气候变化领域集成服务门户(CCPortal): Optical characterization of pure pollen types using a multi-wavelength Raman polarization lidar

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DOI	10.5194/acp-20-15323-2020
	Optical characterization of pure pollen types using a multi-wavelength Raman polarization lidar
	Shang X.; Giannakaki E.; Bohlmann S.; Filioglou M.; Saarto A.; Ruuskanen A.; Leskinen A.; Romakkaniemi S.; Komppula M.
发表日期	2020
ISSN	1680-7316
起始页码	15323
结束页码	15339
卷号	20 期号:23
英文摘要	We present a novel algorithm for characterizing the optical properties of pure pollen particles, based on the depolarization ratio values obtained in lidar measurements. The algorithm was first tested and validated through a simulator and then applied to the lidar observations during a 4- month pollen campaign from May to August 2016 at the European Aerosol Research Lidar Network (EARLINET) station in Kuopio (62°44′ N, 27°33′ E), in Eastern Finland. With a Burkard sampler, 20 types of pollen were observed and identified from concurrent measurements, with birch (Betula), pine (Pinus), spruce (Picea), and nettle (Urtica) pollen being the most abundant, contributing more than 90 % of the total pollen load, regarding number concentrations. Mean values of lidar-derived optical properties in the pollen layer were retrieved for four intense pollination periods (IPPs). Lidar ratios at both 355 and 532 nm ranged from 55 to 70 sr for all pollen types, without significant wavelength dependence. An enhanced depolarization ratio was found when there were pollen grains in the atmosphere, and an even higher depolarization ratio (with mean values of 0.25 or 0.14) was observed with the presence of the more non-spherical spruce or pine pollen. Under the assumption that the backscatterrelated Ångström exponent between 355 and 532 nm should be zero for pure pollen, the depolarization ratio of pure pollen particles at 532 nm was assessed, resulting in 0:24±0:01 and 0:36 ± 0:01 for birch and pine pollen, respectively. Pollen optical properties at 1064 and 355 nm were also estimated. The backscatter-related Ångström exponent between 532 and 1064 nm was assessed to be ∼ 0:8 (∼ 0:5) for pure birch (pine) pollen; thus the longer wavelength would be a better choice to trace pollen in the air. Pollen depolarization ratios of 0.17 and 0.30 at 355 nm were found for birch and pine pollen, respectively. The depolarization values show a wavelength dependence for pollen. This can be the key parameter for pollen detection and characterization. © 2020 Author(s).
英文关键词	algorithm; backscatter; computer simulation; concentration (composition); lidar; polarization; pollen; pollination; satellite data; satellite imagery; Betula; Urtica
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/168896
作者单位	Finnish Meteorological Institute, Atmospheric Research Centre of Eastern Finland, Kuopio, 70211, Finland; Department of Environmental Physics and Meteorology, University of Athens, Athens, Greece; Department of Applied Physics, University of Eastern Finland, Kuopio, 70211, Finland; Aerobiology Unit, University of Turku, Turku, Finland
推荐引用方式 GB/T 7714	Shang X.,Giannakaki E.,Bohlmann S.,et al. Optical characterization of pure pollen types using a multi-wavelength Raman polarization lidar[J],2020,20(23).
APA	Shang X..,Giannakaki E..,Bohlmann S..,Filioglou M..,Saarto A..,...&Komppula M..(2020).Optical characterization of pure pollen types using a multi-wavelength Raman polarization lidar.Atmospheric Chemistry and Physics,20(23).
MLA	Shang X.,et al."Optical characterization of pure pollen types using a multi-wavelength Raman polarization lidar".Atmospheric Chemistry and Physics 20.23(2020).