气候变化领域集成服务门户(CCPortal): Barotropic Instability of a Cyclone Core at Kilometer-Scale Resolution

CCPortal

DOI	10.1029/2019MS001847
	Barotropic Instability of a Cyclone Core at Kilometer-Scale Resolution
	Leutwyler D.; Schär C.
发表日期	2019
ISSN	19422466
起始页码	3390
结束页码	3402
卷号	11 期号:11
英文摘要	Secondary disturbances spawning frontal waves along the fronts of mature midlatitude low-pressure systems were identified decades ago from satellite images and during field campaigns. Today's flagship supercomputers allow performing simulations at kilometer-scale resolution on computational domains covering the entire lifecycle of synoptic-scale systems and thus enable explicit representation of small-scale disturbances embedded in large-scale circulations. Here we demonstrate these capabilities in two different types of kilometer-scale simulations. The first is a 10-day-long near-global simulation of an idealized moist baroclinic wave, performed at 1 km grid spacing and employing 16,001 × 36,006 × 60 grid points. The second is a real-case simulation of an extratropical low-pressure system, driven by the European Centre for Medium-Range Weather Forecasts's operational analysis. At kilometer-scale resolution, both simulations display clear evidence of embedded mesoscale vortices spawning along frontal systems of mature extratropical cyclones. The vortices appearing in the real-case simulation can also be identified in satellite imagery of the system. The simulated developments are due to a barotropic instability mechanism and driven by strong low-level horizontal wind shear. While the simulation of the frontal systems is amenable at model resolutions around 10–50 km, the instability mechanism itself relies on the representation of a narrow shear zone, requiring about 5 times finer resolution. Results suggest that the flow regimes suppressing or fostering barotropic vortices can coexist in the same synoptic system. Far away from the cyclone core, the instability is suppressed by deformation associated with the large-scale flow, while close to the mature cyclone core, the narrow frontal structure becomes unstable. ©2019. The Authors.
英文关键词	barotropic instability; convection-resolving; extratropical cyclone; GPU; graphics processing unit; idealized baroclinic wave; mesovortex
语种	英语
scopus关键词	Computer graphics; Computer graphics equipment; Embedded systems; Graphics processing unit; Program processors; Satellite imagery; Storms; Supercomputers; Vortex flow; Weather forecasting; Baroclinic waves; Barotropic; European centre for medium-range weather forecasts; Explicit representation; Extratropical cyclones; Large-scale circulation; Mesovortex; Small-scale disturbances; Stability; baroclinic wave; barotropic instability; deformation; extratropical cyclone; satellite imagery; shear zone
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156835
作者单位	Atmospheric and Climate Science, ETH Zürich, Zürich, Switzerland
推荐引用方式 GB/T 7714	Leutwyler D.,Schär C.. Barotropic Instability of a Cyclone Core at Kilometer-Scale Resolution[J],2019,11(11).
APA	Leutwyler D.,&Schär C..(2019).Barotropic Instability of a Cyclone Core at Kilometer-Scale Resolution.Journal of Advances in Modeling Earth Systems,11(11).
MLA	Leutwyler D.,et al."Barotropic Instability of a Cyclone Core at Kilometer-Scale Resolution".Journal of Advances in Modeling Earth Systems 11.11(2019).