Recently, Dr. Zhou Xin, Professor Chen Quanliang and Dr. Li Yang from the School of Atmospheric Sciences published a lecture paper entitled “Does extreme El Niño have a different effect on the stratosphere in boreal winter than its moderate counterpart?” in the international top journal, Journal of Geophysical Research(SCI Journal Division of the Chinese Academy of Sciences: major subject – Geoscience 2; IF=3.44), cooperated with experts from Beijing Normal University and the Institute of Atmospheric Physics of the Chinese Academy of Sciences, in the field of geosciences. And this paper covered the latest research results on the climatic impact of extreme El Niño.

The local air-sea anomaly in the Pacific and the global climatic effects caused by extreme El Niño are more severe than that caused by ordinary El Niño, and in the context of global warming, the extreme El Niño may occur more frequently in the future, and whether its effects on circulation and temperature to the stratosphere are different from ordinary El Niño has not been determined. Using the reanalysis data and the CESM model, the study indicates that El Niño has a lagged effect, about 2 months, on the polar vortex, that is, the polar vortex anomaly signal is strongest after the winter to early spring. This explained why the predecessors’ studies on the response of the winter polar vortex to El Niño were different. On the other hand, the study found that the extreme El Niño’s influences on the temperature and circulation of the mid-high latitude stratosphere are similar to that of the ordinary El Niño, which caused the polar vortex circulation and temperature anomaly to be four times larger than that of the ordinary El Niño.

The study revealed the dynamic mechanism of the extreme El Niño’s influence on the polar vortex. The planetary wave from the troposphere to the stratosphere induced by extreme El Niño is stronger than the ordinary El Niño, resulting in stronger influence on the temperature and circulation of the stratosphere. The results of this study provided new insights into effects of the extreme El Niño on the stratosphere and its physical mechanisms.

Paper information:

Zhou, X., J. P. Li, F. Xie, Q. L. Chen, R. Q. Ding, W. X. Zhang, and Y. Li, 2018: Does Extreme El Nino Have a Different Effect on the Stratosphere in Boreal Winter Than Its Moderate Counterpart? J. Geophys. Res., 123, 3071-3086, doi:10.1175/JCLI-D- 17-0575.1.

This paper can be found in:

https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017JD028064 

Fig.1 Time evolution of the influence of different El Niño intensities on polar vortex.

Fig.2 Uploading planetary wave changes caused by different El Niño intensities.