 |
| Titel |
Anthropogenic agent implicated as a prime driver of shift in precipitation in eastern China in the late 1970s |
| VerfasserIn |
T. Wang, H. J. Wang, O. H. Otterå, Y. Q. Gao, L. L. Suo, T. Furevik, L. Yu |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 24 ; Nr. 13, no. 24 (2013-12-19), S.12433-12450 |
| Datensatznummer |
250085894
|
| Publikation (Nr.) |
 copernicus.org/acp-13-12433-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| Observation shows that eastern China experienced an interdecadal shift in the
summer precipitation during the second half of the 20th century. The summer
precipitation increased in the middle and lower reaches of the Yangtze River
valley, whereas it decreased in northern China. Here we use a coupled
ocean–atmosphere general circulation model and multi-ensemble simulations to
show that the interdecadal shift is mainly caused by the anthropogenic
forcing. The rapidly increasing greenhouse gases induce a notable Indian
Ocean warming, causing a westward shift of the western Pacific subtropical
high (WPSH) and a southward displacement of the East Asia westerly jet (EAJ)
on an interdecadal timescale, leading to more precipitation in Yangtze River
valley. At the same time the surface cooling effects from the stronger
convection, higher precipitation and rapidly increasing anthropogenic
aerosols contribute to a reduced summer land–sea thermal contrast. Due to the
changes in the WPSH, the EAJ and the land–sea thermal contrast, the East
Asian summer monsoon weakened resulting in drought in northern China.
Consequently, an anomalous precipitation pattern started to emerge over
eastern China in the late 1970s. According to the model, the natural forcing
played an opposite role in regulating the changes in WPSH and EAJ, and
postponed the anthropogenically forced climate changes in eastern China. The
Indian Ocean sea surface temperature is crucial to the response, and acts as
a bridge to link the external forcings and East Asian summer climate together
on a decadal and longer timescales. Our results further highlight the
dominant roles of anthropogenic forcing agents in shaping interdecadal
changes of the East Asian climate during the second half of the 20th century. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|