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| Titel |
A physical-empirical model of the East Asian winter monsoon using Eurasian
snow cover and sea surface temperature |
| VerfasserIn |
Lulu Yu, Zhiwei Wu, Renhe Zhang |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250139293
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| Publikation (Nr.) |
 EGU/EGU2017-2504.pdf |
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| Zusammenfassung |
| Seasonal prediction of the East Asian (EA) winter monsoon (EAWM) is of great
significance yet a challenging issue. In this study, three physical-empirical (PE) seasonal
prediction models for the EAWM are established using three leading modes of the
Eurasian snow cover (ESC), the first leading mode of sea surface temperature (SST)
and the first leading mode of the combination of the ESC and SST in preceding
autumn, respectively. These leading modes are identified by the partial-least square
(PLS) regression. The first PLS (PLS1) mode for the ESC features significantly
anomalous snow cover in Siberia and Tibetan Plateau regions. The ESC second PLS
(PLS2) mode corresponds to large areas of snow cover anomalies in the central
Siberia, whereas the third PLS (PLS3) mode a meridional seesaw pattern of ESC.
The SST PLS1 mode basically exhibits an El Niño-Southern Oscillation (ENSO)
developing phase in equatorial eastern Pacific and significant SST anomalies in North
Atlantic. A strong EAWM tends to emerge in a La Niña year concurrent with cold
SST anomalies in the North Atlantic, and vice versa. After a 35-yr training period
(1967t2001), three PE seasonal prediction models are constructed and the 13-yr
hindcast is performed for the period of 2002t2014, respectively. The PE model
based on combination of the autumn ESC and SST exhibits the best hindcast skill
among the three models, its correlation coefficient between the observation and
the hindcast reaching 0.88. This indicates that this PE model may provide another
practical tool for the EAWM. In addition, the relative contribution of the ESC and
SST is also examined by assessing the hindcast skills of the other two PE models
constructed solely by the ESC or SST. Possible physical mechanisms are also discussed. |
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