气候变化领域集成服务门户(CCPortal): A meteorological overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the southeastern Atlantic during 2016-2018: Part 1

CCPortal

DOI	10.5194/acp-21-16689-2021
	A meteorological overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the southeastern Atlantic during 2016-2018: Part 1 - Climatology
	Ryoo J.-M.; Pfister L.; Ueyama R.; Zuidema P.; Wood R.; Chang I.; Redemann J.
发表日期	2021
ISSN	1680-7316
起始页码	16689
结束页码	16707
卷号	21 期号:22
英文摘要	In 2016-2018, the ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) project undertook 3-month-long deployments to the southeastern (SE) Atlantic Ocean using research aircraft to better understand the impact of biomass burning (BB) aerosol transport to the SE Atlantic Ocean on climate. In this (part 1 of the meteorological overview) paper, the climatological features at monthly timescales are investigated. The southern African easterly jet (AEJ-S), defined as the zonal easterlies over 600-700 hPa exceeding 6 m s-1 around 5-15S, is a characteristic feature of the mid-level circulation over southern Africa that was also during the deployment months of August 2017, September 2016, and October 2018. Climatologically, the AEJ-S develops at lower altitudes (∼ 3 km; 700 hPa) between 5-10S in August, while it develops at around 4 km (∼ 600 hPa) and further south (5-15S) in September and October, largely driven by the strong sensible heating over the African plateau. Notable meteorological anomalous characteristics during the 3 deployment months, compared to climatology (2000-2018), include the following: (1) during August 2017, the AEJ-S was weaker than the climatological mean, with an additional anomalous upper-level jet aloft (∼ 6 km) around 10S. August 2017 was also drier over the SE Atlantic at 600-700 hPa than climatology, with a stronger Benguela low-level jet (LLJ) at 925-950 hPa along the Namibian coast of the SE Atlantic. Consistent with this, the southern Atlantic anticyclone was also stronger and closer to the coast than the August climatological mean. (2) During September 2016, the AEJ-S intensity was similar to the climatological mean, although the heat low and vertical motion over the land was slightly stronger compared to the September climatology. The LLJ and the large-scale southern Atlantic anticyclone were stronger than the climatological mean. (3) During October 2018, the AEJ-S was slightly weaker compared to the climatological mean, as was the LLJ and the southern Atlantic anticyclone. October 2018 was wetter over the Benguela coastal region at 600 hPa than the climatological mean. During all the deployment months, the sea surface temperatures (SST) over the SE Atlantic were warmer than the climatological means, but the monthly mean low cloud fraction was only noticeably reduced in August 2017. A weak August 2017 AEJ-S can explain low offshore black carbon (BC) mixing ratios within the European Centre for Medium-Range Weather Forecasts (ECMWF) Copernicus Atmosphere Monitoring Service (CAMS) reanalysis, although the BC peak altitude, at 2-3 km, is below that of the AEJ-S. The upper-level wave disturbance and the associated anomalous circulation also explain the weakening of AEJ-S through the reduction of the strength of the heat low over the land during August 2017. © 2021 Ju-Mee Ryoo et al.
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/246437
作者单位	Earth Science Division, NASA Ames Research Center, Moffett Field, CA, United States; Science and Technology Corporation, Moffett Field, CA, United States; Department of Atmospheric Sciences, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States; Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States; School of Meteorology, University of Oklahoma, Norman, OK, United States
推荐引用方式 GB/T 7714	Ryoo J.-M.,Pfister L.,Ueyama R.,et al. A meteorological overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the southeastern Atlantic during 2016-2018: Part 1 - Climatology[J],2021,21(22).
APA	Ryoo J.-M..,Pfister L..,Ueyama R..,Zuidema P..,Wood R..,...&Redemann J..(2021).A meteorological overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the southeastern Atlantic during 2016-2018: Part 1 - Climatology.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(22).
MLA	Ryoo J.-M.,et al."A meteorological overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the southeastern Atlantic during 2016-2018: Part 1 - Climatology".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.22(2021).