Surface Meteorological Conditions and Boundary Layer Height Variations During an Air Pollution Episode in Nanjing, China

2019 ◽  
Vol 124 (6) ◽  
pp. 3350-3364 ◽  
Author(s):  
J. Yin ◽  
C. Y. Gao ◽  
J. Hong ◽  
Z. Gao ◽  
Y. Li ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Meteorological Conditions ◽  
Layer Height ◽  
Boundary Layer Height ◽  
Pollution Episode

The difference in the boundary layer height between urban and suburban areas in Beijing and its implications for air pollution

2021 ◽  
pp. 118552
Author(s):  
Meng Wang ◽  
Guiqian Tang ◽  
Yusi Liu ◽  
Minjin Ma ◽  
Miao Yu ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Layer Height ◽  
Boundary Layer Height ◽  
Suburban Areas ◽  
The Difference

scholarly journals Technical note: Boundary layer height determination from Lidar for improving air pollution episode modelling: development of new algorithm and evaluation

2017 ◽  
Author(s):  
Ting Yang ◽  
Zifa Wang ◽  
Wei Zhang ◽  
Alex Gbaguidi ◽  
Nubuo Sugimoto ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
High Performance ◽  
Accurate Determination ◽  
Technical Note ◽  
Strong Increase ◽  
Layer Height ◽  
Boundary Layer Height ◽  
Retrieval Algorithms ◽  
The Impact

Abstract. Predicting air pollution events in low atmosphere over megacities requires thorough understanding of the tropospheric dynamic and chemical processes, involving notably, continuous and accurate determination of the boundary layer height (BLH). Through intensive observations experimented over Beijing (China), and an exhaustive evaluation existing algorithms applied to the BLH determination, persistent critical limitations are noticed, in particular over polluted episodes. Basically, under weak thermal convection with high aerosol loading, none of the retrieval algorithms is able to fully capture the diurnal cycle of the BLH due to pollutant insufficient vertical mixing in the boundary layer associated with the impact of gravity waves on the tropospheric structure. Subsequently, a new approach based on gravity wave theory (the cubic root gradient method: CRGM), is developed to overcome such weakness and accurately reproduce the fluctuations of the BLH under various atmospheric pollution conditions. Comprehensive evaluation of CRGM highlights its high performance in determining BLH from Lidar. In comparison with the existing retrieval algorithms, the CRGM potentially reduces related computational uncertainties and errors from BLH determination (strong increase of correlation coefficient from 0.44 to 0.91 and significant decrease of the root mean square error from 643 m to 142 m). Such newly developed technique is undoubtedly expected to contribute to improve the accuracy of air quality modelling and forecasting systems.

scholarly journals Relationships between the planetary boundary layer height and surface pollutants derived from lidar observations over China

2018 ◽  
Author(s):  
Tianning Su ◽  
Zhanqing Li ◽  
Ralph Kahn
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Negative Correlation ◽  
North China Plain ◽  
North China ◽  
Planetary Boundary Layer Height ◽  
Layer Height ◽  
Boundary Layer Height ◽  
The North ◽  
The North China Plain

Abstract. The frequent occurrence of severe air pollution episodes in China has raised great concerns with the public and scientific communities. Planetary boundary layer height (PBLH) is a key factor in the vertical mixing and dilution of near-surface pollutants. However, the relationship between PBLH and surface pollutants, especially particulate matter (PM) concentration, across the whole of China, is not yet well understood. We investigate this issue at ~ 1500 surface stations using PBLH derived from space-borne and ground-based lidar, and discuss the influence of topography and meteorological variables on the PBLH-PM relationship. A generally negative correlation is observed between PM and the PBLH, albeit varying greatly in magnitude with location and season. Correlations are much weaker over the highlands than plains regions, which may be associated with lower pollution levels and mountain breezes. The influence of horizontal transport on surface PM is considered as well, manifested as a negative correlation between surface PM and wind speed over the whole nation. Strong wind with clean upwind sources plays a dominant role in removing pollutants, and leads to weak PBLH-PM correlation. A ventilation rate is introduced to jointly consider horizontal and vertical dispersion, which has the largest impact on surface pollutant accumulation over the North China Plain. Aerosol absorption feedbacks also appear to affect the PBLH-PM relationship, as revealed via comparing air pollution in Beijing and Hong Kong. Absorbing aerosols in high concentrations likely contribute to the significant PBLH-PM correlation over the North China Plain (e.g., during winter). As major precursor emissions for secondary aerosols, sulfur dioxide, nitrogen dioxide, and carbon monoxide have similar negative responses to increased PBLH, whereas ozone is positively correlated with PBLH over most regions, which may be caused by heterogeneous reactions and photolysis rates.

scholarly journals Ceilometer Monitoring of Boundary-Layer Height and Its Application in Evaluating the Dilution Effect on Air Pollution

2019 ◽  
Vol 172 (3) ◽  
pp. 435-455 ◽  
Author(s):  
Junhong Lee ◽  
Je-Woo Hong ◽  
Keunmin Lee ◽  
Jinkyu Hong ◽  
Erik Velasco ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Dilution Effect ◽  
Layer Height ◽  
Boundary Layer Height

scholarly journals Relationships between the planetary boundary layer height and surface pollutants derived from lidar observations over China: regional pattern and influencing factors

2018 ◽  
Vol 18 (21) ◽  
pp. 15921-15935 ◽  
Author(s):  
Tianning Su ◽  
Zhanqing Li ◽  
Ralph Kahn
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Planetary Boundary Layer ◽  
North China Plain ◽  
North China ◽  
Strong Wind ◽  
Planetary Boundary Layer Height ◽  
Near Surface ◽  
Layer Height ◽  
Boundary Layer Height

