气候变化领域集成服务门户(CCPortal): In situ vertical characteristics of optical properties and heating rates of aerosol over Beijing

CCPortal

DOI	10.5194/acp-20-2603-2020
	In situ vertical characteristics of optical properties and heating rates of aerosol over Beijing
	Tian P.; Liu D.; Zhao D.; Yu C.; Liu Q.; Huang M.; Deng Z.; Ran L.; Wu Y.; Ding S.; Hu K.; Zhao G.; Zhao C.; Ding D.
发表日期	2020
ISSN	16807316
起始页码	2603
结束页码	2622
卷号	20 期号:4
英文摘要	Characterizing vertical profiles of aerosol optical properties is important because relying on only the surface or column-integrated measurements cannot unambiguously constrain the radiative impacts of aerosol. This study presents series of vertical profiles of in situ measured multi-wavelength optical properties of aerosols during three pollution events from November to December 2016 over the Beijing region. For all pollution events, the clean periods (CPs) before pollution initialization showed a higher scattering Ångström exponent (SAE) and a smaller asymmetry parameter (g) with relatively uniform vertical structures. The heavy pollution periods (HPs) showed an increased particle size, causing these parameters to vary in the opposite way. During the transition periods (TPs), regional transport of aged aerosols at higher altitudes was found. The Aerosol Robotic Network (AERONET) aerosol optical depth (AOD) matched the in situ measurements within 10 %; however the AERONET absorption optical depth (AAOD) was 10 %-200 % higher than the in situ measurements, and this positive discrepancy increased to 30 % at shorter wavelengths. The absorption of brown carbon (BrC) was identified by the increased-absorption Ångström exponent (AAE), and the heating rate of black carbon (BC) and BrC was estimated by computing the spectral absorption coefficient and actinic flux calculated by a radiative transfer model. BC and BrC had a heating rate of up to 0.18 and 0.05 K h-1 in the planetary boundary layer (PBL), respectively, during the pollution period. The fraction of BrC absorption increased from 12 % to 40 % in the PBL from the CP to the HP. Notably, a higher contribution of BrC heating was found above the PBL under polluted conditions. This study paints a full picture of shortwave heating impacts of carbonaceous aerosols during different stages of pollution events and highlights the increased contribution of BrC absorption especially at higher altitudes during pollution. © Author(s) 2020.
关键词	aerosol atmospheric pollution heating in situ measurement optical property vertical profile wavelength Beijing [China]China
语种	英语
来源机构	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/132195
推荐引用方式 GB/T 7714	Tian P.,Liu D.,Zhao D.,et al. In situ vertical characteristics of optical properties and heating rates of aerosol over Beijing[J]. Atmospheric Chemistry and Physics,2020,20(4).
APA	Tian P..,Liu D..,Zhao D..,Yu C..,Liu Q..,...&Ding D..(2020).In situ vertical characteristics of optical properties and heating rates of aerosol over Beijing.,20(4).
MLA	Tian P.,et al."In situ vertical characteristics of optical properties and heating rates of aerosol over Beijing".20.4(2020).