Spatial Distribution Properties Of Atmospheric Particles Over Central Beijing-Tianjin-Hebei Region In Summer Of 2016

Taking the Yun12?Y12?plane as the observation platform of atmospheric particulate matter,aircraft measurements of aerosol properties in central Beijing-Tianjin-Hebei Region were carried out in the summer of 2016.It was found that Tianjin city proper and Gaocun town atmospheric particle number concentration spectrum characteristics of vertical distribution are monotonically decreasing and unimodal distribution,the maximum value of the peak was between 0.3⁰.4 m,the concentration spectrum under 1500 m?The heights in the following were all standard pressure height.?was unimodal distribution which ranged from 0.35 to 0.4?m,while the concentration spectrum of above1500 m was monotonically decreasing.The maximum value of the peak was about 900 m.The volume concentration spectrum under 2200 m was trimodal distribution,which ranged from 0.3 to 0.4?m,0.5 to 0.6?m,1 to 2?m respectively.The maximum value of the peak occered at around 450 m.The concentration spectrum of 600m and 2400m atmospheric particles in Tianjin,Baoding and Hengshui were single-peak distribution and monotonically decreasing.The concentration spectrum of 600 m surface area was trimodal distribution in Tianjin,Baoding and Hengshui,which ranged from 0.3 to 0.4?m,0.5 to 0.6?m,1 to 2?m respectively.The surface area concentration spectrum of 2400 m in Tianjin,Baoding and Hengshui was bimodal distribution,one of which ranged from 0.3 to 0.4?m,and the other ranges from 0.5 to 0.6?m.The volume concentration spectrum of 600 m and 2400 m in Tianjin,Baoding and Hengshui were trimodal distribution,which ranged from 0.3 to 0.4?m,0.5 to0.6?m,1 to 3?m respectively.The vertical distribution characteristics of Tianjin were in the single peak distribution of the concentration spectrum under1500 m which appeared in the accumulation mode,and the concentration spectrum above 1500 m was monotonically decreasing.The maximum value of the peak was about 900 m.It was found that the inversion layer had an important influence on the formation of aerosol accumulation.The volume concentration spectrum under 2200 m was trimodal distribution.The maximum value of the peak was around 450 m.The distribution characteristics of concentration spectrum distribution over Beijing-Tianjin-Hebei Region were the same as those of the atmospheric airborne particles of 600 m and 2400 m,showing a monotonously decreasing and unimodal distribution.The differences in the peak of concentration spectrum between different cities were affected by the ground mass concentration of particles.The surface area concentration spectrum of 600 m and 2400 m in central Beijing-Tianjin-Hebei Region were trimodal distributions and bimodal distribution respectively,owning to it was dominated by fine particles in the air of 2400 m.The volume concentration spectrum of 600 m and 2400 m in central Beijing-Tianjin-Hebei Region were trimodal distributions,nevertheless,studies from foreign countries observed bimodal distribution.It was found that there were much differences between crest value of size range of coarse particles,due to higher value of PM_2.5/PM₁₀ratio in our country.The atmospheric particles of 600 m and 1200 m in central Beijing-Tianjin-Hebei Region were mostly transported from Shandong and Henan provinces near the ground.The atmospheric particles of 2400 m in central Beijing-Tianjin-Hebei Region were mostly transported from Inner Mongolia area by two ways of high aititude and near the ground.The atmospheric particulates of 500 m and 1000 m in Tianjin city proper and Gaocun town were mostly transported from the Pacific,Bohai,the Yellow Sea and Shandong provinces near the ground.The atmospheric particulates of 2000m in Tianjin city proper and Gaocun town were mostly came from Shandong provinces.