摘要
2002年夏季,以北京325m气象塔为观测平台,进行了大气污染物臭氧(O3)及其前体物氮氧化物(NOx)和气象要素加强期的同步观测,并对观测资料做了详尽分析。结果表明:边界层内存在明显的臭氧浓度垂直差异;低层(120m)O3浓度呈明显的日变化,且昼夜振幅较大;夜间高层(280m)O3的化学消耗较弱,可维持较高的浓度;稳定度(Ri)在低层以中性态居多,振幅较小,而在高层以不稳定态居多,振幅较大。两层O3湍流输送通量都呈单峰变化。白天,在O3前体物和局地光化学反应共同作用下,120m左右处的O3污染最大。
O_3,NOx concentrations and meteorological parameters in the urban atmospheric boundary layer in July 2002 were synchronously measured on a meteorological tower of 325m in Beijing.Analysis results show that the O_3 concentration differs remarkably at different levels,showing a distinct diurnal variation at the low level (120m) and maintaining a higher value at night at the higher level (280m) due to a weaker chemical depletion of O_3.In daytime the ozone pollution is most severe at 120m due to the joint effect of O_3 progemtor and local photochemistry reaction.The stability (Ri) is mostly neutral and the variations of Ri are small at lower levels;and it is frequently unstable,and its variation is large at higher levels.The O_3 fluxes transferred by turbulence show a single-peak change both in the lower and higher levels.
出处
《南京气象学院学报》
CSCD
北大核心
2004年第3期413-419,共7页
Journal of Nanjing Institute of Meteorology
基金
中科院知识创新工程重大项目(KZCX1-SW-01-01B)
国家自然科学基金资助项目(40205003)
关键词
通量
臭氧
稳定度
大气边界层
flux
ozone
stability
atmospheric boundary layer
