Comparison of Aerosol optical depth (AOD) derived from AERONET sunphotometer and Lidar system

Khor, Wei Ying; Hee, Wan Shen; Tan, Fuyi; Lim, H. S.; Jafri, Mohd Zubir Mat; Holben, B. N.

doi:10.1088/1755-1315/20/1/012058

Cited by 11 publications

(7 citation statements)

References 10 publications

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“…AOD (AAOD) is the measure of aerosols (absorbing aerosols) distributed within a column of air from the surface to the top of the atmosphere (Khor et al, 2014). coefficient of 0.89.…”

Section: Aod and Aaodmentioning

confidence: 99%

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM2.5 concentrations in Beijing during severe haze events

et al. 2022

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Abstract. Vertical profiles of black carbon (BC) play a critical role in modifying the meteorological conditions such as temperature, planetary boundary layer height (PBLH), and regional circulation, which influence surface layer concentrations of PM2.5 (particulate matter with a diameter of 2.5 µm or less; the surface layer covers from 0 to 79.5 m). However, BC vertical profiles in current models usually have large uncertainties. In this study, by using measurements of BC vertical profiles in Beijing collected by King Air 350 aircraft and the Weather Research and Forecasting with Chemistry model (WRF-Chem) coupled with an improved integrated process (IPR) analysis scheme, we investigated the direct radiative effect (DRE) of BC with different vertical profiles on meteorology and PM2.5 concentrations in Beijing during two severe haze events (11–12 and 16–19 December 2016). Compared with measurements in Beijing, the model overestimated BC concentrations by 87.4 % at the surface and underestimated BC mass by 14.9 % at altitudes of 300–900 m as averaged over the two pollution events. The BC DRE with the default vertical profiles from the model heated the air around 300 m altitude, but the warming would be stronger when BC vertical profiles were modified for each day using the observed data during the two severe haze events. Accordingly, compared to the simulation with the default vertical profiles of BC, PBLH was reduced further by 24.7 m (6.7 %) and 6.4 m (3.8 %) in Beijing in the first and second haze events, respectively, with the modified vertical profiles, and hence the surface layer PM2.5 concentrations were higher by 9.3 µg m−3 (4.1 %) and 5.5 µg m−3 (3.0 %) over central Beijing, owing to increased positive contributions of vertical mixing and chemical processes. Furthermore, we quantified by sensitivity experiments the roles of BC vertical profiles with six exponential decline functions (C(h)=C0×e-h/hs and hs = 0.35, 0.48, 0.53, 0.79, 0.82, and 0.96) parameterized on the basis of the observations. A larger hs means less BC at the surface and more BC in the upper atmosphere, resulting in less solar radiation reaching the ground and consequently a stronger cooling at the surface (+0.21 with hs of 0.35 vs. −0.13∘ with hs of 0.96). Our results indicate that it is very important to have accurate vertical profiles of BC in simulations of meteorology and PM2.5 concentrations during haze events.

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“…AOD (AAOD) is the measure of aerosols (absorbing aerosols) distributed within a column of air from the surface to the top of the atmosphere (Khor et al, 2014). coefficient of 0.89.…”

Section: Aod and Aaodmentioning

confidence: 99%

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM2.5 concentrations in Beijing during severe haze events

et al. 2022

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“…AOD (AAOD) is the measure of aerosols (absorbing aerosols) distributed within a column of air from the surface to the top of the atmosphere (Khor et al, 2014). Figure S3 shows the horizontal spatial distributions of observed and simulated AOD at 550 nm over the NCP averaged over 11-19 December 2016.…”

Section: Aod and Aaodmentioning

confidence: 99%

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM2.5 concentrations in Beijing during severe haze events