Abstract. The frequent occurrence of severe air pollution episodes in China has been a great concern and thus the focus of intensive studies. Planetary boundary layer height (PBLH) is a key factor in the vertical mixing and dilution of near-surface pollutants. However, the relationship between PBLH and surface pollutants, especially particulate matter (PM) concentration across China, is not yet well understood. We investigate this issue at ∼1600 surface stations using PBLH derived from space-borne and ground-based lidar, and discuss the influence of topography and meteorological variables on the PBLH–PM relationship. Albeit the PBLH–PM correlations are roughly negative for most cases, their magnitude, significance, and even sign vary considerably with location, season, and meteorological conditions. Weak or even uncorrelated PBLH–PM relationships are found over clean regions (e.g., Pearl River Delta), whereas nonlinearly negative responses of PM to PBLH evolution are found over polluted regions (e.g., North China Plain). Relatively strong PBLH–PM interactions are found when the PBLH is shallow and PM concentration is high, which typically corresponds to wintertime cases. Correlations are much weaker over the highlands than the plains regions, which may be associated with lighter pollution loading at higher elevations and contributions from mountain breezes. The influence of horizontal transport on surface PM is considered as well, manifested as a negative correlation between surface PM and wind speed over the whole nation. Strong wind with clean upwind air plays a dominant role in removing pollutants, and leads to obscure PBLH–PM relationships. A ventilation rate is used to jointly consider horizontal and vertical dispersion, which has the largest impact on surface pollutant accumulation over the North China Plain. As such, this study contributes to improved understanding of aerosol–planetary boundary layer (PBL) interactions and thus our ability to forecast surface air pollution.

Boundary layer height determination from lidar for improving air pollution episode modeling: development of new algorithm and evaluation

2020 ◽  
Author(s):  
Ting Yang ◽  
zifa wang ◽  
wei zhang ◽  
Alex Gbaguidi ◽  
Nobuo Sugimoto
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
High Performance ◽  
Accurate Determination ◽  
Wave Theory ◽  
Strong Increase ◽  
Layer Height ◽  
Boundary Layer Height ◽  
Retrieval Algorithms ◽  
The Impact

<p><span><span>Predicting air pollution events in the low atmosphere over megacities requires a thorough understanding of the tropospheric dynamics and chemical processes, involving, notably, continuous and accurate determination of the boundary layer height (BLH). Through intensive observations experimented over Beijing (China) and an exhaustive evaluation of existing algorithms applied to the BLH determination, persistent critical limitations are noticed, in particular during polluted episodes. Basically, under weak thermal convection with high aerosol loading, none of the retrieval algorithms is able to fully capture the diurnal cycle of the BLH due to insufficient vertical mixing of pollutants in the boundary layer associated with the impact of gravity waves on the tropospheric structure. Consequently, a new approach based on gravity wave theory (the cubic root gradient method: CRGM) is developed to overcome such weakness and accurately reproduce the fluctuations of the BLH under various atmospheric pollution conditions. Comprehensive evaluation of CRGM highlights its high performance in determining BLH from lidar. In comparison with the existing retrieval algorithms, CRGM potentially reduces related computational uncertainties and errors from BLH determination (strong increase of correlation coefficient from 0.44 to 0.91 and significant decreases of the root mean square error from 643 to 142 m). Such a newly developed technique is undoubtedly expected to contribute to improving the accuracy of air quality modeling and forecasting systems.</span></span></p>

Urban air pollution modelling and measurements of boundary layer height

2007 ◽  
Vol 41 (19) ◽  
pp. 4040-4049 ◽  
Author(s):  
F. Davies ◽  
D.R. Middleton ◽  
K.E. Bozier
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Urban Air Pollution ◽  
Urban Air ◽  
Air Pollution Modelling ◽  
Layer Height ◽  
Boundary Layer Height

scholarly journals Observational Analysis of Aerosol–Meteorology Interactions for the Severe Haze Episode in Korea

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 33
Author(s):  
Seung-Hee Eun ◽  
Sung-Min Park ◽  
Byung-Gon Kim ◽  
Jin-Soo Park ◽  
Ki-Ho Chang
Keyword(s):  
Boundary Layer ◽  
Reanalysis Data ◽  
Cloud Fraction ◽  
Meteorological Conditions ◽  
Short Term ◽  
Layer Height ◽  
Boundary Layer Height ◽  
Haze Episode ◽  
Light Precipitation ◽  
Haze Days

Korea has occasionally suffered from various kinds of severe hazes such as long-range transported aerosol (LH), yellow sand (YS), and urban haze (UH). We classified haze days into LH, YS, and UH and analyzed the characteristics of its associated meteorological conditions for 2011–2016 using reanalysis data and surface observations. The results show that higher boundary layer height and stronger wind speed were found for the LH and YS hazes relative to those for UH. Intensive analysis on a golden episode of 10–18 January 2013 indicates that the cloud fraction increased along with extended light precipitation at a weaker rate by enhanced aerosol loading for an unprecedented LH event, which in turn brought about a decrease in boundary layer height (BLH) with less irradiance, that is, much stronger stability. Later, the intensified stability after the LH event accumulated and increased domestic aerosols, and eventually resulted in the longer-lasting severe haze. This study suggests that aerosol–meteorology interactions play an important role in both short-term weather and fine particle forecasts, especially on polluted days.

Sign in / Sign up

Export Citation Format

Share Document