The strengthening relationship between Eurasian snow cover and December haze days in central North China after the mid-1990s
The haze pollution in December has become increasingly serious over recent decades and imposes damage on society, ecosystems, and human health. In addition to anthropogenic emissions, climate change and variability were conducive to haze in China. In this study, the relationship between the snow...
| Huvudupphovsmän: | , |
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| Materialtyp: | Artikel |
| Språk: | English |
| Publicerad: |
Copernicus Publications
2018-04-01
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| Serie: | Atmospheric Chemistry and Physics |
| Länkar: | https://www.atmos-chem-phys.net/18/4753/2018/acp-18-4753-2018.pdf |
| Sammanfattning: | The haze pollution in December has become increasingly serious over recent
decades and imposes damage on society, ecosystems, and human health. In
addition to anthropogenic emissions, climate change and variability were
conducive to haze in China. In this study, the relationship between the snow
cover over eastern Europe and western Siberia (SC<sub>ES</sub>) and the
number of haze days in December in central North China
was analyzed. This relationship significantly strengthened after the
mid-1990s, which is attributed to the effective connections between the
SC<sub>ES</sub> and the Eurasian atmospheric circulations. During
1998–2016, the SC<sub>ES</sub> significantly influenced the soil moisture
and land surface radiation, and then the combined underlying drivers of
enhanced soil moisture and radiative cooling moved the the East Asia jet
stream northward and induced anomalous, anti-cyclonic circulation over
central North China. Modulated by such atmospheric circulations, the local
lower boundary layer, the decreased surface wind, and the more humid air were
conducive to the worsening dispersion conditions and frequent haze
occurrences. In contrast, from 1979 to 1997, the linkage between the
SC<sub>ES</sub> and soil moisture was negligible. Furthermore, the
correlated radiative cooling was distributed narrowly and far from the key
area of snow cover. The associated atmospheric circulations with the
SC<sub>ES</sub> were not significantly linked with the ventilation
conditions over central North China. Consequently, the relationship between
the SC<sub>ES</sub> and the number of hazy days in central North China was
insignificant before the mid-1990s but has strengthened and has become
significant since then. |
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| ISSN: | 1680-7316 1680-7324 |