scholarly journals Urban Boundary Layer Height Characteristics and Relationship with Particulate Matter Mass Concentrations in Xi’an, Central China

2013 ◽  
Vol 13 (5) ◽  
pp. 1598-1607 ◽  
Author(s):  
Chuanli Du ◽  
Shuyan Liu ◽  
Xing Yu ◽  
Xingmin Li ◽  
Chuang Chen ◽  
...  
2018 ◽  
Vol 47 (7) ◽  
pp. 717007
Author(s):  
谭 敏 Tan Min ◽  
谢晨波 Xie Chenbo ◽  
王邦新 Wang Bangxin ◽  
吴德成 Wu Decheng ◽  
马 晖 Ma Hui ◽  
...  

2015 ◽  
Vol 15 (12) ◽  
pp. 16775-16859
Author(s):  
S. M. Sakerin ◽  
A. A. Bobrikov ◽  
O. A. Bukin ◽  
L. P. Golobokova ◽  
Vas. V. Pol'kin ◽  
...  

Abstract. We presented the results of expedition measurements of the set of physical-chemical characteristics of atmospheric aerosol in water basins of Arctic and Far East seas, performed onboard RV Akademik Fedorov (17 August–22 September 2013) and RV Professor Khljustin (24 July–7 September 2013). The specific features of spatial distribution and time variations of aerosol optical depth (AOD) of the atmosphere in the wavelength range of 0.34–2.14 μm and boundary layer height, aerosol and black carbon mass concentrations, and disperse and chemical composition of aerosol are discussed. Over the Arctic Ocean (on the route of RV Akademik Fedorov) there is a decrease in aerosol and black carbon concentrations in northeastern direction: higher values were observed in the region of Spitsbergen and near the Kola Peninsula; and minimum values were observed at northern margins of the Laptev Sea. Average AOD (0.5 μm) values in this remote region were 0.03; the aerosol and black carbon mass concentrations were 875 and 22 ng m-3, respectively. The spatial distributions of most aerosol characteristics over Far East seas show their latitudinal decrease in the northern direction. On transit of RV Professor Khljustin from Japan to Chukchi Sea, the aerosol number concentration decreased, on the average, from 23.7 to 2.5 cm-3, the black carbon mass concentration decreased from 150 to 50 ng m-3, and AOD decreased from 0.19 to 0.03. We analyzed the variations in the boundary layer height, measured by ship-based lidar: the average value was 520 m, and the maximal value was 1200 m. In latitudinal distribution of the boundary layer height, there is a characteristic minimum at latitude of ∼ 55° N. For water basins of eight seas, we present the chemical compositions of water-soluble aerosol fraction (ions, elements) and small gaseous impurities, as well as estimates of their vertical fluxes. It is shown that substances are mainly (75–89 %) supplied from the atmosphere to the sea surface together with small gaseous impurities. The deposited ions account for from 11 to 24.5 %, and trace elements account for 0.2–0.4 %. The average vertical fluxes of aerosol substance are a factor of 4–7 larger in the Japan Sea than in the water basins of Arctic seas.


1999 ◽  
Vol 38 (6) ◽  
pp. 945 ◽  
Author(s):  
Laurent Menut ◽  
Cyrille Flamant ◽  
Jacques Pelon ◽  
Pierre H. Flamant

2017 ◽  
Author(s):  
Ting Yang ◽  
Zifa Wang ◽  
Wei Zhang ◽  
Alex Gbaguidi ◽  
Nubuo Sugimoto ◽  
...  

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.


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