Prominent Midlatitude Circulation Signature in High Asia's Surface Climate During Monsoon
Prominent Midlatitude Circulation Signature in High Asia's Surface Climate During Monsoon
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DOI：
10.1002/2017jd027414
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发表时间：
2017-12
期刊：
影响因子：
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通讯作者：
T. Mölg;F. Maussion;E. Collier;J. Chiang;D. Scherer
中科院分区：
文献类型：
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作者：
T. Mölg;F. Maussion;E. Collier;J. Chiang;D. Scherer
近几十年来，高亚洲经历了强烈的环境变化，这在冰川、湖泊、树木年轮和植被的记录中显而易见。然而，对气候驱动因素的多尺度理解仍然不完整。特别是，很少有系统的评估评估到什么程度，如果在所有，中纬度西风环流修改当地的地面气候达到印度夏季风。本文表明，对流层上部西风带的南移通过两种显著的偶极子型对核心季风季节（7 - 9月）的气候变率有显著贡献：高亚洲西部的冷却与东部的变暖形成对比，而东部和西北部的潮湿异常与西南边缘的干燥沿着。环流异常有助于理解偶极子，并与西风波列和南亚高压的变化相吻合，这对气团平流和当地能量收支产生了影响。变化与中纬度气候动力学的一个成熟指数的关系使未来对气候代用指标的研究能够包括一个解释环境变化的新假设。
High Asia has experienced strong environmental changes in recent decades, as evident in records of glaciers, lakes, tree rings, and vegetation. The multiscale understanding of the climatic drivers, however, is still incomplete. In particular, few systematic assessments have evaluated to what degree, if at all, the midlatitude westerly circulation modifies local surface climates in the reach of the Indian Summer Monsoon. This paper shows that a southward shift of the upper‐tropospheric westerlies contributes significantly to climate variability in the core monsoon season (July–September) by two prominent dipole patterns at the surface: cooling in the west of High Asia contrasts with warming in the east, while moist anomalies in the east and northwest occur with drying along the southwestern margins. Circulation anomalies help to understand the dipoles and coincide with shifts in both the westerly wave train and the South Asian High, which imprint on air mass advection and local energy budgets. The relation of the variabilities to a well‐established index of midlatitude climate dynamics allows future research on climate proxies to include a fresh hypothesis for the interpretation of environmental changes.