气候变化领域集成服务门户(CCPortal): How Does the Air-Sea Coupling Frequency Affect Convection During the MJO Passage?

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DOI	10.1029/2020MS002058
	How Does the Air-Sea Coupling Frequency Affect Convection During the MJO Passage?
	Zhao N.; Nasuno T.
发表日期	2020
ISSN	19422466
卷号	12 期号:4
英文摘要	The importance of air-sea coupling in the simulation and prediction of the Madden-Julian Oscillation (MJO) has been well established. However, it remains unclear how air-sea coupling modulates the convection and related oceanic features on the subdaily scale. Based on a regional cloud-permitting coupled model, we evaluated the impact of the air-sea coupling on the convection during the convectively active phase of the MJO by varying the coupling frequency. The model successfully reproduced the atmospheric and oceanic variations observed by satellite and in situ measurements but with some quantitative biases. According to the sensitivity experiments, we found that stronger convection was mainly caused by the higher sea surface temperatures (SSTs) generated in high-frequency coupled experiments, especially when the coupling frequency was 1 hr or shorter. A lower coupling frequency would generate the phase lags in the diurnal cycle of SST and related turbulent heat fluxes. Our analyses further demonstrated that the phase-lagged diurnal cycle of SST suppressed deep convection through a decrease in daytime moistening in the lower troposphere. Meanwhile, in the upper ocean, the high-frequency air-sea coupling helped maintain the shallower mixed and isothermal layers by diurnal heating and cooling at the sea surface, which led to a higher mean SST. In contrast, the low-frequency coupled experiments underestimated the SST and therefore convective activities. Overall, our results demonstrated that high-frequency air-sea coupling (1 hr or shorter) could improve the reproducibility of the intensity and temporal variation in both diurnal convection and upper ocean processes. ©2020. The Authors.
英文关键词	air-sea coupling; convection; coupling frequency; Madden-Julian Oscillation; upper ocean
语种	英语
scopus关键词	Climatology; Surface waters; Convective activity; Coupling frequencies; Heating and cooling; In-situ measurement; Madden-Julian oscillation; Sea surface temperatures; Turbulent heat fluxes; Upper ocean process; Oceanography; atmosphere-ocean coupling; atmospheric convection; cooling; diurnal variation; frequency analysis; heating; in situ measurement; Madden-Julian oscillation; satellite data; sea surface temperature
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156727
作者单位	Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
推荐引用方式 GB/T 7714	Zhao N.,Nasuno T.. How Does the Air-Sea Coupling Frequency Affect Convection During the MJO Passage?[J],2020,12(4).
APA	Zhao N.,&Nasuno T..(2020).How Does the Air-Sea Coupling Frequency Affect Convection During the MJO Passage?.Journal of Advances in Modeling Earth Systems,12(4).
MLA	Zhao N.,et al."How Does the Air-Sea Coupling Frequency Affect Convection During the MJO Passage?".Journal of Advances in Modeling Earth Systems 12.4(2020).