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| Titel |
Modeled precipitation response to realistic land use/cover changes from 1980 to 2000 over Eastern China |
| VerfasserIn |
Hu Yang, Zhang Xue-Zhen, Gong Dao-Yi, Mao Rui |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250090552
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| Publikation (Nr.) |
 EGU/EGU2014-4802.pdf |
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| Zusammenfassung |
| Land use/cover changes are important anthropogenic factors of climate change.
In this study, the precipitation response to land use/cover changes from 1980 to
2000 over Eastern China is simulated using the Weather Research and Forecasting
(WRF) coupled with Noah-MP land surface model. We performed two 21-year
(1980-2000) experiments using exactly the same settings except for the underlying land
use/cover. One experiment used land use/cover for 1980s and the other used land
use/cover for 2000s. To exclude the effects of unusual climate background, we selected
7 normal summer monsoon years. Through comparing the mean simulations of
the 7 years from two experiments, we revealed out the effects of land use/cover
changes.
Eastern China had undergone significant anthropogenic land cover changes such as
deforestation and agricultural expansion in the last two decades of 20th century.
Conversions from grassland and forest to cropland increased the surface albedo and
reduced surface net solar radiation. As the response, both of the surface sensible
heat flux and latent heat flux decreased in the southern part of China. The local
air temperature therefore has little changed. However, surface sensible heat flux
decreased largely while latent heat flux decreased slightly in the northern part of
China. The local air temperature therefore has decreased obviously. This cooling
effect may decrease the temperature gradients between land and ocean and therefore
would weaken the summer monsoon over Eastern China. As a consequence, the
rainfall over lower reaches of the Yangtze River decreased while the rainfall over
Southern China increased. Besides, the cooling effect enhanced the subsidence over
the northern part of Eastern China and may be primarily responsible for the low
pressure and cyclonic anomalies over Korean Peninsula through upstream effects.
Circulation anomalies could change the moisture transport and then influence rainfall
and atmospheric heating, which may enhance the cooling and form the feedback
mechanism. As a result, rainfall increased over Northeastern China and Korean Peninsula. |
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