チベット高原の降雨と北大西洋気候パターンの関係(Scientists Discover North Atlantic Climate Pattern Linked to Qinghai-Tibet Plateau Rainfall Swings)

2025-09-19 中国科学院(CAS)

中国科学院大気物理研究所の研究チームは、北大西洋の海面水温の異常な双極子パターンが、青海‐チベット高原北部の夏季降水量変動を左右することを発見しました。これは大気のテレコネクションを通じて伝わり、ロスビー波がヨーロッパから中央アジアへ東進し、崑崙山脈周辺で反気旋循環と異常な南風を形成、水蒸気輸送を強化して降水を増減させます。この成果は遠隔の海洋・大気相互作用と地域の水文過程を結びつけ、気候リスク管理の向上に貢献する可能性があります。

<関連情報>

北大西洋海面水温ダイポールがチベット高原北部における夏季降水量の年々変動を調節する North Atlantic SST dipole modulates the interannual variability of summer precipitation over northern Tibetan Plateau

Shijie Tang,Tianjun Zhou,Jie Jiang & Wanheng Ye
Climate Dynamics  Published:12 August 2025
DOI:https://doi.org/10.1007/s00382-025-07823-4

チベット高原の降雨と北大西洋気候パターンの関係(Scientists Discover North Atlantic Climate Pattern Linked to Qinghai-Tibet Plateau Rainfall Swings)

Abstract

Along the northern Tibetan Plateau, the Kunlun Mountains are a principal hydrological regulator for the Tarim Basin, with precipitation variability shaping water availability and downstream geological hazards. However, the factors and the underlying physical mechanisms driving the interannual variability of precipitation remain poorly understood. Here, we investigate the interannual variability of summer precipitation in the Kunlun Mountains and its surrounding (KMS) region by combining observation and reanalysis datasets. The results show that summer precipitation in the KMS region exhibits significant interannual variability, accounting for 77% of total summer precipitation variability. It features a dominant 3-year cycle, with variability decreasing from southeast to northwest and a maximum magnitude of 52.8 mm/a. The interannual variability of summer precipitation in the KMS region is driven by an anomalous North Atlantic sea surface temperature dipole, which generates a downstream-propagating Rossby wave and induces an anomalous cyclonic circulation in the west of the KMS region. This circulation anomaly further induces anomalous meridional winds over the KMS region, enhancing horizontal water vapor convergence and dynamically modulating regional precipitation. Our findings provide new insights into the mechanisms driving precipitation variability in the KMS region, contributing to broader efforts in climate adaptation and sustainable development in arid and semi-arid regions.

1702地球物理及び地球化学
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