气候变化领域集成服务门户(CCPortal): Improving MJO simulation by enhancing the interaction between boundary layer convergence and lower tropospheric heating

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DOI	10.1007/s00382-018-4407-9
	Improving MJO simulation by enhancing the interaction between boundary layer convergence and lower tropospheric heating
	Yang Y.-M.; Wang B.
发表日期	2019
ISSN	0930-7575
起始页码	4671
结束页码	4693
卷号	52 期号:2020-07-08
英文摘要	It has been a great challenge for global weather and climate models to simulate realistic Madden–Julian Oscillation (MJO) while keeping global energy and water balance unaffected. This work demonstrates that, in the Nanjing University of Information Science and Technology Earth System Model, enhanced boundary layer (BL) convergence feedback to the lower tropospheric heating in both the modified Tidtke (TDK) and relaxed Arakawa–Schubert (RAS) convective schemes have significantly improved the quality of MJO simulation in terms of both the eastward propagation and three-dimensional dynamic and thermodynamic structures. The modifications to the TDK and RAS schemes include (a) a BL depth-dependent convective inhibition, and (b) a bottom-heavy diffusivity in the shallow convection scheme. To understand how these modifications improved the MJO simulation, we applied dynamics-oriented diagnostics to reveal the critical role of the interaction between the lower-tropospheric heating and the BL convergence. The modified schemes enhance the lower-tropospheric diabatic heating to the east of the MJO convective center, which leads to increased Kelvin wave easterly winds. The strengthened MJO easterly winds reinforce the BL moisture convergence to the east of the MJO center and therefore result in increased upward transports of moisture and heat from the BL to the free atmosphere, which further moisten and destabilize the lower troposphere and thereby increase the lower-tropospheric heating. The positive feedback between the BL convergence and lower tropospheric heating improves MJO eddy available potential energy generation to the east of major convection and promotes MJO eastward propagation. The results indicate that correct simulation of the heating induced by shallow and/or congestus clouds and its interaction with BL dynamics is critical for realistic simulation of the MJO as suggested by the trio-interaction theory. © 2018, The Author(s).
英文关键词	Boundary layer convergence feedback; MJO; MJO dynamics; MJO simulation; Shallow and congestus clouds
语种	英语
scopus关键词	atmospheric moisture; boundary layer; climate modeling; cloud cover; convection; convergence; heating; Madden-Julian oscillation; troposphere
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/146387
作者单位	Earth System Modeling Center, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China; Department of Atmospheric Sciences and International Pacific Research Center, University of Hawaii, Honolulu, HI 96822, United States
推荐引用方式 GB/T 7714	Yang Y.-M.,Wang B.. Improving MJO simulation by enhancing the interaction between boundary layer convergence and lower tropospheric heating[J],2019,52(2020-07-08).
APA	Yang Y.-M.,&Wang B..(2019).Improving MJO simulation by enhancing the interaction between boundary layer convergence and lower tropospheric heating.Climate Dynamics,52(2020-07-08).
MLA	Yang Y.-M.,et al."Improving MJO simulation by enhancing the interaction between boundary layer convergence and lower tropospheric heating".Climate Dynamics 52.2020-07-08(2019).