北半球地面臭氧的分布和变化特征分析

【作者】 张倩；

【导师】 任??；

【作者基本信息】 中国科学技术大学 ， 大气物理， 2006， 硕士

【摘要】 地面臭氧的含量变化对于地球上的生态环境和气候都有影响。囿于地面臭氧观测资料的限制，以往大多数研究都是针对局地地面臭氧含量较短期的变化特征的分析，而对于洲际各区域之间，洋面和内陆、海岸的地面O3分布特征，各区域地面O₃季节、日变化以及长期变化趋势认识有限。本文利用来自GAW（全球大气监测）的由WDCGG（世界温室气体数据中心）收集整理和发布的、基于地基观测的北半球共15个站点的地面O₃含量的逐月观测资料以及逐时观测资料，分析对比并总结了北半球不同经纬度各区域的地面O₃含量的年变化和各个季节的日变化规律。研究表明： 一、内陆比较清洁地区的地面O₃多年月平均变化曲线为单峰型，接近正弦曲线的形状，最高值出现在四月份，最低值出现在十月份；而空气污染比较严重的地区可能会发生峰值出现推迟一个月的情况，甚至出现连续多个月份浓度均较高的情况。而位于20°N～35°N的洋面以及海岸线上的站点均在夏季出现全年最低值。 二、对于四个季节的平均日变化而言，清洁地区的日变化很小，曲线比较平直，而污染比较严重的区域则日变化明显，曲线弯曲幅度大，其中夏天的日变化差别最明显。 三、用小波分析的方法分析各站点地面O₃含量的变化周期，各站点地面O₃分别表现出的明显的周期除年变化以外，有准两年、四年和11年这三个周期。随着站点位置的不同，有的只表现出这三个周期中的一个或者两个，有的这三个周期均很明显，且各站点在相同准周期中表现出的周期也随位置不同而略有差异。 四、处于副高控制区域的站点的多年平均与其它区域的各站点相比，地表O₃的月变化有很显著的不同。分析这几个站点的地面O₃与500hpa位势高度场的关系发现在这些站点距其很近的东北方，500hpa位势高度距平场和地面臭氧的含量之间均存在一个负相关的高值区域。 五、进一步分析了副高控制区与各站点地面臭氧含量的和可降水含量之间的关系。发现地面臭氧含量和其东北边临近地区的可降水含量之间有负相关的关更多还原

【Abstract】 Content of surface ozone influences the environment and meteorology on the earth. Restricted by the observation data of surface ozone content, most studies were about short-term variation characteristics of a certain local place, while little was know about long-term variation characteristics in continental scale. In the thesis, surface ozone data of Mauna Loa and other 14 monitoring sites of altitude lower than 1000m in the northern hemisphere were used to give a joint discussion for the distribution and variation features of surface O3. The data, based on ground observation, were collected, processed, and distributed by WDCGG(The World Data Centre for Greenhouse Gases) in GAW(Global Atmosphere Watch). he monthly mean and hourly data of surface ozone in these 15 sites were analysed to sum up the difference of surface ozone annual and seasonal variations in different districts of the northern hemisphere. The results showed that:Firstly, the monthly mean of surface O3 was like a sinusoid curve with one peak in April and one trough in October in the districts with relatively clean air in land while the peak might be delayed to one month later or the content might be high in several months in the late spring and summer in the districts where the air was relatively heavily polluted,. And the minimum of surface ozone appeared in summer for the sites of latitude between 20° N—35° N in the oceans and along the coasts.Secondly, as to the mean diurnal cycle of the four seasons of 1995, the clean area did not show strong diurnal variability of surface ozone with a relatively straight line, while in the polluted area the diurnal variability are obvious especially in summer with the maximum in about 3 p.m. and the minimum before sunrise.Thirdly, CWT(Continue Wavelet Transform) were used to analyze the period of surface O3 of the sites, and contents of surface ozone of the sites showed quasi-biennial , quasi-four year and quasi-eleven year periods besides the obvious annual variation. Not the surface ozone content of every sites showed these three periods, some showing one or two out of these 3 periods and some showing them all. It differed with the location of the sites.更多还原