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| Titel |
Significant decreasing cloud cover during 1954–2005 due to more clear-sky days and less overcast days in China and its relation to aerosol |
| VerfasserIn |
X. Xia |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 30, no. 3 ; Nr. 30, no. 3 (2012-03-26), S.573-582 |
| Datensatznummer |
250017203
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| Publikation (Nr.) |
 copernicus.org/angeo-30-573-2012.pdf |
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| Zusammenfassung |
| An updated analysis of cloud cover during 1954–2005 in China was performed
using homogeneous cloud cover data from 314 stations. Long-term changes in
frequencies of different cloud cover categories and their contributions to
long-term changes in cloud cover were assessed. Furthermore, aerosol effects
on cloud cover trends were discussed based on comparison of cloud cover
trends in polluted and mildly polluted regions. Frequencies of clear sky
(cloud cover <20%) and overcast days (cloud cover >80%) were
observed to increase by ~2.2 days and decrease by ~3.3 days per
decade, respectively, which accounts for ~80% of cloud cover
reduction. Larger decreasing trends in cloud cover due to larger increase in
clear sky frequency and larger decreases in overcast frequency were observed
at stations with lower aerosol optical depth. There is no significant
difference in trends regarding cloud cover, clear sky frequency, and
overcast frequency between mountain and plain stations. These results are
inconsistent with our expectation that larger decreasing trends in cloud
cover should have been observed in regions with higher aerosol loading where
more aerosols could lead to stronger obscuring effect on ground observation
of cloud cover and stronger radiative effect as compared with the mildly
polluted regions. Aerosol effect on decreasing cloud cover in China appear
not to be supported by this analysis and therefore, further study on this
issue is required. |
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