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Spontaneous onset of a Madden‐Julian oscillation event in a cloud‐system‐resolving simulation
Author(s) -
Miura Hiroaki,
Satoh Masaki,
Katsumata Masaki
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl039056
Subject(s) - madden–julian oscillation , event (particle physics) , climatology , meteorology , cloud computing , oscillation (cell signaling) , geology , environmental science , physics , computer science , convection , biology , genetics , operating system , quantum mechanics
Spontaneous onset of a Madden‐Julian Oscillation (MJO) event in November 2006 was reproduced at a proper location and time by a global cloud‐resolving model (CRM) used with a relatively coarse horizontal grid. Preconditioning of moisture was simulated about 4‐days prior to the onset in the Indian Ocean, which agreed with data obtained in an in‐situ observation. To investigate influence of zonal Sea Surface Temperature (SST) gradient in the Indian Ocean, we conducted a sensitivity study comparing composites made from five ensemble simulations. It was found that the eastward‐moving signal of this MJO event could be obscured if SST were zonally uniform in the western Indian Ocean. Zonal SST gradient has not been considered important in the previous studies about the MJO onset, but SST distribution locating cooler SST in the west side possibly help enhance convection in slow eastward‐moving envelopes of the MJO.