Rectified Wind Forcing and Latent Heat Flux Produced by the Madden–Julian Oscillation

Abstract

Rectification of (Madden?Julian oscillation) MJO-induced wind speed and latent heat flux variations across the tropical Indian and western Pacific Oceans is estimated using 51 yr of NCEP?NCAR reanalysis. The rectified wind speed anomaly is calculated from the difference in wind speed based on 30- and 90-day low-pass-filtered winds. During periods when the MJO is active, the wind speed is typically enhanced by about 1 m s?1 south of the equator in the western Pacific. The largest rectified latent heat flux occurred during the large MJO event of March 1997 in the western Pacific warm pool. The magnitude of the rectification is found to depend strongly on the mean wind speed, and this affects the temporal and spatial variations of the rectification.