Maximum Covariance Analysis of the Summertime MJO in the Eastern Paci c

Lagged Maximum Covariance Analysis (LMCA) is used to examine the intraseasonal variability of zonal wind, sea surface temperature (SST) and outgoing longwave radiation (OLR) in the Eastern Tropical Paci c Ocean during Northern Hemisphere summertime. Results show the eastward propagation of the Madden Julian Oscillation (MJO) signal at both 850 mb and 200 mb. The 850 mb zonal wind shows a jet-like structure that is associated with enhanced convection near the west coast of Central America and is followed by a period of suppressed convection in the ITCZ. Fractions of covariance explained by the rst singular vector are larger for time lags between 3 and 6 days. LMCA analysis con rms a synergistic relationship between large-scale wind and convection anomalies in that convection anomalies appear to both respond to wind anomalies and act to enhance them. The analysis shows a strong temporal asymmetry in that wind anomalies lead to SST anomalies, but SST anomalies are not followed by strong wind anomalies.