Remote effects of Tibetan Plateau spring land temperature on global subseasonal to seasonal precipitation prediction and comparison with effects of sea surface temperature: the GEWEX/LS4P Phase I experiment
Xue, Yongkang ; Diallo, Ismaila ; Boone, Aaron A. ; Zhang, Yang ; Zeng, Xubin ; Lau, William K. M. ; Neelin, J. David ; Yao, Tandong ; Tang, Qi ; Sato, Tomonori ; Koo, Myung-Seo ; Vitart, Frederic ; Ardilouze, Constantin ; Saha, Subodh K. ; Materia, Stefano ; Lin, Zhaohui ; Takaya, Yuhei ; Yang, Jing ; Nakamura, Tetsu ; Qi, Xin ; Qin, Yi ; Nobre, Paulo ; Senan, Retish ; Wang, Hailan ; Zhang, Hongliang ; Zhao, Mei ; Nayak, Hara Prasad ; Pan, Yan ; Pan, Xiaoduo ; Feng, Jinming ; Shi, Chunxiang ; Xie, Shaocheng ; Brunke, Michael A. ; Bao, Qing ; Bottino, Marcus Jorge ; Fan, Tianyi ; Hong, Songyou ; Lin, Yanluan ; Peano, Daniele ; Zhan, Yanling ; Mechoso, Carlos R. ; Ren, Xuejuan ; Balsamo, Gianpaolo ; Chou, Sin Chan ; de Rosnay, Patricia ; van Oevelen, Peter J. ; Klocke, Daniel ; Ek, Michael ; Li, Xin ; Guo, Weidong ; Zhu, Yuejian ; Tang, Jianping ; Liang, Xin-Zhong ; Qian, Yun ; Zhao, Ping
The prediction skill for precipitation anomalies in late spring and summer months-a significant component of extreme climate events-has remained stubbornly low for years. This paper presents a new idea that utilizes information on boreal spring land surface temperature/subsurface temperature (LST/SUBT) anomalies over the Tibetan Plateau (TP) to improve prediction of subsequent summer droughts/floods over several regions over the world, East Asia and North America in particular. The work was performed in the framework of the GEWEX/LS4P Phase I (LS4P-I) experiment, which focused on whether the TP LST/SUBT provides an additional source for subseasonal-to-seasonal (S2S) predictability. The summer 2003, when there were severe drought/flood over the southern/northern part of the Yangtze River basin, respectively, has been selected as the focus case. With the newly developed LST/SUBT initialization method, the observed surface temperature anomaly over the TP has been partially produced by the LS4P-I model ensemble mean, and 8 hotspot regions in the world were identified where June precipitation is significantly associated with anomalies of May TP land temperature. Consideration of the TP LST/SUBT effect has produced about 25-50% of observed precipitation anomalies in most hotspot regions. The multiple models have shown more consistency in the hotspot regions along the Tibetan Plateau-Rocky Mountain Circumglobal (TRC) wave train. The mechanisms for the LST/SUBT effect on the 2003 drought over the southern part of the Yangtze River Basin are discussed. For comparison, the global SST effect has also been tested and 6 regions with significant SST effects were identified in the 2003 case, explaining about 25-50% of precipitation anomalies over most of these regions. This study suggests that the TP LST/SUBT effect is a first-order source of S2S precipitation predictability, and hence it is comparable to that of the SST effect. With the completion of the LS4P-I, the LS4P-II has been launched and the LS4P-II protocol is briefly presented.</p>
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