Spontaneous onset of a Madden-Julian oscillation event in a cloud-system-resolving simulation
Article first published online: 2 JUL 2009
Copyright 2009 by the American Geophysical Union.
Geophysical Research Letters
Volume 36, Issue 13, July 2009
How to Cite
2009), Spontaneous onset of a Madden-Julian oscillation event in a cloud-system-resolving simulation, Geophys. Res. Lett., 36, L13802, doi:10.1029/2009GL039056., , and (
- Issue published online: 2 JUL 2009
- Article first published online: 2 JUL 2009
- Manuscript Accepted: 9 JUN 2009
- Manuscript Received: 5 MAY 2009
- MJO onset;
- global CRM;
- zonal SST gradient
 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.