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

Journal Article
Climate Dynamics, 2023
Yongkang Xue, Ismaila Diallo, Aaron A. Boone, Yang Zhang, Xubin Zeng, William K. M. Lau, J. David Neelin, Tandong Yao, Qi Tang, Tomonori Sato, Myung-Seo Koo, Frederic Vitart, Constantin Ardilouze, Subodh K. Saha, Stefano Materia, Zhaohui Lin, Yuhei Takaya, Jing Yang, Tetsu Nakamura, Xin Qi, Yi Qin, Paulo Nobre, Retish Senan, Hailan Wang, Hongliang Zhang, Mei Zhao, Hara Prasad Nayak, Yan Pan, Xiaoduo Pan, Jinming Feng, Chunxiang Shi, Shaocheng Xie, Michael A. Brunke, Qing Bao, Marcus Jorge Bottino, Tianyi Fan, Songyou Hong, Yanluan Lin, Daniele Peano, Yanling Zhan, Carlos R. Mechoso, Xuejuan Ren, Gianpaolo Balsamo, Sin Chan Chou, Patricia de Rosnay, Peter J. van Oevelen, Daniel Klocke, Michael Ek, Xin Li, Weidong Guo, Yuejian Zhu, Jianping Tang, Xin-Zhong Liang, Yun Qian, Ping Zhao
AbstractThe 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.