Mean and Anomalous 850-hPa Zonal Wind
Time-longitude section of mean (top) and anomalous (bottom) 850-hPa zonal wind averaged between 5N-5S (CDAS/Reanalysis). Contour interval is 2 ms-1. Blue shading and dashed contours indicate easterlies (top) and easterly anomalies (bottom). Anomalies are departures from the 1981-2010 base period monthly means. The data are smoothed temporally using a 3-month running average.