Development of a 3D Real-Time Atmospheric Monitoring System (3DREAMS) Using Doppler LiDARs and Applications for Long-Term Analysis and Hot-and-Polluted Episodes

Steve Hung Lam Yim

doi:10.3390/rs12061036

Abstract

Heatwaves and air pollution are serious environmental problems that adversely affect human health. While related studies have typically employed ground-level data, the long-term and episodic characteristics of meteorology and air quality at higher altitudes have yet to be fully understood. This study developed a 3-Dimensional Real-timE Atmospheric Monitoring System (3DREAMS) to measure and analyze the vertical profiles of horizontal wind speed and direction, vertical wind velocity as well as aerosol backscatter. The system was applied to Hong Kong, a highly dense city with complex topography, during each season and including hot-and-polluted episodes (HPEs) in 2019. The results reveal that the high spatial wind variability and wind characteristics in the lower atmosphere in Hong Kong can extend upwards by up to 0.66 km, thus highlighting the importance of mountains for the wind environment in the city. Both upslope and downslope winds were observed at one site, whereas downward air motions predominated at another site. The high temperature and high concentration of fine particulate matter during HPEs were caused by a significant reduction in both horizontal and vertical wind speeds that established conditions favorable for heat and air pollutant accumulation, and by the prevailing westerly wind promoting transboundary air pollution. The findings of this study are anticipated to provide valuable insight for weather forecasting and air quality studies. The 3DREAMS will be further developed to monitor upper atmosphere wind and air quality over the Greater Bay Area of China.

Highlights

Heatwaves and air pollution are major environmental problems [1,2,3,4] that adversely affect human health [5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]
This study developed the 3-Dimensional Real-timE Atmospheric Monitoring System (3DREAMS) to measure the long-term vertical profiles of horizontal wind speed and direction and vertical wind velocity and aerosol backscatter in a highly dense city with complex topography
The vertical profiles of nine identified hot-and-polluted episodes (HPEs) were analyzed to assess the influences of horizontal wind speed and direction and vertical wind velocity on heat and aerosol accumulation

Summary

Introduction

Heatwaves and air pollution are major environmental problems [1,2,3,4] that adversely affect human health [5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]. Data concerning the wind and air quality in the upper atmosphere are required for data analyses and modeling. This absence of data limits research into heatwaves and air pollution. Lee et al [20] investigated a period of abnormally high temperatures and air pollution in the United Kingdom. They determined that the regional entrainment of air from the upper atmosphere caused early morning increases in ozone during the episode and increased biogenic emissions under high temperatures. A more comprehensive understanding of the formation mechanism of such episodes is required

Methods

Results

Conclusion