摘要
基于标准Umkehr反演算法, 利用北京地区Dobson仪器逆转观测资料, 反演计算出臭氧垂直分布.在反演过程中加入气溶胶订正因子, 使反演结果更加合理.利用臭氧垂直分布反演结果, 研究1990~2002年北京地区臭氧垂直分布特征和变化情况.结果表明在1992年秋季和1993年春季期间, 在10.3~23.5 km范围内臭氧浓度有较大幅度降低, 造成了这个期间月平均臭氧总量的明显偏低; 1990年到2002年期间, 臭氧总量的变化呈现出缓慢下降趋势, 但不同高度臭氧含量的变化趋势有所不同.
The ozone vertical profiles have been retrieved from the Dobson Urnkehr observations of Beijing [39°45′N, 117°00′E (before 5 April 1994); 39°58′N, 116°22′E (after 5 April 1994)] from 1990 to 2002 based on standard Umkehr inversion algorithm. The corrections are made for aerosols in the process of inversion, and the retrieved resuits have been improved. This paper presents monthly mean ozone profile results of October 1990 and October 1993, and the seasonal average ozone concentration versus time in Umkehr layers 2 - 8 of Beijing in the spring (March, April and May) and fall (September, October and November) of 1990 - 2002. Comparison of these results with those from the Stratospheric Aerosol and Gas Experiment Ⅱ (SAGE Ⅱ) satellite measurements has also been Carried out. The spring and fall average ozone concentration variation trends, measured by Dobson spectrophotometer and by SAGE Ⅱ satellite instrument are in good agreement. Using the derived profiles, combined with the total ozone data measured by Dobson spectrophotometer, the characteristics and variations of ozone vertical distribution of Beijing during 1990 - 2002 are studied. The results show: (i) The aerosol effects tend to produce an apparent decrease in ozone concentration above layer 5 (above 23. 5 km), and an apparent increase in ozone concentration in the lower layers. In the case of October 1990, the ozone profile error caused by aerosol [(ozone profile with aerosol correction- uncorrected ozone profile)/ uncorrected ozone profile )〈 100%] is less than 2. 6 % (the absolute value) in layers 3 - 6 (14. 7 - 32. 6 km), and less than 8. 7% in layers 7 - 9 (32. 6 - 47. 9 km). This indicates that during the quiescent years, the effect of aerosols is not obvious. But in the case of October 1993, affected by volcanic eruption of Pinatubo of 1991, the ozone profile error caused by aerosol reached 5. 9% (the absolute value) in layers 3 - 6, and reached 18% in layers 7 - 9. So it is necessary to make corrections for aerosols during the periods following strongvolcanic eruptions. (ii) In the fall of 1992 and the spring of 1993, the seasonal average ozone concentrations in layers 2 - 4, corresponding to the height of 10. 3 - 23. 5 krn, were unusually lower than normal. In the fall of 1992, the ozone concentrations in layer 4 (19. 1 - 23.5 krn, the height of the maximum) was 7. 5% lower than normal; in the spring of 1993, the ozone concentrations in layer 3 (14. 7 - 19.1 km) was 31% lower than normal. The ozone concentration reduction in the lower stratosphere caused the total ozone decrease seriously from the fall of 1992 to the spring of 1993. (iii) From 1990 to 2002, the monthly mean total ozone decreased slightly, but the trends of change of ozone concentrations at different altitudes were different: ozone concentrations in layers 2 - 4 and 7 - 8 (32. 6 - 42. 6 kin) had a trend of decrease; but ozone concentrations in layers 5 - 6 (23. 5 - 32. 6 krn) presented a trend of increase.
出处
《大气科学》
CSCD
北大核心
2005年第5期709-716,共8页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金资助项目40475014
40175009
和40333029