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DOI	10.5194/acp-22-11823-2022
	The effect of clouds and precipitation on the aerosol concentrations and composition in a boreal forest environment
	Isokaanta, Sini; Kim, Paul; Mikkonen, Santtu; Kuhn, Thomas; Kokkola, Harri; Yli-Juuti, Taina; Heikkinen, Liine; Luoma, Krista; Petaja, Tuukka; Kipling, Zak; Partridge, Daniel; Virtanen, Annele
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	11823
结束页码	11843
卷号	22 期号:17 页码:21
英文摘要	Atmospheric aerosol particle concentrations are strongly affected by various wet processes, including below and in-cloud wet scavenging and in-cloud aqueous-phase oxidation. We studied how wet scavenging and cloud processes affect particle concentrations and composition during transport to a rural boreal forest site in northern Europe. For this investigation, we employed air mass history analysis and observational data. Long-term particle number size distribution (similar to 15 years) and composition measurements (similar to 8 years) were combined with air mass trajectories with relevant variables from reanalysis data. Some such variables were rainfall rate, relative humidity, and mixing layer height. Additional observational datasets, such as temperature and trace gases, helped further evaluate wet processes along trajectories with mixed effects models. All chemical species investigated (sulfate, black carbon, and organics) exponentially decreased in particle mass concentration as a function of accumulated precipitation along the air mass route. In sulfate (SO4) aerosols, clear seasonal differences in wet removal emerged, whereas organics (Org) and equivalent black carbon (eBC) exhibited only minor differences. The removal efficiency varied slightly among the different reanalysis datasets (ERA-Interim and Global Data Assimilation System; GDAS) used for the trajectory calculations due to the difference in the average occurrence of precipitation events along the air mass trajectories between the reanalysis datasets. Aqueous-phase processes were investigated by using a proxy for air masses travelling inside clouds. We compared air masses with no experience of approximated in-cloud conditions or precipitation during the past 24 h to air masses recently inside non-precipitating clouds before they entered SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations). Significant increases in SO4 mass concentration were observed for the latter air masses (recently experienced non-precipitating clouds). Our mixed effects model considered other contributing factors affecting particle mass concentrations in SMEAR II: examples were trace gases, local meteorology, and diurnal variation. This model also indicated in-cloud SO4 production. Despite the reanalysis dataset used in the trajectory calculations, aqueous-phase SO4 formation was observed. Particle number size distribution measurements revealed that most of the in-cloud SO4 formed can be attributed to particle sizes larger than 200 nm (electrical mobility diameter). Aqueous-phase secondary organic aerosol (aqSOA) formation was non-significant.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000853013000001
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/273675
作者单位	University of Eastern Finland; University of Exeter; University of Eastern Finland; Finnish Meteorological Institute; University of Helsinki; Stockholm University; Stockholm University; European Centre for Medium-Range Weather Forecasts (ECMWF); Finnish Meteorological Institute
推荐引用方式 GB/T 7714	Isokaanta, Sini,Kim, Paul,Mikkonen, Santtu,et al. The effect of clouds and precipitation on the aerosol concentrations and composition in a boreal forest environment[J],2022,22(17):21.
APA	Isokaanta, Sini.,Kim, Paul.,Mikkonen, Santtu.,Kuhn, Thomas.,Kokkola, Harri.,...&Virtanen, Annele.(2022).The effect of clouds and precipitation on the aerosol concentrations and composition in a boreal forest environment.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(17),21.
MLA	Isokaanta, Sini,et al."The effect of clouds and precipitation on the aerosol concentrations and composition in a boreal forest environment".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.17(2022):21.