气候变化领域集成服务门户(CCPortal): The interplay of thermodynamics and ocean dynamics during ENSO growth phase

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DOI	10.1007/s00382-020-05552-4
	The interplay of thermodynamics and ocean dynamics during ENSO growth phase
	Bayr T.; Drews A.; Latif M.; Lübbecke J.
发表日期	2021
ISSN	0930-7575
卷号	56 期号:2021-05-06
英文摘要	The growth of El Niño/Southern Oscillation (ENSO) events is determined by the balance between ocean dynamics and thermodynamics. Here we quantify the contribution of the thermodynamic feedbacks to the sea surface temperature (SST) change during ENSO growth phase by integrating the atmospheric heat fluxes over the temporarily and spatially varying mixed layer to derive an offline “slab ocean” SST. The SST change due to ocean dynamics is estimated as the residual with respect to the total SST change. In observations, 1 K SST change in the Niño3.4 region is composed of an ocean dynamical SST forcing of + 2.6 K and a thermodynamic damping of − 1.6 K, the latter mainly by the shortwave-SST (− 0.9 K) and latent heat flux-SST feedback (− 0.7 K). Most climate models from the Coupled Model Intercomparison Project phase 5 (CMIP5) underestimate the SST change due to both ocean dynamics and net surface heat fluxes, revealing an error compensation between a too weak forcing by ocean dynamics and a too weak damping by atmospheric heat fluxes. In half of the CMIP5 models investigated in this study, the shortwave-SST feedback erroneously acts as an amplifying feedback over the eastern equatorial Pacific, resulting in a hybrid of ocean-driven and shortwave-driven ENSO dynamics. Further, the phase locking and asymmetry of ENSO is investigated in the CMIP5 model ensemble. The climate models with stronger atmospheric feedbacks tend to simulate a more realistic seasonality and asymmetry of the heat flux feedbacks, and they exhibit more realistic phase locking and asymmetry of ENSO. Moreover, the almost linear latent heat flux feedback contributes to ENSO asymmetry in the far eastern equatorial Pacific through an asymmetry in the mixed layer depth. This study suggests that the dynamic and thermodynamic ENSO feedbacks and their seasonality and asymmetries are important metrics to consider for improving ENSO representation in climate models. © 2020, The Author(s).
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/183384
作者单位	GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, Kiel, 24105, Germany; Department of Environment and New Resources, SINTEF Ocean AS, Trondheim, Norway; Faculty of Mathematics and Natural Sciences, Christian-Albrechts-University of Kiel, Kiel, 24105, Germany
推荐引用方式 GB/T 7714	Bayr T.,Drews A.,Latif M.,et al. The interplay of thermodynamics and ocean dynamics during ENSO growth phase[J],2021,56(2021-05-06).
APA	Bayr T.,Drews A.,Latif M.,&Lübbecke J..(2021).The interplay of thermodynamics and ocean dynamics during ENSO growth phase.Climate Dynamics,56(2021-05-06).
MLA	Bayr T.,et al."The interplay of thermodynamics and ocean dynamics during ENSO growth phase".Climate Dynamics 56.2021-05-06(2021).