气候变化领域集成服务门户(CCPortal): Impact of SST diurnal cycle on ENSO asymmetry

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DOI	10.1007/s00382-018-4271-7
	Impact of SST diurnal cycle on ENSO asymmetry
	Tian F.; Storch J.-S.; Hertwig E.
发表日期	2019
ISSN	0930-7575
起始页码	2399
结束页码	2411
卷号	52 期号:2020-03-04
英文摘要	The dominant mode of inter-annual variability in the tropical Pacific is El Niño-Southern Oscillation (ENSO). ENSO is not symmetric in the sense that El Niño is generally stronger than La Niña. However, many CMIP5 models, including the Max Planck Institute Earth System Model (MPI-ESM), produce an almost symmetric ENSO. This paper shows that, when resolving the intra-daily air-sea interactions by coupling the atmospheric and oceanic model components once per hour, the simulated ENSO asymmetry is improved. The improvement is closely related to the simulated diurnal cycle of sea surface tempreature (SST). In the central tropical Pacific, the simulated diurnal range of SST is about 0.2 °C, up to 10% of SST anomalies of the simulated ENSO events. During El Niño events, the diurnal cycle of SST anomalies enhances the atmospheric moist instability, whereby triggering more convection in the central tropical Pacific. During La Niña and normal years, however, the mean convection is not changed by the included diurnal cycle of SST anomalies. As a result, the anomalies of the trades, which are directly related to the convection, are stronger during El Niño years than that during La Niña years, making El Niño to be stronger than La Niña via Bjerknes feedback. These results obtained with a low resolution MPI-ESM are further confirmed by simulation with the same model at higher spatial resolutions, suggesting that the role of the intra-daily air-sea interactions for the ENSO asymmetry is independent of model resolutions. © 2018, The Author(s).
语种	英语
scopus关键词	air-sea interaction; annual variation; atmosphere-ocean coupling; diurnal variation; El Nino-Southern Oscillation; La Nina; sea surface temperature; temperature anomaly; Pacific Ocean; Pacific Ocean (Tropical)
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146519
作者单位	Max Planck Institute for Meteorology, Hamburg, Germany; National Centre for Atmospheric Science, Department of Meteorology, University of Reading, Reading, United Kingdom
推荐引用方式 GB/T 7714	Tian F.,Storch J.-S.,Hertwig E.. Impact of SST diurnal cycle on ENSO asymmetry[J],2019,52(2020-03-04).
APA	Tian F.,Storch J.-S.,&Hertwig E..(2019).Impact of SST diurnal cycle on ENSO asymmetry.Climate Dynamics,52(2020-03-04).
MLA	Tian F.,et al."Impact of SST diurnal cycle on ENSO asymmetry".Climate Dynamics 52.2020-03-04(2019).