利用1979~2013年卫星对流层臭氧遥感数据序列, 分析华北地区对流层臭氧的长期变化趋势, 考察各主要影响因子和对流层顶高度变化对臭氧变化的影响作用. 过去30多年来, 华北地区对流层臭氧长期变化趋势在不同季节差异很大: 夏季对流层臭氧呈现快速增长趋势, 增长率为1.28 DU/10 a; 冬季表现出下降趋势, 下降率为1.46 DU/10 a; 在春季和秋季表现出波动性下降趋势. 对流层臭氧夏季含量最高, 一般在50 DU上下, 春季平均值大约40 DU, 秋季平均值35 DU左右, 冬季含量最小一般在26 DU左右. 对华北地区对流层臭氧分布变化产生显著影响的因子主要有太阳周期(Solar), 厄尔尼诺-南方涛动(ENSO)和准两年振荡(QBO). 其中, Solar的影响幅度可达到5~6 DU, ENSO影响作用1~2 DU, QBO影响一般小于1 DU. 对流层顶高度在年内不同季节存在显著周期变化, 与对流层臭氧变化紧密相关, 相关系数R=0.826, 表明对流层顶高度年周期变化对对流层臭氧产生重要影响. 从年代际时间尺度上, 对流层顶高度不存在显著性变化趋势, 对对流层臭氧变化趋势影响不大.
英文摘要:
The tropospheric ozone is an important pollutant composition and greenhouse gas, of which the generation process is often closely related to the photochemical reaction of pollutant gases discharged by human activities, thereby leading to great influences on global climate change, human health, plant and crop growth, and so on. In this paper, long-time series of tropospheric ozone datasets for the period of 1979-2013 are used to investigate the long-term trends of the tropospheric ozone in northern China, and quantitatively assess the influences of major impact factors on ozone changes, while combining the effects analysis of tropopause height change on the column of the tropospheric ozone during the same period. From the decadal scale, it can be seen that the tropospheric ozone long-term trends in northern China over 30 years showed significant differences in the different seasons. Among them, the summer tropospheric ozone presented a growth trend with the growth rate of 1.28 DU/10 a, while the winter data showed a downward trend with the decline rate of 1.46 DU/10 a, and spring and autumn showed volatility characteristics and downward trend in their fluctuations. From the distribution of the different months of the year, it can be seen that the maximum occurred in the summer, commonly at 50 DU, followed by the mean of the spring at around 40 DU, then the mean of the autumn at about 35 DU. The winter minimum mean is around 26 DU. In northern China the major impact factors of tropospheric ozone include solar, ENSO and QBO. The influence of the solar cycle from trough to peak can generally reach 5-6 DU, the effect of precipitation is 5-6 DU, and the effect of ENSO is 1-2 DU, while that of QBO in most cases is less than 2 DU. The NCEP tropopause height data are used to analyze the northern China tropopause height variation, and the results show that there is no significant change in the northern China tropopause height from the decadal time scale, only a significant variation in the different seasons of the year. It is shown that the changes in tropopause height and tropospheric ozone are closely related, and the correlation coefficient R=0.826. The analysis showed that the tropopause height annual cycle changes had a significant impact on the annual cycle of the tropospheric ozone; however, the tropopause height did not exhibit significant decadal trends, thus having little effect on the tropospheric ozone changing trends at decadal time scale.