Ambient particle characteristics by single particle aerosol mass spectrometry at a coastal site in Hong Kong: a case study affected by the sea-land breeze

PeerJ

article

Nana Wang¹  Yanjing Zhang¹  Lei Li²  Houwen Wang¹  Yunhui Zhao¹  Guanru Wu¹  Mei Li²  Zhen Zhou²  Xinfeng Wang³  Jian Zhen Yu⁴  Yang Zhou¹ 

[1] College of Oceanic and Atmospheric Sciences, Ocean University of Qingdao;Institute of Atmospheric Environment Safety and Pollution Control, Jinan University;Environment Research Institute, Shandong University;Division of Environment, Hong Kong University of Science and Technology;Department of Chemistry, Hong Kong University of Science and Technology

关键词: Single-particle;    Sea-land breeze;    Regional transportation;    Air quality;    Coastal site;   

DOI  :  10.7717/peerj.14116

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The sea-land breeze (SLB) circulation plays a vital role in the transport of atmospheric pollutants in coastal cities. In this study, a single particle aerosol mass spectrometer (SPAMS) and combined bulk aerosol instruments were deployed to investigate the ambient particle characteristic at a suburban coastal site in Hong Kong from February 22 to March 10, 2013. Significant SLB circulations were captured from March 6–10, 2013, during the campaign. During the SLB periods, air quality worsened, with PM2.5 concentrations reaching a peak of 55.6 μg m−3 and an average value of 42.8 ± 4.5 μg m−3. A total of 235,894 particles were measured during the SLB stage. Eight major sources were identified by investigating the mixing states of the total particles, including the coal-burning related particles (48.1%), biomass burning particles (6.7%), vehicle emission-related particles (16.4%), sea salt (9.2%), ship emission particles (2.7%), dust/steeling industries (3.7%), waste incineration (6.3%), and road dust (3.9%). It was noteworthy that the PM2.5 concentrations and particle numbers increased sharply during the transition of land wind to the sea breeze. Meanwhile, the continental sourced pollutants recirculated back to land resulting in a cumulative increase in pollutants. Both individual and bulk measurements support the above results, with high contributions from coal burning, biomass burning, bulk K+, and NO3−, which were probably from the regional transportation from the nearby area. In contrast, the ship and vehicle emissions increased during the SLB period, with a high sulfate concentration partially originating from the ship emission. In this study, field evidence of continental-source pollutants backflow to land with the evolution of sea breeze was observed and helped our current understanding of the effect of SLB on air quality in the coastal city.

【 授权许可】

CC BY