Journal of Geo-information Science ›› 2020, Vol. 22 ›› Issue (7): 1532-1543.doi: 10.12082/dqxxkx.2020.190360

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Spatiotemporal Dynamics and Tracing of Aerosol over Hainan Island

GAO Wangwang1,4(), FENG Jianzhong2, BAI Linyan3,4,*(), YANG Jianhua1, GUO Leifeng2, LI Hualin4, CUI Mengrui4   

  1. 1. School of Geological Engineering and Geomatics, Chang'an University, Xi'an 710054, China;
    2. Agricultural Information Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
    3. Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China;
    4. Hainan Earth Observation Laboratory, Sanya 572029, China
  • Received:2019-07-08 Revised:2019-11-29 Online:2020-07-25 Published:2020-09-25
  • Contact: BAI Linyan E-mail:gww_9527@163.com;baily@aircas.ac.cn
  • Supported by:
    Supported by the Strategic Type A Pilot Project of Chinese Academy of Scienc(XDA19030302);Major Science and Technology Planning Projects of Hainan Province(ZDKJ2016021);National Natural Science Foundation of China(31671588)

Abstract:

To serve as a basis for atmospheric environmental quality monitoring and pollution prevention & control in Hainan, which located in a specific geographical position with great strategic significance and national development potentiality, it is imperative to reveal the spatiotemporal dynamics patterns of aerosol over Hainan Island and clarify the sources of atmospheric pollutants. Hence, this study aims to investigate the spatiotemporal dynamics characteristics of the Aerosol Optical Depth (AOD) over Hainan Island by using the MODIS 3 km spatial resolution data (i.e., MOD04_3K product) from 2003 to 2017. Then, we calculated the 48-h backward trajectories at three above ground levels (10, 500, and 1000 m) of eight typical air pollution events in Haikou city, the capital and largest city of Hainan Province and the starting point to trace the sources of air pollutants in the region, by using the Hybrid Single Particle Lagrangian Integrated Trajectory(HYSPLIT) model. The results indicated that: (1) The average values of AODs during 2003-2017 over Hainan Island region exhibited a notable three-stage stepped-down spatial distribution from northwest to southeast, each of which displayed some distinctly spatial variations. (2) During the fifteen-year period, a slight increase tendency of the annual mean values of AODs was noted with their total mean value of 0.095 over Hainan Island, and the seasonal mean values of AODs were characterized with “spring > autumn > winter > summer”, the reasons for which could be derived from the common influences of regional weather systems and local winds, as well as the atmospheric pollutant emissions caused by tourism development. (3) In addition, during periods of typical atmospheric pollution events in Hainan Island (Haikou) from 2013 to 2017, the backward trajectories of air pollutants at three ground levels (10, 500, and 1000m) were primarily from the northeast direction of Hainan Island. Thus, the air pollutants originated from the mainland in the northeast direction such as the Pearl River Delta region were brought to Hainan Island along land tracks or coastal belts by the prevailing northeast winds; the plausible explanation of this could be that the atmospheric pollution events in Haikou occurred because of the joint effects of regional weather (e.g., continental cold high pressure) and local weather (e.g., sea-breeze convergence) systems. Perhaps, findings of this study could contribute to the understanding and assessing dynamic changes of the atmospheric environmental quality situation over decade in Hainan Island region and provide useful references for the establishment of joint prevention and control mechanism for air pollution.

Key words: Aerosol Optical Depth (AOD), PM2.5, atmospheric environment, spatiotemporal dynamics, remote sensing, HYSPLIT model, Trace, Hainan Island