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dc.contributor.authorRay, Pallav
dc.contributor.authorLi, Tim
dc.date.accessioned2014-01-08T19:51:37Z
dc.date.available2014-01-08T19:51:37Z
dc.date.issued2013-03
dc.identifier.citationRay, P., & Li, T. (2013). Relative roles of circumnavigating waves and extratropics on the MJO and its relationship with the mean state. Journal of the Atmospheric Sciences, 70(3), 876-893.en_US
dc.identifier.urihttp://hdl.handle.net/11141/233
dc.description.abstractA set of atmospheric general circulation model (GCM) experiments is designed to explore the relative roles of the circumnavigating waves and the extratropics on the Madden-Julian oscillation (MJO). In a "control" simulation, the model is forced by the climatological monthly sea surface temperature for 20 yr. In the first sensitivity experiment, model prognostic variables are relaxed in the tropical Atlantic region (20°S-20°N, 80°W-0°) toward the "controlled" climatological annual cycle to suppress the influences from the circumnavigating waves. In the second sensitivity experiment, model prognostic variables are relaxed in the 20°-30° latitude zones toward the controlled climatological annual cycle to suppress the influences from the extratropics (or the tropics-extratropics interactions). The numerical results demonstrate that the extratropics play a more important role in maintaining the MJO variance than the circumnavigating waves. The simulations further show that both the tropical mean precipitation and the intraseasonal precipitation variability are reduced when the extratropical influences are suppressed. The in-phase relationship is primarily attributed to the effect of the mean state on perturbations. A moisture budget analysis indicates that a positive feedback to themean precipitation by the anomalousmoisture convergence is offset by a negative feedback due to the anomalous moisture advection. The change in the mean precipitation in the absence of extratropical influences is primarily determined by the change in the mean moisture convergence, which in turn is due to the change in circulation. This study is the first attempt to quantitatively separate the effects of the circumnavigating waves and the extratropics on the MJO. Implications and limitations of this study are discussed.en_US
dc.language.isoen_USen_US
dc.rightsThis published article is available in accordance with the publisher's policy. It may be subject to U.S. copyright law.en_US
dc.rights.urihttp://www2.ametsoc.org/ams/index.cfm/publications/authors/journal-and-bams-authors/author-resources/copyright-information/copyright-policy/en_US
dc.titleRelative roles of circumnavigating waves and extratropics on the MJO and its relationship with the mean stateen_US
dc.typeArticleen_US
dc.identifier.doi10.1175/JAS-D-12-0153.1


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