1. Earlier Onset and Shortened Meiyu Season During the Last Interglacial Based on Dynamical Downscaling Simulations.
- Author
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Jiang, Nanxuan, Yan, Qing, Wang, Huijun, and Li, Hua
- Subjects
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EARTH'S orbit , *OCEAN waves , *OCEAN temperature , *ATMOSPHERIC circulation , *ROSSBY waves , *TELECONNECTIONS (Climatology) , *WESTERLIES - Abstract
Deciphering the Meiyu behavior during the Last Interglacial (∼127 ka; LIG) may deepen our understanding of drought and flooding events over East Asia in a warmer‐than‐present world induced by Earth's orbit. Based on dynamical downscaling simulations, we suggested a 15‐ and 30‐day earlier onset and retreat of the Meiyu during the LIG relative to preindustrial, respectively, leading to a shortened Meiyu season. Meantime, extreme precipitation in the Meiyu season became stronger and occurred more frequently. Intensified monsoonal circulation, poleward‐located western North Pacific subtropical high, and poleward shift of East Asian westerly jet during the LIG provided favorable moisture conditions for earlier onset and retreat of the Meiyu. The variations of atmospheric circulations were further regulated by the joint effect of the three oceans and diabatic heating over Tibetan Plateau. Our results highlight an important role of Earth's orbit in the Meiyu and imply more flooding events in a warmer world. Plain Language Summary: The record‐breaking Meiyu in 2020 reemphasizes the importance of investigating the evolution of the rainy season in East Asia. This study reveals the response of the Meiyu to changes in the Earth's orbit during the Last Interglacial (LIG, 130–115 ka)—the warmest interglacial of the past 800 ka and a warmer world comparable to the low emission scenarios at the end of the 21st century. The Meiyu season occurred and ended earlier compared with the present day, and the duration was shortened. Additionally, more frequent and intense extreme precipitation events occurred in the Meiyu season during the LIG. The enhanced East Asian summer monsoonal flow, strengthened western North Pacific subtropical high, and poleward shift of the East Asian westerly jet in June provided favorable conditions for the earlier occurrence and termination of the Meiyu during the LIG. Moreover, changes in the sea surface temperature over the three oceans can jointly influence the Meiyu via triggering Kelvin waves, Rossby waves, and teleconnections by atmospheric circulations, with the contribution from the diabatic heating over the Tibetan Plateau. The results of this study help us better understand the evolution of the rainy season over East Asia in a warmer world. Key Points: Earlier onset and shortened duration of Meiyu season during the Last Interglacial (LIG)Stronger and more frequent extreme precipitation events occurred in Meiyu season during the LIGIntensified monsoonal circulation, poleward‐located subtropical high and westerly jets led to changes in Meiyu during the LIG [ABSTRACT FROM AUTHOR]
- Published
- 2022
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