黑龙江省龙凤山区域大气本底站气溶胶光学特征分析

Analysis of aerosol optical characteristics of Longfengshan regional background station in Heilongjiang province

利用2010—2020年黑龙江省龙凤山区域大气本底站气溶胶光学特性长期观测资料,分析并探讨了背景地区气溶胶光学厚度、波长指数、单次散射反照率、粒子体积谱分布以及气溶胶直接辐射强迫效应的变化特征。结果表明:龙凤山区域气溶胶光学厚度最高值出现在7月,平均值为0.67;最小值出现在12月、1月和2月,平均值分别为0.17、0.02和0.18;气溶胶光学厚度在17时达到最高值为0.39。气溶胶波长指数在4—5月最低,平均值分别为1.20和1.21;12月最高,平均值为1.74;波长指数在12时达到峰值,为1.44。单次散射反照率最低值分别出现在4月、8月和10月,平均值分别为0.84、0.82和0.84;气溶胶单次散射反照率在12时出现峰值,为0.95。龙凤山区域春季气溶胶粗粒子体积分数最高值出现在5月,为0.04μm^(3)·μm^(-2),有效半径为3.85μm;夏季气溶胶细粒子体积分数最高值出现在7月,为0.06μm^(3)·μm^(-2),有效半径为0.19μm;秋冬季龙凤山背景地区气溶胶细粒子和粗粒子体积分数均进一步减小。龙凤山区域地面和大气层顶气溶胶直接辐射强迫最高值均出现在7月,分别为-94.44 W·m^(-2)和-22.33 W·m^(-2)。

Based on the long-term observation data of aerosol optical properties at Longfengshan regional background station in Heilongjiang province from 2010 to 2020,the variation of aerosol optical depth,Angström exponent,single scattering albedo,particle volume size distribution,and aerosol direct radiative effect were analyzed.The results show that the maximum aerosol optical depth in the background area appears in July,with an average value of 0.67.The smaller values occur in December,January,and February,with an average value of 0.17,0.02,and 0.18,respectively.The daily aerosol optical depth reaches the highest value of 0.39 at 17:00.The Angström exponent decreases significantly in April and May,with an average value of 1.20 and 1.21,respectively.The Angström exponent reaches the largest value in December,with an average value of 1.74.The low value of single scattering albedo(SSA)occurs in April,August,and October,with the average values of 0.84,0.82,and 0.84,respectively.The peak Angström exponent reaches 1.44 at noon.The maximum volume of coarse mode particles appears in May,which is about 0.04μm^(3)·μm^(-2),and the effective radius is about 3.85μm.The maximum volume of fine mode particles is 0.06μm^(3)·μm^(-2) with an effective radius of 0.19μm appeared in July.In autumn and winter,the volume of fine and coarse mode particles further decreases in Longfengshan.The maximum values of aerosol direct radiative effect at the ground and on the top of the atmosphere appear in July with values of-94.44 W·m^(-2) and-22.33 W·m^(-2),respectively.