资源环境科技发展态势分析平台

Using 17 years of Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) data, significant responses of GW variances, zonal winds and parameterized GW drag to the Madden-Julian Oscillation (MJO) are identified globally during boreal winter, and their relations are examined. The relative anomalies of GW variances range from -4% (phase 7) to 8% (phase 4) in tropics, and -20% (phase 1) to 20% (phase 5) in the northern polar region (NPR). The anomalies of zonal winds are from -3–3 m/s and -4–8 m/s in tropics and NPR, respectively. The vertical and latitudinal structures of MJO signals in GW, wind and GW drag show coherent patterns. Further analysis implies that in the NPR, the eastward wind leads to westward momentum flux carried by the GWs. This flux leads to westward drag, which drives that of zonal winds and imprint the MJO signal in GWs to the wind.