气候变化领域集成服务门户(CCPortal): Analysis of Coupled Oceanic and Atmospheric Preconditioning for Primary Madden-Julian Oscillation Events Across ENSO Phases

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DOI	10.1029/2020JC016358
	Analysis of Coupled Oceanic and Atmospheric Preconditioning for Primary Madden-Julian Oscillation Events Across ENSO Phases
	Shoup C.G.; Roman-Stork H.L.; Subrahmanyam B.
发表日期	2020
ISSN	21699275
卷号	125 期号:9
英文摘要	The Madden-Julian Oscillation (MJO) is the dominant mode of air-sea interaction over intraseasonal timescales. The effects of the MJO are well understood, but the initiation of the MJO remains less conclusive, particularly under El Niño Southern Oscillation (ENSO) conditions. Primary MJO events are those not immediately preceded by existing MJO activity of sufficient strength. As they are rare by definition, primary MJOs remain difficult to study, especially so when observations of events are scarce and of low spatiotemporal resolution. The advent of satellites allows for more expansive observations to be made more frequently than in situ methods, thus improving the observational capabilities of pre-primary MJO conditions in the ocean and atmosphere. We examined oceanic and atmospheric intraseasonal signals preceding two primary MJO events during contrasting ENSO events in an attempt to bridge the connection between oceanic and atmospheric observations as potentially coupled trigger mechanisms. Satellite observations and model simulations of the central and western Indian Ocean show that intraseasonal peaks in absolute dynamic topography (ADT) and sea surface temperature (SST) upward of 1 to 2 weeks prior to the observed outgoing longwave radiation (OLR) minimum. Surface ocean warming moistens the near surface through anomalous surface fluxes, which destabilizes the lower atmosphere to deep convection. Low-level moisture flux convergence (MFC) moistens the lower atmosphere prior to convective initiation, thus forcing an increase of total column moist static energy (MSE). Coupled midtropospheric cooling is observed that further destabilizes the atmosphere. Zonal shifts in contributing initiating parameters are observed during ENSO phases. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	ENSO; Indian Ocean; Indian Ocean Dipole; MJO; moist static energy; primary MJO
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186690
作者单位	School of the Earth, Ocean, and Environment, University of South Carolina, Columbia, SC, United States
推荐引用方式 GB/T 7714	Shoup C.G.,Roman-Stork H.L.,Subrahmanyam B.. Analysis of Coupled Oceanic and Atmospheric Preconditioning for Primary Madden-Julian Oscillation Events Across ENSO Phases[J],2020,125(9).
APA	Shoup C.G.,Roman-Stork H.L.,&Subrahmanyam B..(2020).Analysis of Coupled Oceanic and Atmospheric Preconditioning for Primary Madden-Julian Oscillation Events Across ENSO Phases.Journal of Geophysical Research: Oceans,125(9).
MLA	Shoup C.G.,et al."Analysis of Coupled Oceanic and Atmospheric Preconditioning for Primary Madden-Julian Oscillation Events Across ENSO Phases".Journal of Geophysical Research: Oceans 125.9(2020).