The first decadal leading mode of East Asian summer rainfall(EASR) is characterized by rainfall anomalies along the East Asian subtropical rain belt. This study focuses on the second decadal leading mode(2DLM), accoun...The first decadal leading mode of East Asian summer rainfall(EASR) is characterized by rainfall anomalies along the East Asian subtropical rain belt. This study focuses on the second decadal leading mode(2DLM), accounting for 17.3% of rainfall decadal variance, as distinct from the other two neighboring modes of EAMR, based on the state-of-the-art in-situ rainfall data.This mode is characterized by a South-China-wet–HuaiheRiver-dry pattern, and is dominated by a quasi-30-yr period. Further analysis reveals the 2DLM corresponds to an enhanced lower-level monsoon jet, an eastward extension of the western North Pacific subtropical high, and a weakened East Asian upper-level westerly jet flow. The Tibetan Plateau surface temperature and Pacific Decadal Oscillation(PDO) are closely linked with the 2DLM. The regressed SST pattern indicates the PDO-like pattern of sea surface temperature anomalies may have a teleconnection relationship with the 2DLM of EASR.展开更多
The Tibetan Plateau is a key factor for the pattern of the general circulation of the atmosphere (GCA) in eastern Asia. The pattern of the GCA after the uplift of the plateau is well known, while the pattern of the GC...The Tibetan Plateau is a key factor for the pattern of the general circulation of the atmosphere (GCA) in eastern Asia. The pattern of the GCA after the uplift of the plateau is well known, while the pattern of the GCA before the uplift of the plateau is lack of direct evidences. Based on the knowability of desert, a section recording wind directions across the Cretaceous northern hemisphere mid-low latitude desert belt is measured and the pattern of the GCA in the Cretaceous is revealed. The result shows that the eastern Asia was really controlled by the planetary circulation before the uplift of the plateau, i.e. westerlies in the north and northeast trades in the south. The convert belt between westerlies and trades had drifted northwards and southwards. The possibility of existence of paleo-monsoon is also dealt with and a possibly imposed paleo-monsoon is suggested.展开更多
基金supported by the National Basic Research Program (973 Program, Grant No. 2012CB417203)the R&D Special Fund for Public Welfare Industry (Meteorology) (Grant No. GYHY201406001)+1 种基金Strategic Leading Science Projects of the Chinese Academy of Sciences (Grant No. XDA11010402)the National National Science Foundation of China (Grant Nos. 91337110 and 40805038)
文摘The first decadal leading mode of East Asian summer rainfall(EASR) is characterized by rainfall anomalies along the East Asian subtropical rain belt. This study focuses on the second decadal leading mode(2DLM), accounting for 17.3% of rainfall decadal variance, as distinct from the other two neighboring modes of EAMR, based on the state-of-the-art in-situ rainfall data.This mode is characterized by a South-China-wet–HuaiheRiver-dry pattern, and is dominated by a quasi-30-yr period. Further analysis reveals the 2DLM corresponds to an enhanced lower-level monsoon jet, an eastward extension of the western North Pacific subtropical high, and a weakened East Asian upper-level westerly jet flow. The Tibetan Plateau surface temperature and Pacific Decadal Oscillation(PDO) are closely linked with the 2DLM. The regressed SST pattern indicates the PDO-like pattern of sea surface temperature anomalies may have a teleconnection relationship with the 2DLM of EASR.
基金the National Natural Science Foundation of China (Grant No. 49572113).
文摘The Tibetan Plateau is a key factor for the pattern of the general circulation of the atmosphere (GCA) in eastern Asia. The pattern of the GCA after the uplift of the plateau is well known, while the pattern of the GCA before the uplift of the plateau is lack of direct evidences. Based on the knowability of desert, a section recording wind directions across the Cretaceous northern hemisphere mid-low latitude desert belt is measured and the pattern of the GCA in the Cretaceous is revealed. The result shows that the eastern Asia was really controlled by the planetary circulation before the uplift of the plateau, i.e. westerlies in the north and northeast trades in the south. The convert belt between westerlies and trades had drifted northwards and southwards. The possibility of existence of paleo-monsoon is also dealt with and a possibly imposed paleo-monsoon is suggested.
