气候变化领域集成服务门户(CCPortal): Effects of high-frequency activity on latent heat flux of MJO

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DOI	10.1007/s00382-018-4208-1
	Effects of high-frequency activity on latent heat flux of MJO
	Gao Y.; Hsu P.-C.; Li T.
发表日期	2019
ISSN	0930-7575
起始页码	1471
结束页码	1485
卷号	52 期号:2020-03-04
英文摘要	The effect of high-frequency (HF) variability on latent heat flux (LHF) associated with the Madden–Julian Oscillation (MJO) during the boreal winter is investigated through diagnosis using two reanalysis datasets and numerical experiments of an atmospheric general circulation model (AGCM). The diagnostic results show that the HF activities exert an impact on the variability of MJO LHF mainly through their interactions with the longer than 90-day low-frequency background state (LFBS). The contribution of intraseasonal LHF induced by the interactions between LFBS and HF activities accounts for more than 20% of the total intraseasonal LHF over active MJO regions. The intraseasonal LHF induced by the LFBS–HF interaction is in phase with the MJO convection, while the total intraseasonal LHF appears at and to the west of the MJO convection center. This suggests that the intraseasonal LHF via the feedback of HF activity interacting with LFBS is conducive to the maintenance and eastward propagation of MJO convection. To confirm the role of HF disturbances in MJO convection activity, we carry out a series of experiments using the AGCM of ECHAM4, which captures well the general features of MJO. We select a number of MJO cases with enhanced convective signals and significant eastward propagation from a 30-year climatological simulation. Once the HF components of surface wind and moisture fields in LHF are excluded in model integration for each MJO case, most of the simulated MJO convection shows weakened activity and a slower propagation speed compared to the simulations containing all time-scale components. The outputs of these sensitivity experiments support the diagnostic results that HF activities contribute to the maintenance and propagation of MJO convection through the intraseasonal LHF induced by the scale interaction of HF activities with lower frequency variability. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	High-frequency activity; Latent heat flux; Madden–Julian Oscillation; Scale interaction
语种	英语
scopus关键词	atmospheric general circulation model; atmospheric moisture; latent heat flux; Madden-Julian oscillation; surface wind; winter
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/146567
作者单位	International Laboratory on Climate and Environment Change and Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China; International Pacific Research Center, University of Hawaii, Manoa, HI, United States
推荐引用方式 GB/T 7714	Gao Y.,Hsu P.-C.,Li T.. Effects of high-frequency activity on latent heat flux of MJO[J],2019,52(2020-03-04).
APA	Gao Y.,Hsu P.-C.,&Li T..(2019).Effects of high-frequency activity on latent heat flux of MJO.Climate Dynamics,52(2020-03-04).
MLA	Gao Y.,et al."Effects of high-frequency activity on latent heat flux of MJO".Climate Dynamics 52.2020-03-04(2019).