赤道低平流层纬向风垂直切变与ENSO变率的关系

Relationship between Vertical Shear of Zonal Wind in Equatorial Lower Stratosphere and ENSO Variability

摘要:

利用NCEP/NCAR40a再分析资料研究了赤道低平流层纬向风垂直切变与 ENSO变率间的关系。结果得出,赤道低平流层纬向风的垂直切变呈现明显的准两年振荡,SOI和 Nino3区 SSTA的准两年周期成分与赤道低平流层纬向风垂直切变分别呈现反位相和同位相关系。赤道低平流层西(东)风切变位相时,OLR、1000hPa高度,200hPa高度和温度、850hPa温度等要素的距平分布与其在ElNino(La Nina)时段的分布相似。

Abstract:

Based on the NCEP/NCAR 40-year reanalysis dataset, analysed is the relationship between vertical shear of zonal wind in equatorial lower stratosphere and ENSO variability. It's found that vertical shear of zonal wind in equatorial lower stratosphere bears the features of QBO. The vertical zonal wind shear is opposite to southern oscillation index (SOI) in phase and is in agreement with the SSTA in Nino3 area in phase. During the westerly (easterly) shear phase in equatorial lower stratosphere, the distributions of OLR,1 000 hPa and 200 hPa height fields, 200 hPa and 850 hPa temperature fields are similar to that in El Nino (La Nina) episode.