中美大气化学联合考察实验结果的初步分析与比较

PRELIMINARY ANALYSIS AND COMPARISON OF RESULT IN FIELD EXPERIMENT OF SINO-US ATNOSPHERIC CHENICAL COOPERATION INVESTIGATION (PEN-WEST-B)

中文关键词:  大气臭氧  本底  前体物

英文关键词:Atmospheric O₃  Backg round  Precursor

中文摘要:

      根据临安区域本底站观测资料分析结果得出,中国中纬度地区秋、冬季O₃及其前体物NO_x等浓度偏高,可以对农作物和地表生态系统产生影响.观测结果表明:近地层大气O₃浓度主要决定于地面总辐射量控制下的光化学反应过程;O₃的生成受到前体物NO_x的控制,但O₃与NO_x存在着明显的非线性关系.从PEM-WESTA和B的实验及1995年的观测资料表明,O₃的生成效率随着NO_x浓度的增大而减小.尽管O₃的生成速率秋季比冬季的大,但由于秋季较高的NO_x抑制了过氧基的生成,因此冬季O₃的累积量几乎可以和秋季相比拟.在临安观测的NMHC和NO_x的比值比国外同纬度地区测值要大.这说明在临安本底站O₃的光化学生成中,NMHC不是控制物种.从而提示我们,在这些季节临安O₃光化学产物能够被NO_x浓度所控制.中美大气化学联合考察(PEM-WEST-B)实验期间,台湾省的卡盯站SO₂的平均浓度为0.29ppb,O₃的平均浓度为42.2ppb,可以认为此值为低纬度海岛的本底值.1994年PEM-WEST-B实验期间临安站的观测资料和台湾省的卡盯站资料相比,临安站SO₂的浓度约为卡盯站SO₂浓度的50倍左右,从而可以看出人类活动对大气本底的显着影响.

英文摘要:

      A ccording to measurement result at Linan,we can address some conclusions.The O₃ and its precursor NO_x concent rations are higher in autumn and spring in middle latitude of China.Such higher O₃ has an adverse effect on crops and economics system.O₃ concent ration in boundary layer is determined by photochemical process controlled by surface global radiation.There is an obviously non-linear relationship between O₃ and NO_x.The data taken from period of PEM-WEST-A and B 1995 shows that:The production efficiency of O₃ decrease with NO_x concentration increasing.Althouht the efficiency of O₃ production in autumn is higher than that in winter,because of the higher NO_x in autumn limited (HO₂) production,so the accumulated O₃ concent ration in winter almost is comparable with that of in autumn.The ratio of NMHC to NO_x at Linan is higher than that at abroad similar latitude.It seems that O₃ photo chemical production may be comtroled by NO_x at Linan in these seasons.(There for it prompts that because of the NMHC produced by nature resources is higher,so if we want to control O₃ concentration,we should contrlo NO_x discharge).The average SO₂ concentration at Kangting in Taiwan is 0.29 ppb during PEM-WEST-B.The SO₂ concent ration at Linan is 50 times higher than that at Kang ting during PEM-WEST-Bin 1994.This value maybe the representive of background SO₂ at island in low latitude.It is clearly that the humanaction effect so bviously on the value of at mospheric background.