Land‐Locked Convection as a Barrier to MJO Propagation Across the Maritime Continent

Abstract

The Maritime Continent (MC) is a unique region of thousands of islands in the tropical Pacific warm pool with a very dynamic distribution of topography and terrain, and one of the main drivers of the global general circulation (Ramage, 1968). It lies at the intersection of many scales of atmospheric and oceanic variability, from decadal (El Niño-Southern Oscillation), to seasonal (monsoons), intraseasonal (the Madden-Julian Oscillation (MJO), Madden & Julian, 1971, 1972, and some of the strongest diurnal cycles in the world (Moron et al., 2015). Kikuchi and Wang (2008) classify the diurnal cycle (DC) over the MC into the coastal regime under which systems of land-and sea-breezes drive precipitation location and intensity, modified by the background circulation, orography, and coastline orientation (Abbs & Physick, 1992). Differential solar heating during the day induces a sea breeze circulation around islands and precipitation begins to form on the coast, then propagate inland from noon to evening; precipitation over the neighboring oceans is suppressed (Miller et al., 2003

Cloud and Precipitation Variability Associated With the Madden‐Julian Oscillation Over the Maritime Continent

“…However, the PR, GSMaP, and IMERG products also have almost zero precipitation anomalies in Phase 5. Thus, New Guinea is characterized by a rapid decrease in precipitation as the MJO envelope approaches, which is a characteristic of precipitation over MC land areas reported in previous studies (e.g., Chen et al., 2022; Ling et al., 2019; Savarin & Chen, 2023; Zhang & Ling, 2017), but Borneo with large positive anomalies in Phase 4 differs significantly.…”