The Amplification of East Pacific Madden–Julian Oscillation Convection and Wind Anomalies during June–November

Abstract

Abstract Madden–Julian oscillation (MJO) wind and convection anomalies are locally amplified over the northeast Pacific warm pool during June–November. Composite analysis using NCEP reanalysis data indicates that perturbation available potential energy (PAPE) production through the positive correlation of intraseasonal temperature and convective diabatic heating anomalies supports the local intensification of MJO-related east Pacific warm pool wind anomalies. PAPE production is maximum during periods of strong MJO convection and low-level westerly wind perturbations. PAPE is converted to perturbation kinetic energy through positive correlations between intraseasonal temperature and vertical velocity. Microwave Sounding Unit (MSU) temperature and NOAA outgoing longwave radiation data support the energy budget results derived from NCEP reanalysis. The amplified east Pacific circulation enhances surface convergence and latent heat flux anomalies during MJO convective periods. The surface convergence anomalie...