Projected increase of the East Asian summer monsoon ( Meiyu ) in Taiwan by climate models with variable performance

Journal Article · 13 February 2020 · Meteorological Applications

DOI: https://doi.org/10.1002/met.1886 · OSTI ID:1599651

Tung, Yu‐Shiang  ^[1]; Wang, S. ‐Y. Simon ^[2]; Chu, Jung‐Lien ^[1]; Wu, Chi‐Hua ^[3]; Chen, Yung‐Ming ^[1]; Cheng, Chao‐Tzuen ^[1]; Lin, Lee‐Yaw ^[1]

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1. National Science and Technology Center for Disaster Reduction Taipei Taiwan
2. Department of Plants, Soils and Climate Utah State University Logan UT
3. Research Center for Environmental Changes Academia Sinica Taipei Taiwan

Abstract The active phase of the East Asian summer monsoon (EASM) in Taiwan during May and June, known as Meiyu , produces substantial precipitation for water uses in all sectors of society. Following a companion study that analysed the historical increase in the Meiyu precipitation, the present study conducted model evaluation and diagnosis based on the EASM lifecycle over Taiwan. Higher and lower skill groups were identified from 17 Couple Model Intercomparison Project Phase 5 (CMIP5) models, with five models in each group. Despite the difference in model performance, both groups projected a substantial increase in the Meiyu precipitation over Taiwan. In the higher skill group, weak circulation changes and reduced low‐level convergence point to a synoptically unfavourable condition for precipitation. In the lower skill group, intensified low‐level southwesterly winds associated with a deepened upper level trough enhance moisture pooling. Thus, the projected increase in Meiyu precipitation will likely occur through the combined effects of (1) the extension of a strengthened North Pacific anticyclone enhancing southwesterlies; and (2) more systematically, the Clausius–Clapeyron relationship that increases precipitation intensity in a warmer climate. The overall increase in the Meiyu precipitation projected by climate models of variable performance supports the observed tendency toward more intense rainfall in Taiwan and puts its early June 2017 extreme precipitation events into perspective.

• Sponsoring Organization: USDOE
• OSTI ID: 1599651
• Alternate ID(s): OSTI ID: 1599652
• Journal Information: Meteorological Applications, Journal Name: Meteorological Applications Vol. 27 Journal Issue: 1; ISSN 1350-4827
• Publisher: Wiley Blackwell (John Wiley & Sons)Copyright Statement
• Country of Publication: United Kingdom
• Language: English