Evolution of planetary boundary layer under different weather conditions, and its impact on aerosol concentrations--颗粒学报PARTICUOLOGY

Quan, J., Gao, Y., Zhang, Q., Tie, X., Cao, J., Han, S., Meng, J., Chen, P., & Zhao, D. (2013). Evolution of planetary boundary layer under different weather conditions, and its impact on aerosol concentrations. Particuology, 11(1), 34–40. https://doi.org/10.1016/j.partic.2012.04.005

Evolution of planetary boundary layer under different weather conditions, and its impact on aerosol concentrations

Jiannong Quan ^{a b}, Yang Gao ^a, Qiang Zhang ^a, Xuexi Tie ^{c d *}, Junji Cao ^c, Suqin Han ^e, Junwang Meng ^a, Pengfei Chen ^a, Delong Zhao ^a

a Beijing Weather Modification Office, Beijing, China
b Institude of Urban Meteorology, CMA, Beijing, China
c Key Laboratory of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xian, China
d National Center for Atmospheric Research, Boulder, USA
e Tianjin Institute of Meteorological Sciences, Tianjin, China

10.1016/j.partic.2012.04.005

Volume 11, Issue 1, February 2013, Pages 34-40

Received 9 January 2012, Revised 2 April 2012, Accepted 26 April 2012, Available online 6 July 2012.

E-mail: xxtie@ucar.edu

Highlights

► Planetary boundary layer (PBL) heights were determined by three remote sensing instruments from September 9–30, 2010 at Tianjin, China.

► The averaged PBL height was about 1000–1300 m during noon/afternoon-time, and 200–300 m during night-time.

► PBL height and aerosol concentration were anti-correlated during clear and haze conditions. Feedback between PBL height and aerosol loading may exist.

Abstract

A field experiment was conducted in Tianjin, China from September 9–30, 2010, focused on the evolution of Planetary Boundary Layer (PBL) and its impact on surface air pollutants. The experiment used three remote sensing instruments, wind profile radar (WPR), microwave radiometer (MWR) and micro-pulse lidar (MPL), to detect the vertical profiles of winds, temperature, and aerosol backscattering coefficient and to measure the vertical profiles of surface pollutants (aerosol, CO, SO₂, NO_x), and also collected sonic anemometers data from a 255-m meteorological tower. Based on these measurements, the evolution of the PBL was estimated. The averaged PBL height was about 1000–1300 m during noon/afternoon-time, and 200–300 m during night-time. The PBL height and the aerosol concentrations were anti-correlated during clear and haze conditions. The averaged maximum PBL heights were 1.08 and 1.70 km while the averaged aerosol concentrations were 52 and 17 μg/m³ under haze and clear sky conditions, respectively. The influence of aerosols and clouds on solar radiation was observed based on sonic anemometers data collected from the 255-m meteorological tower. The heat flux was found significantly decreased by haze (heavy pollution) or cloud, which tended to depress the development of PBL, while the repressed structure of PBL further weakened the diffusion of pollutants, leading to heavy pollution. This possible positive feedback cycle (more aerosols → lower PBL height → more aerosols) would induce an acceleration process for heavy ground pollution in megacities.

Graphical abstract

Keywords

Planetary boundary layer (PBL); Interaction between the PBL and aerosols

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