Chen

Liao

Yang

et al. 2021

Preprint

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Abstract. Vertical profiles of black carbon (BC) play a critical role in BC-meteorology interaction which influences PM2.5 (particulate matter with a diameter of 2.5 μm or less) concentrations. In this study, we used the Weather Research and Forecasting with Chemistry model (WRF-Chem) coupled with an improved integrated process (IPR) analysis scheme to investigate the direct radiative effect (DRE) of BC with different vertical profiles on meteorology and PM2.5 concentrations in Beijing during two severe haze events (11–12 December 2016 and 16–19 December 2016). The vertical profiles of BC in Beijing collected by King-Air350 aircraft can be classified into two types: the first type was characterized by decreases in BC concentration with altitude, which was the case mainly controlled by local emissions; the second type had maximum BC concentration around 900 hPa, which was mainly affected by regional transport from the polluted south/southwest region. Compared with measurements in Beijing, the model overestimated BC concentrations by 87.4 % at the surface and underestimated BC mass by 14.9 % at altitudes of 300–900 m altitude as averaged over the two pollution events. The BC DRE with the default vertical profiles from the model heated the air around 300 m altitude but the warming would be stronger when BC vertical profiles were modified for each day using observed data during the two severe haze events. Accordingly, compared to the simulation with the default vertical profiles of BC, planetary boundary layer heights (PBLH) were reduced further by 24.7 m (6.7 %) and 6.4 m (3.8 %) in Beijing and simulated PM2.5 concentrations were higher by 9.3 μg m−3 (4.1 %) and 5.5 μg m−3 (3.0 %) over central Beijing in the first and second haze events, respectively, with modified vertical profiles. Furthermore, we quantified by sensitivity experiments the roles of BC vertical profiles with six exponential decline functions (C(h) = C0 × e−h/hs and hs = 0.35, 0.48, 0.53, 0.79, 0.82 and 0.96) parameterized on the basis of the observations and the vertical profile dominated by regional transport. A larger hs leads to a sharper decline of BC concentrations with altitude (less BC at the surface and more BC in the upper atmosphere), resulting in a stronger cooling at the surface (+0.21 with hs of 0.35 vs. −0.13 °C with hs of 0.96) and hence larger reductions in PBLH (larger BC-induced increases in PM2.5). Relative to the simulation without BC DRE, the mean PM2.5 concentrations were increased by 5.5 μg m−3 (3.4 %) and 7.9 μg m−3 (4.9 %) with BC DRE when hs values were 0.35 and 0.96, respectively. Our results indicate that it is very important to have accurate vertical profiles of BC in simulations of meteorology and PM2.5 concentrations during haze events.

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“…Typically, it can take between 2-7 days for visibility to return to normal background conditions, depending upon atmospheric, meteorological and topographical conditions. Satellite measured Aerosol Optical Depth (AOD), a measure of PM quantity distributed within a column of air from the Earth's surface to the top of the atmosphere, can also be used to understand and investigate the effect of fireworks on visibility and air quality (Kessner et al, 2013;Khor et al, 2014;Pope et al, 2016;Wu et al, 2014;Zheng et al, 2017). Devara et al (2015) reported an approximately four-fold increase in AOD values during the Diwali festival in India.…”

Section: Visibilitymentioning

confidence: 99%

Air quality during and after festivals: Aerosol concentrations, composition and health effects

Singh

Pant

Pope

2019

Atmospheric Research

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Comparison of Aerosol optical depth (AOD) derived from AERONET sunphotometer and Lidar system

Cited by 11 publications

References 10 publications

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM<sub>2.5</sub> concentrations in Beijing during severe haze events

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM<sub>2.5</sub> concentrations in Beijing during severe haze events

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM<sub>2.5</sub> concentrations in Beijing during severe haze events

Air quality during and after festivals: Aerosol concentrations, composition and health effects

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Comparison of Aerosol optical depth (AOD) derived from AERONET sunphotometer and Lidar system

Cited by 11 publications

References 10 publications

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations in Beijing during severe haze events

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations in Beijing during severe haze events

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations in Beijing during severe haze events

Air quality during and after festivals: Aerosol concentrations, composition and health effects

Contact Info

Product

Resources

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Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM<sub>2.5</sub> concentrations in Beijing during severe haze events

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM<sub>2.5</sub> concentrations in Beijing during severe haze events

Simulated impacts of vertical distributions of black carbon aerosol on meteorology and PM<sub>2.5</sub> concentrations in Beijing during severe haze events