夏季青藏高原上空热力异常与其上下游大气环流联系的研究进展

Advances in the study of linkage between the Tibetan Plateau thermal anomaly and atmospheric circulations over its upstream and downstream regions

围绕夏季青藏高原热力异常与其上、下游大气环流在年际尺度变化上的联系,对最新的研究成果做了简要介绍。通过观测资料分析与数值试验,指出在年际尺度上夏季青藏高原热力异常与同期亚洲-太平洋涛动(APO)具有显著且稳定的联系,前者可能通过调节亚洲和中东太平洋热带外大尺度垂直环流异常影响后者。另外,夏季青藏高原热力异常对高原上空及更大范围上对流层温度的年际变化也有一定贡献,进而通过对上游大尺度环流的调节作用影响到同期西非萨赫勒地区的降水。夏季青藏高原热力异常只是导致其上、下游大气环流年际变化的一个原因,其他影响效应尚需进一步探讨。

With respect to the relationship between thermal anomaly over the Tibetan Plateau(TP) and atmospheric circulation upstream and downstream of the TP on interannual timescale, the present paper briefly summarizes the latest research. Through observational analyses and numerical experiments, it is revealed that on the interannual timescale, the TP thermal anomaly is significantly and steadily correlated with the Asian-Pacific Oscillation(APO) in the summer. This relationship is likely due to the impact of the TP thermal anomaly on the APO via regulating the anomalous vertical circulation cell over the extratropical Asia and eastern-central Pacific. In addition, the TP thermal anomaly in the summer may contribute to interannual variability of tropospheric temperature over the TP and its adjacent area and associated large-scale circulation in the upstream, which subsequently affect precipitation over Sahel in the West African monsoon region. The TP thermal anomaly is only one of the factors that affect interannual variation of the atmospheric circulation upstream and downstream of the TP, and influences of other factors need further investigation in the future.