气候变化领域集成服务门户(CCPortal): The Impact of Slantwise Descending Dry Intrusions on the Marine Boundary Layer and Air-Sea Interface Over the ARM Eastern North Atlantic Site

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DOI	10.1029/2020JD033879
	The Impact of Slantwise Descending Dry Intrusions on the Marine Boundary Layer and Air-Sea Interface Over the ARM Eastern North Atlantic Site
	Ilotoviz E.; Ghate V.P.; Raveh-Rubin S.
发表日期	2021
ISSN	2169897X
卷号	126 期号:4
英文摘要	Dry intrusions (DIs) are synoptic-scale slantwise descending airstreams from the midlatitude upper troposphere toward the boundary layer at lower latitudes. Typically occurring behind cold fronts, such intrusions of dry air often reach the boundary layer and cause its deepening, thereby affecting boundary-layer clouds. Although subsidence is generally an inherent feature of the subtropical marine boundary layer (MBL), it is unclear how the MBL reacts to the transient, dynamically distinct DI. In this study, reanalysis data were combined with observations from the Atmospheric Radiation Measurement Eastern North Atlantic (ENA) site (39.1°N,28.0°W) to characterize the impact of DIs on MBL characteristics and clouds. Specifically, an objective criterion is applied to the observations made during the winter months of 2016–2018 to identify the DI days from those before and following DIs, and reference periods without DIs. The analyses suggest substantial deepening of the well-mixed boundary layer accompanied by changes in the cloud, precipitation and thermodynamic properties during the DI events. During the DI, the lower troposphere cooled and dried substantially thereby inducing strong surface sensible and latent heat fluxes. All while a strong inversion builds up at the elevated MBL top affecting cloud occurrence. The results show DIs to affect the boundary layer and cloud structure at the ENA site ∼21% of the time in winter months, with the response of the cloud fields to the DI-fronts substantially different than that to the non-DI fronts. Hence, the DI events should be considered while studying boundary layer and cloud processes in the region. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	boundary layer; clouds; cyclones; dry intrusions; inversion; surface fluxes
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185498
作者单位	Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel; Argonne National Laboratory, Lemont, IL, United States
推荐引用方式 GB/T 7714	Ilotoviz E.,Ghate V.P.,Raveh-Rubin S.. The Impact of Slantwise Descending Dry Intrusions on the Marine Boundary Layer and Air-Sea Interface Over the ARM Eastern North Atlantic Site[J],2021,126(4).
APA	Ilotoviz E.,Ghate V.P.,&Raveh-Rubin S..(2021).The Impact of Slantwise Descending Dry Intrusions on the Marine Boundary Layer and Air-Sea Interface Over the ARM Eastern North Atlantic Site.Journal of Geophysical Research: Atmospheres,126(4).
MLA	Ilotoviz E.,et al."The Impact of Slantwise Descending Dry Intrusions on the Marine Boundary Layer and Air-Sea Interface Over the ARM Eastern North Atlantic Site".Journal of Geophysical Research: Atmospheres 126.4(2021).