气候变化领域集成服务门户(CCPortal): Exploring the factors influencing the strength and variability of convectively coupled Mixed Rossby-Gravity waves

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DOI	10.1175/JCLI-D-20-0218.1
	Exploring the factors influencing the strength and variability of convectively coupled Mixed Rossby-Gravity waves
	Suhas E.; Neena J.M.; Jiang X.
发表日期	2020
ISSN	0894-8755
起始页码	9705
结束页码	9719
卷号	33 期号:22
英文摘要	The three-dimensional structure, horizontal and vertical propagation characteristics, and convection-circulation coupling of the convectively coupled westward-propagating mixed Rossby-gravity (MRG) waves are examined by classifying the waves based on their amplitude. Convective signals of the MRG waves were identified and isolated using empirical orthogonal function analysis of wavenumber-frequency-filtered outgoing longwave radiation (OLR) data. It was found that about 50% of the MRG waves occur during the August-November months, and this strong seasonality was considered while characterizing the MRG waves. Five strong and five weak MRG wave seasons were identified during 1979-2019, based on seasonal wave amplitude, and through this classification, significant differences in the strength of convection-circulation coupling, zonal scale of circulation, vertical structure, and propagation characteristics of MRG waves were brought out. It was also found that the seasonal mean background state is significantly different during strong and weak MRG wave seasons. While a La Niña-like background state was found to favor enhanced MRG wave activity, the MRG wave activity is mostly suppressed during an El Niño-like background state. The presence of extratropical wave intrusions is another factor that distinguishes the strong MRG wave seasons from the weak ones. Eastward- and northeastwardpropagating extratropical wave trains from the South Atlantic to the east Indian Ocean were observed during strong MRG wave seasons. © 2020 American Meteorological Society.
英文关键词	Climate models; Climatology; East indian oceans; Empirical orthogonal function analysis; Outgoing longwave radiation; Propagation characteristics; Rossby-gravity wave; Three-dimensional structure; Vertical structures; Wave amplitudes; Orthogonal functions; amplitude; annual variation; atmospheric convection; convective system; gravity wave; longwave radiation; Rossby wave; tropical environment; wave propagation; Atlantic Ocean; Atlantic Ocean (South); Indian Ocean
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171014
作者单位	Earth and Climate Science, Indian Institute of Science Education and Research, Pune, Pune, India; Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, Los Angeles, CA, United States
推荐引用方式 GB/T 7714	Suhas E.,Neena J.M.,Jiang X.. Exploring the factors influencing the strength and variability of convectively coupled Mixed Rossby-Gravity waves[J],2020,33(22).
APA	Suhas E.,Neena J.M.,&Jiang X..(2020).Exploring the factors influencing the strength and variability of convectively coupled Mixed Rossby-Gravity waves.Journal of Climate,33(22).
MLA	Suhas E.,et al."Exploring the factors influencing the strength and variability of convectively coupled Mixed Rossby-Gravity waves".Journal of Climate 33.22(2020).