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)

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ＮＯｘ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ＮＯｘ的控制，但Ｏ３与ＮＯｘ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ＮＯｘ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ＮＯｘ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ＮＯｘ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ＮＯｘ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著影?

ccording to measurement result at Linan,we can address some conclusions. The O3 and its precursor NOx concentrations are higher in autumn and spring in middle latitude of China.Such higher O3 has an adverse effect on crops and economics system.O3 concentration in boundary layer is determined by photochemical process controlled by surface global radiation.There is an obviously nonlinear relationship between O3 and NOx.The data taken from period of PEMWESTA and B 1995 shows that:The production efficiency of O3 decrease with NOx concentration increasing.Althouht the efficiency of O3 production in autumn is higher than that in winter,because of the higher NOx in autumn limited (HO2) production,so the accumulated O3 concentration 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 O3 photochemical 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 O3 concentration,we should contrlo NOx discharge.)The average SO2 concentration at Kangting in Taiwan is 0.29 ppb during PEMWESTB.The SO2 concentration at Linan is 50 times higher than that at Kangting during PEMWESTB in 1994.This value may be the representive of background SO2 at island in low latitude.It is clearly that the human action effects obviously on the value of atmospheric background.