Rlationship between the Southern Hemisphere upper troposphere zonal wind variability and the East Asian summer monsoon was studied. The mean zonal wind difference in 150 hPa between 60°S and 30°S is defined ...Rlationship between the Southern Hemisphere upper troposphere zonal wind variability and the East Asian summer monsoon was studied. The mean zonal wind difference in 150 hPa between 60°S and 30°S is defined as an index (ISH). The re- search reveals that ISH is negatively correlated with the East Asian summer monsoon (EASM) circulation in the interannual scale. It is also suggested that the meridional teleconnection in the zonal wind field, with the main part in Eastern Hemisphere, from mid-and- high latitudes in the Southern Hemisphere to the tropical region is responsible for the ISH-EASM link- age. The teleconnection may result in changes of the wind fields and pressure system changes causing variability of the East Asian monsoon. In addition, the anomalous teleconnection pattern in Eurasia is likely to be another mechanism. ISH and EASM circulation are found to have both simultaneous and lag correla- tions, thus, the relationship has implications for sea- sonal climate prediction over East Asia.展开更多
Zonal wind anomaly over the equatorial west- ern Pacific plays an important role in the occurrence of ENSO. The mechanism to produce zonal wind anomaly over the equatorial western Pacific is studied in this paper. It ...Zonal wind anomaly over the equatorial west- ern Pacific plays an important role in the occurrence of ENSO. The mechanism to produce zonal wind anomaly over the equatorial western Pacific is studied in this paper. It is shown clearly that zonal wind anomaly over the equatorial western Pacific is closely related to the anomaly of East- Asian winter monsoon. Anomalous strong (weak) East-Asian winter monsoon can excite not only the westerly (easterly) anomaly over the equatorial western Pacific but also a cyc- lonic (an anticyclonic) circulation over the east of the Philip- pines. The above anomalous circulation results from dy- namical impacts of anomalous pressure pattern due to the East-Asian winter monsoon. Because there is westward (eastward) pressure gradient over the equatorial western Pacific, i.e. there is ?? xp <0(> 0), during strong (weak) East-Asian winter monsoon.展开更多
基金This work was jointly supported by the Chinese Academy of Sciences(Grant No.KZCX3-SW-221)the National Natural Science Foundation of China(Grant No.40620130113)International Partnership Project of the Chinese Academy of Sciences.
文摘Rlationship between the Southern Hemisphere upper troposphere zonal wind variability and the East Asian summer monsoon was studied. The mean zonal wind difference in 150 hPa between 60°S and 30°S is defined as an index (ISH). The re- search reveals that ISH is negatively correlated with the East Asian summer monsoon (EASM) circulation in the interannual scale. It is also suggested that the meridional teleconnection in the zonal wind field, with the main part in Eastern Hemisphere, from mid-and- high latitudes in the Southern Hemisphere to the tropical region is responsible for the ISH-EASM link- age. The teleconnection may result in changes of the wind fields and pressure system changes causing variability of the East Asian monsoon. In addition, the anomalous teleconnection pattern in Eurasia is likely to be another mechanism. ISH and EASM circulation are found to have both simultaneous and lag correla- tions, thus, the relationship has implications for sea- sonal climate prediction over East Asia.
基金supported by the National Natural Science Foundation of China(Grant No.40233033)the Blazing New Trails Program of the Chinese Academy of Sciences(Grant No.ZKCX3-SW-226).
文摘Zonal wind anomaly over the equatorial west- ern Pacific plays an important role in the occurrence of ENSO. The mechanism to produce zonal wind anomaly over the equatorial western Pacific is studied in this paper. It is shown clearly that zonal wind anomaly over the equatorial western Pacific is closely related to the anomaly of East- Asian winter monsoon. Anomalous strong (weak) East-Asian winter monsoon can excite not only the westerly (easterly) anomaly over the equatorial western Pacific but also a cyc- lonic (an anticyclonic) circulation over the east of the Philip- pines. The above anomalous circulation results from dy- namical impacts of anomalous pressure pattern due to the East-Asian winter monsoon. Because there is westward (eastward) pressure gradient over the equatorial western Pacific, i.e. there is ?? xp <0(> 0), during strong (weak) East-Asian winter monsoon.
