Evaluating the Effects of Springtime Dust Storms over Beijing and the Associated Characteristics of Sub-Micron Aerosol

Abstract

In order to understand the characteristics, sources and processes of non-refractory submicron particles (NR-PM 1 ), an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed to acquire observational data during the spring (April 1 to 30) in Beijing, China, in 2012. Based on PM 10 , PM 2.5 and NR-PM 1 mass concentrations observation, satellite images and the back trajectory analysis, one haze and dust storm episodes were recorded during the campaign, in addition, one clean episodes was also added to the comparison as a reference. The NR-PM 1 mass concentration was 97 µg m -3 during the haze episodes, while it was approximately 12 times and 1.7 times that on the clean and dust episodes, respectively. In addition, the secondary inorganic aerosol (sulfate, nitrate and ammonium) contributed the largest fraction of NR-PM 1 (69%) during the haze episodes. The dust storms originated from the northwestern caused the PM 10 peaking at 826 µg m ) and OOA (6 µg m -3 ). The backward trajectory clustering analysis indicated the air mass from the southeast (at a frequency more than 30%) contained the higher NR-PM 1 concentration (more than 80 µg m -3 ) corresponding to the higher sulfate, nitrate and ammonium contributions.

Spatial and temporal variations of air quality and six air pollutants in China during 2015–2017

“…13 . The maximums of both the annual mean PM2.5 and PM10 concentrations were found in Xinjiang Province, and were determined to primarily be the result of mineral dust from the Taklimakan Desert 20–22 . Interestingly, the increased annual mean PM2.5/PM10 concentrations were mainly in Anhui, Shanxi, Jiangxi, and Guangdong Provinces, consistent with the variations of AQI.…”

Aircraft Measurements of the Aerosol Spatial Distribution and Relation with Clouds over Eastern China

“…Aerosols in the boundary layer have been studied extensively during the past decades (e.g., Cao et al, 2003;Hansen et al, 2003;Koulouri et al, 2008;Alam et al, 2012;Xin et al, 2015;Khamkaew et al, 2016;Xu et al, 2017), but their properties in the free atmosphere are still poorly understood; in particular, large uncertainties exist regarding the vertical distribution of aerosols in the lower troposphere (Li et al, 2015b). Aerosols appearing at the cloud level can affect cloud properties and precipitation directly, and the complex roles of aerosol vertical distributions in the climate system indicate that additional observations are required to verify climate simulations (Schwartz et al, 2014;Vuolo et al, 2014).…”

Assessing the air quality of megacities during the COVID-19 pandemic lockdown: a case study from Makkah City, Saudi Arabia

“…6b , the PM 10 concentrations were flat throughout the daytime during the pandemic lockdown period (March 11 to August 31, 2020) and the peaks are not well marked that can be interpreted by commitment of Makkah residents to the precautionary measures of COVID-19. It is worth noting that hourly patterns of PM 10 are commonly used as a notable marker of combustion emissions from road traffic and traffic-related emissions and meteorological conditions (Geng et al 2015 ; Xu et al 2016 ; Faridi et al 2018 ; Taghvaee et al 2018a , b ; Squizzato et al 2018 ; Alizadeh-Choobari et al 2016 ; Ahmed et al 2015 ; Hu et al 2014 ).

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