临安冬夏季SO2、NO2和O3体积分数特征及与气象条件的关系

对临安大气本底站2003-2004年冬、夏季二氧化氮(NO2)、二氧化硫(SO2)、臭氧(O3)进行了分析.结果表明:冬季NO2和SO2平均体积分数分别为19.48×10-9和35.74 x10-9,而夏季的平均体积分数分别为4.81×10-9和8.12×10-9,冬季高于夏季；O3在夏季的平均体积分数为33.55×10-9,略高于冬季的25.44×10-9；夜间NO2和SO2体积分数比白天高,并且NO2呈明显的单峰单谷型分布,O3也呈单峰型但峰值出现在白天.NO2、SO2体积分数存在着明显的“假日效应”,假日比非假日低,周五高于假日和非假日；但O3体积分数没有明显的假日效应.降水对SO2有明显的清除作用,但对NO2的清除作用不明显.与风向对比发现,夏季高体积分数的NO2、SO2都受到NW、WNW风的影响,冬季则分别受NE和SW、SSW风的影响；而O3受风向的影响较复杂,与局地光化学反应有关.

Characteristics of SO2, NO2, O3 volume fractions and their relationship with weather conditions at Linan in summer and winter

This paper studies NO₂,SO₂,and O₃ at Linan in summer and winter of 2003 and 2004.Results show that the mean volume fractions of NO₂ and SO₂ are 19.48×10^-9 and 35.74×10^-9 in winter,respectively,which are higher than those in summer(4.81×10^-9 and 8.12×10^-9, respectively).The mean volume fractions of O₃ is 33.55×10^-9 in summer,which is higher than that in winter (25.44×10^-9).The volume fractions of NO₂ and SO₂ during the daytime are lower than those during the nighttime.The diurnal variation of NO₂volume fraction shows the single valley and single peak distribution with its peak during the nighttime.The diurnal variation of O₃ volume fraction is similar to NO₂,but its peak appears during the daytime.The volume fractions of NO₂ and SO₂ show an obvious "Holiday Effect",and are obviously lower during weekends than those during weekdays,with the highest on Fridays.The volume fraction of O₃ does not have an obvious "Holiday Effect".The wet removal efficiency of precipitation to SO₂ is more obvious than to NO₂.By contrast with the different wind directions,the higher volume fractions of NO₂ and SO₂ are affected by NW and WNW winds in summer,while by NE,SW and SSW winds in winter.The influence of wind direction on the ozone is complex,which is relevant to local photochemical reactions.