Advances in Earth Science ›› 2009, Vol. 24 ›› Issue (3): 338-348. doi: 10.11867/j.issn.1001-8166.2009.03.0338

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Stratospheric Oscillation and Stratosphere-Troposphere Coupling in 2007/2008 Winter

Xiang Chunyi 1,2, He Jinhai 1, Ren Rongcai 2   

  1. 1.Department of Atmospheric Science Nanjing University of Information Science and Technology, Nanjing 210044,China;
    2.State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Science, Beijing 100029,China
  • Received:2009-01-19 Revised:2009-02-20 Online:2009-03-10 Published:2009-03-10

Xiang Chunyi, He Jinhai, Ren Rongcai. Stratospheric Oscillation and Stratosphere-Troposphere Coupling in 2007/2008 Winter[J]. Advances in Earth Science, 2009, 24(3): 338-348.

      Based on the NCEP/NCAR reanalysis data, the features of the stratospheric oscillations and the stratosphere-troposphere coupling in 2007/2008 winter were analyzed. It was found that the stratospheric polar vortex was persistently stronger during this winter. It was elongated and eccentrically developed along Eastern Asia and Atlantic, and shrank along Western-Euro and Mediterranean since the early December, 2007. Consequently, the “one ridge and one trough” pattern first appeared in the high stratosphere in the eastern hemisphere. These anomalous stratospheric signals were then propagated systematically downward; it took about 15~20 days for them to advance from 10 hPa to lower tropospheric levels. Following the propagated signals from upper levels, the corresponding “high-in-west and low-in-east” pattern in the high latitude, and “high-in-east and low-in-west” pattern in the subtropics at 500 hPa were clearly seen. They are closely related with the anomalous centers, such as the Siberia blocking high, Okhotsk low, Western-Pacific-Subtropical-High and lows in the mid-western part of Euro-Asia continent, which together favored the formation of sever snow in the south China. Further investigations indicated that there also existed poleward propagations of the stratospheric circulation anomalies that were found generated in the deep tropics. The stratospheric circulation anomalies responsible to the occurrence of the stratospheric polar vortex oscillations in January of 2008 could be tracked back to as early as the middle October in 2007. Accompanying the poleward propagation, the stratospheric anomaly signals were seen moving eastward simultaneously. In all, results from this work are strongly suggesting that our potential ability in predicting the climatic tendency in the troposphere could be significantly improved by catching with the leading stratospheric signals effectively.

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