气候变化领域集成服务门户(CCPortal): Empirical evidence for deep convection being a major source of stratospheric ice clouds over North America

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DOI	10.5194/acp-21-10457-2021
	Empirical evidence for deep convection being a major source of stratospheric ice clouds over North America
	Zou L.; Hoffmann L.; Griessbach S.; Spang R.; Wang L.
发表日期	2021
ISSN	1680-7316
起始页码	10457
结束页码	10475
卷号	21 期号:13
英文摘要	Ice clouds in the lowermost stratosphere affect stratospheric water vapour and the Earth's radiation budget. The knowledge of its occurrence and driving forces is limited. To assess the distribution and possible formation mechanisms of stratospheric ice clouds (SICs) over North America, we analysed SIC occurrence frequencies observed by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) instrument during the years 2006 to 2018. Possible driving forces such as deep convection are assessed based on Atmospheric Infrared Sounder (AIRS) observations during the same time. Results show that at nighttime, SICs are most frequently observed during the thunderstorm season over the Great Plains from May to August (MJJA) with a maximum occurrence frequency of 6.2%. During the months from November to February (NDJF), the highest SICs occurrence frequencies are 5.5% over the north-eastern Pacific and western Canada and 4.4% over the western North Atlantic. Occurrence frequencies of deep convection from AIRS, which includes storm systems, fronts, mesoscale convective systems, and mesoscale convective complexes at midlatitude and high latitude, show similar hotspots like the SICs, with highest occurrence frequencies being observed over the Great Plains in MJJA (4.4%) and over the north-eastern Pacific, western Canada, and the western North Atlantic in NDJF (1/42.5%). Both, seasonal patterns and daily time series of SICs and deep convection show a high degree of spatial and temporal relation. Further analysis indicates that the maximum fraction of SICs related to deep convection is 74% over the Great Plains in MJJA and about 50% over the western North Atlantic, the north-eastern Pacific, and western Canada in NDJF. We conclude that, locally and regionally, deep convection is the leading factor related to the occurrence of SICs over North America. In this study, we also analysed the impact of gravity waves as another important factor related to the occurrence of SICs, as the Great Plains is a well-known hotspot for stratospheric gravity waves. In the cases where SICs are not directly linked to deep convection, we found that stratospheric gravity wave observations correlate with SICs with as much as 30% of the cases over the Great Plains in MJJA, about 50% over the north-eastern Pacific and western Canada, and up to 90% over eastern Canada and the north-west Atlantic in NDJF. Our results provide a better understanding of the physical processes and climate variability related to SICs and will be of interest for modellers as SIC sources such as deep convection and gravity waves are small-scale processes that are difficult to represent in global general circulation models. © 2021 The Author(s). Published by Cambridge University Press.
语种	英语
scopus关键词	atmospheric convection; CALIPSO; cloud microphysics; convective system; formation mechanism; general circulation model; ice; marine atmosphere; mesoscale meteorology; radiation budget; stratosphere; water vapor; Atlantic Ocean; Atlantic Ocean (North); Canada; Pacific Ocean; Pacific Ocean (Northeast)
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/246740
作者单位	Jülich Supercomputing Centre, Forschungszentrum Jülich, Jülich, Germany; Institute of Energy and Climate Research (IEK-7), Forschungszentrum Jülich, Jülich, Germany; Hubei Key Laboratory of Critical Zone Evolution, School of Geography and Information Engineering, China University of Geosciences, Wuhan, China
推荐引用方式 GB/T 7714	Zou L.,Hoffmann L.,Griessbach S.,et al. Empirical evidence for deep convection being a major source of stratospheric ice clouds over North America[J],2021,21(13).
APA	Zou L.,Hoffmann L.,Griessbach S.,Spang R.,&Wang L..(2021).Empirical evidence for deep convection being a major source of stratospheric ice clouds over North America.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(13).
MLA	Zou L.,et al."Empirical evidence for deep convection being a major source of stratospheric ice clouds over North America".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.13(2021).