A 20-Year Climatology of Madden-Julian Oscillation Convection: Large-Scale Precipitation Tracking From TRMM-GPM Rainfall

摘要

This study presents a 20-year climatology of the Madden-Julian Oscillation (MJO) convection based on Large-scale Precipitation Tracking (LPT) using TRMM-GPM Multisatellite Precipitation Analysis (TMPA) data from 1998-2018 over the global tropics-midlatitudes (50°S-50°N). A total of 215 convective events are identified as MJO LPT systems over the 20 years, extending the results of Kerns and Chen (2016, https://doi.org/10.1002/2015JD024661). MJO LPT systems provide quantitative information regarding size, intensity, and location of the MJO convection in both the longitudinal and meridional directions. The MJO contributes up to 40-50% of the annual precipitation over the tropical Indo-Pacific warm pool. MJO LPT systems have distinct seasonal and interannual variability. While MJO LPT systems are generally confined over the equatorial tropics during Boreal winter, some MJO LPT systems propagate northeast in the Bay of Bengal or from the South China Sea to the western North Pacific during Boreal summer. MJO LPT systems are more than doubled over the Indian Ocean (IO) and Maritime Continent (MC) during La Nina compared to El Nino. The 63% of MJO LPT systems initiate over the tropical IO, 26% over the MC and western Pacific, and 11% from the central Pacific to South America. About 40% of the MJO LPT systems that initialized over the IO were unable to propagate through the MC, namely, the barrier effect. The MC barrier effect is most pronounced during the spring and autumn transitions. This 20-year MJO LPT climatology product will be provided as a supplement to this publication.