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DOI	10.1175/JCLI-D-19-0377.1
	Local rossby wave packet amplitude, phase speed, and group velocity: Seasonal variability and their role in temperature extremes
	Fragkoulidis G.; Wirth V.
发表日期	2020
ISSN	08948755
起始页码	8767
结束页码	8787
卷号	33 期号:20
英文摘要	Transient Rossby wave packets (RWPs) are a prominent feature of the synoptic to planetary upper-tropospheric flow at the midlatitudes. Their demonstrated role in various aspects of weather and climate prompts the investigation of characteristic properties like their amplitude, phase speed, and group velocity. Traditional frameworks for the diagnosis of the two latter have so far remained nonlocal in space or time, thus preventing a detailed view on the spatiotemporal evolution of RWPs. The present work proposes a method for the diagnosis of horizontal Rossby wave phase speed and group velocity locally in space and time. The approach is based on the analytic signal of upper-tropospheric meridional wind velocity and RWP amplitude, respectively. The new diagnostics are first applied to illustrative examples from a barotropic model simulation and the real atmosphere. The main seasonal and interregional variability features of RWP amplitude, phase speed, and group velocity are then explored using ERA5 reanalysis data for the time period 1979-2018. Apparent differences and similarities in these respects between the Northern and Southern Hemispheres are also discussed. Finally, the role of RWP amplitude and phase speed during central European short-lived and persistent temperature extremes is investigated based on changes of their distribution compared to the climatology of the region. The proposed diagnostics offer insight into the spatiotemporal variability of RWP properties and allow the evaluation of their implications at low computational demands. Ó 2020 American Meteorological Society.
英文关键词	Atmospheric circulation; Climatology; Extreme events; Fourier analysis; Rossby waves; Wave properties
语种	英语
scopus关键词	Light velocity; Meteorology; Troposphere; Wave packets; American meteorological societies; Barotropic model simulations; Characteristic properties; Computational demands; Seasonal variability; Spatiotemporal evolution; Spatiotemporal variability; Temperature extremes; Mechanical waves; barotropic motion; extreme event; meridional circulation; numerical model; Rossby wave; seasonal variation; temperature profile; troposphere; wind velocity
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/178720
作者单位	Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, Germany
推荐引用方式 GB/T 7714	Fragkoulidis G.,Wirth V.. Local rossby wave packet amplitude, phase speed, and group velocity: Seasonal variability and their role in temperature extremes[J],2020,33(20).
APA	Fragkoulidis G.,&Wirth V..(2020).Local rossby wave packet amplitude, phase speed, and group velocity: Seasonal variability and their role in temperature extremes.Journal of Climate,33(20).
MLA	Fragkoulidis G.,et al."Local rossby wave packet amplitude, phase speed, and group velocity: Seasonal variability and their role in temperature extremes".Journal of Climate 33.20(2020).