气候变化领域集成服务门户(CCPortal): New insights into Rossby wave packet properties in the extratropical UTLS using GNSS radio occultations

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DOI	10.5194/acp-20-11569-2020
	New insights into Rossby wave packet properties in the extratropical UTLS using GNSS radio occultations
	Kedzierski R.P.; Matthes K.; Bumke K.
发表日期	2020
ISSN	1680-7316
起始页码	11569
结束页码	11592
卷号	20 期号:19
英文摘要	The present study describes Rossby wave packet (RWP) properties in the upper troposphere and lower stratosphere (UTLS) with the use of Global Navigation Satellite System radio occultation (GNSS-RO) measurements. This global study covering both hemispheres’ extratropics is the first to tackle medium- and synoptic-scale waves with GNSS-RO. We use 1 decade of GNSS-RO temperature and pressure data from the CHAMP, COSMIC, GRACE, Metop-A, Metop-B, SAC-C and TerraSAR-X missions, combining them into one gridded dataset for the years 2007–2016. Our approach to extract RWP anomalies and their envelope uses Fourier and Hilbert transforms over longitude without pre- or post-processing the data. Our study is purely based on observations, only using ERA-Interim winds to provide information about the background wind regimes. The RWP structures that we obtain in the UTLS agree well with theory and earlier studies, in terms of coherent phase or group propagation, zonal scale and distribution over latitudes. Furthermore, we show that RWP pressure anomalies maximize around the tropopause, while RWP temperature anomalies maximize right above the tropopause height with a contrasting minimum right below. RWP activity follows the zonal-mean tropopause during all seasons. RWP anomalies in the lower stratosphere are dynamically coupled to the upper troposphere. They are part of the same system with a quasi-barotropic structure across the UTLS. RWP activity often reaches up to 20 km height and occasionally higher, defying the Charney–Drazin criterion. We note enhanced amplitude and upward propagation of RWP activity during sudden stratospheric warmings. We provide observational support for improvements in RWP diagnostics and wave trend analysis in models and reanalyses. Wave quantities follow the tropopause, and diagnosing them on fixed pressure levels (which the tropopause does not follow) can lead to aliasing. Our novel approach analyzing GNSS-RO pressure anomalies provides wave signals with better continuity and coherence across the UTLS and the stratosphere, compared to temperature anomalies. Thus, RWP vertical propagation is much easier to analyze with pressure data. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/141077
作者单位	Marine Meteorology Department, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; Faculty of Mathematics and Natural Sciences, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
推荐引用方式 GB/T 7714	Kedzierski R.P.,Matthes K.,Bumke K.. New insights into Rossby wave packet properties in the extratropical UTLS using GNSS radio occultations[J],2020,20(19).
APA	Kedzierski R.P.,Matthes K.,&Bumke K..(2020).New insights into Rossby wave packet properties in the extratropical UTLS using GNSS radio occultations.Atmospheric Chemistry and Physics,20(19).
MLA	Kedzierski R.P.,et al."New insights into Rossby wave packet properties in the extratropical UTLS using GNSS radio occultations".Atmospheric Chemistry and Physics 20.19(2020).