气候变化领域集成服务门户(CCPortal): The Influence of Convective Momentum Transport and Vertical Wind Shear on the Evolution of a Cold Air Outbreak

CCPortal

DOI	10.1029/2019MS001991
	The Influence of Convective Momentum Transport and Vertical Wind Shear on the Evolution of a Cold Air Outbreak
	Saggiorato B.; Nuijens L.; Siebesma A.P.; de Roode S.; Sandu I.; Papritz L.
发表日期	2020
ISSN	19422466
卷号	12 期号:6
英文摘要	To study the influence of convective momentum transport (CMT) on wind, boundary layer and cloud evolution in a marine cold air outbreak (CAO) we use large-eddy simulations subject to different baroclinicity (wind shear) but similar surface forcing. The simulated domain is large enough, (Formula presented.) km2), to develop typical mesoscale cellular convective structures. We find that a maximum friction induced by momentum transport (MT) locates in the cloud layer for an increase of geostrophic wind with height (forward shear, FW) and near the surface for a decrease of wind with height (backward shear, BW). Although the total MT always acts as a friction, the interaction of friction-induced cross-isobaric flow with the Coriolis force can develop supergeostrophic winds near the surface (FW) or in the cloud layer (BW). The contribution of convection to MT is evaluated by decomposing the momentum flux by column water vapor and eddy size, revealing that CMT acts to accelerate subcloud layer winds under FW shear and that mesoscale circulations contribute significantly to MT for this horizontal resolution (250 m), even if small-scale eddies are nonnegligible and likely more important as resolution increases. Under FW shear, a deeper boundary layer and faster cloud transition are simulated, because MT acts to increase surface fluxes and wind shear enhances turbulent mixing across cloud tops. Our results show that the coupling between winds and convection is crucial for a range of problems, from CAO lifetime and cloud transitions to ocean heat loss and near-surface wind variability. ©2020. The Authors.
英文关键词	cold air outbreak; convective momentum transport; horizontal wind; kinetic energy budget; momentum transport; wind shear
语种	英语
scopus关键词	Boundary layers; Friction; Large eddy simulation; Momentum; Momentum transfer; Wind; Cold air outbreak; Horizontal resolution; Mesoscale circulation; Momentum transports; Near-surface winds; Resolution increase; Simulated domains; Vertical wind shear; Meteorology; boundary layer; cold air; convection; Coriolis force; large eddy simulation; mesoscale eddy; momentum; turbulent mixing; wind shear
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/156707
作者单位	Geoscience and Remote Sensing, Delft University of Technology, Delft, Netherlands; Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands; European Centre for Medium-Range Weather Forecasts (ECMWF), Reading, United Kingdom; Institute for Atmospheric and Climate Science, ETH, Zürich, Switzerland
推荐引用方式 GB/T 7714	Saggiorato B.,Nuijens L.,Siebesma A.P.,et al. The Influence of Convective Momentum Transport and Vertical Wind Shear on the Evolution of a Cold Air Outbreak[J],2020,12(6).
APA	Saggiorato B.,Nuijens L.,Siebesma A.P.,de Roode S.,Sandu I.,&Papritz L..(2020).The Influence of Convective Momentum Transport and Vertical Wind Shear on the Evolution of a Cold Air Outbreak.Journal of Advances in Modeling Earth Systems,12(6).
MLA	Saggiorato B.,et al."The Influence of Convective Momentum Transport and Vertical Wind Shear on the Evolution of a Cold Air Outbreak".Journal of Advances in Modeling Earth Systems 12.6(2020).