| Autor: |
Han, Yizhe, Jiang, Dabang, Si, Dong, Ma, Yaoming, Ma, Weiqiang, Hu, Wei |
| Předmět: |
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| Zdroj: |
Climate Dynamics; May2024, Vol. 62 Issue 5, p4253-4266, 14p |
| Abstrakt: |
Previous studies have emphasized the significant influence of the atmospheric heat source of the Tibetan Plateau (TPHS) on the weather and climate in East Asia, but the causes and mechanisms of the TPHS variations remain unclear. In this study, the physical linkage between the winter northern Eurasian snow depth and early summer (May and June) TPHS during 1950–2019 is investigated. Our results indicate that excessive winter northern Eurasian snow can decrease the early summer TPHS through a delayed hydrological effect. In winter, excessive northern Eurasian snow depths lead to more snowmelt and wetter local soil in early summer. The wetter soil not only reduces the surface temperatures in northern Eurasia but also cools the atmosphere in the middle and upper troposphere. This cooling enhances the meridional temperature gradient between northern and southern Eurasia, which reinforces the westerly jet stream at mid-latitudes. The strong westerly jet stream enhances the sensible heat flux over the Tibetan Plateau (TP) by increasing the near-surface wind speed. Moreover, the enhanced meridional temperature gradient generates an anticyclonic and high-pressure anomaly over the southwestern side of the TP, thus decreasing the latent heat release over the TP. Because early summer marks the beginning of the rainy season on the TP, the TPHS in early summer is dominated by latent heat released by precipitation, which means that the wetter soil caused by the excessive winter snow depth in northern Eurasia eventually weakens the TPHS in early summer. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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