitation trends
in EC showed an obvious transform from more light rain to more extreme
rainstorms. The running correlation analysis of interdecadal variation
further verified that the correlation between the increasing aerosols and
frequencies of abnormal precipitation events tended to be more significant in
EC. The correlation between atmospheric visibility and low cloud amounts,
which are both closely related to aerosol concentrations, was positive in the north and negative in the south, and the
spatial distribution of the variability in regional rainstorm frequency was
positive in the south and negative in the north. After the 1990s, the visibility
in summer season deteriorated more remarkably, light rain frequency
decreased noticeably, and rainstorms and extraordinarily heavy rainfall
occurred more frequently. There were significant differences in the
interdecadal variation trends in light rain and rainstorm events between the
highly aerosol-polluted area in EC and the relatively clean area on the
western plateaus of China. The aircraft measurements over EC confirmed
that the diameters of cloud droplets decreased under high aerosol
concentration conditions, thereby inhibiting weak precipitation process. |
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| ISSN: | 1680-7316 1680-7324 |