副热带急流强度和赤道QBO对平流层突然增温的影响

THE INFLUENCE OF THE SUBTROPICAL JET STRENGTH AND EQUATORIAL QBO ON SUDDEN STRATOSPHERIC WARMINGS

使用一个全球原始方程半谱模式模拟了副热带急流强度和赤道准两年振荡（ＱＢＯ）对平流层突然增温（ＳＳＷ）的影响．结果指出：副热带急流强度对ＳＳＷ有明显影响，副热带急流越强，ＳＳＷ发展越快，极区最大增温区的高度越低；赤道ＱＢＯ不同相位零风线的南北位移对ＳＳＷ没有明显影响；ＱＢＯ东风相位时副热带急流更强，而ＱＢＯ西风相位时副热带急流较弱的观测事实，可能是大的中冬ＳＳＷ更容易发生在ＱＢＯ东风相位的主要原因．

A primitive equation semi-spectral model is used to simulate the subtropical jet strength and the equatorical QBO's influence on the sudden stratosphenc warmings(SSW). The results show that the influence of subtropical jet strength on the SSW is obvious and the stronger the subtropical jet was,the faster the stratospheric warmings would occur and the lower the height of warmings center would be.The displacement of the zero wind line of QBO has no apparent effect on the SSW.The obsevation facts that the subtropical jet is stronger during the easterly phase of QBO than during the westerly phase of QBO may be the primary cause of the phenomenon that the major midwinter stratospheric warmings cocur more readily during the easterly phase of the QBO.