利用ACTIVE(aerosol and chemical transport in tropical convection)试验资料,取2006年1月20日澳大利亚北部达尔文岛附近发生的一次飑线强对流天气的AE17航次和2006年1月27日无对流天气的AE21航次飞行路径中的探测资料,对澳大利亚达尔文地区夏季风盛行期间发生的有无强对流发生时O_3和CO浓度垂直分布变化进行对比,考察强对流性天气发生对O_3和CO浓度垂直输送作用。深对流云内强烈的垂直上升运动将O_3和CO等化学气体携带输送至对流层上部并在对流层顶堆积,从而在对流层上部产生浓度峰值。当有强对流发生,飞机进入对流云上层时,O_3浓度和CO浓度升高,O_3和CO浓度变率增大,在对流层上部浓度出现峰值;当飞机飞出对流云时,O_3和CO浓度相对较低,在对流云外出现谷值。在无对流发生的条件下O_3和CO浓度相对较小,浓度变率也较小,无峰值产生。分析表明:O_3和CO浓度分布不仅与强对流的垂直输送作用关系密切,且与气象要素垂直和水平分布以及动力输送过程密切相关。
英文摘要:
Clouds have significant impacts on the quality of the atmosphere in the troposphere, the redistribution of chemical gases and climate change. In general, environmental and climatic effects of atmospheric pollutants are to a large extent determined by their vertical distribution in the atmosphere. Deep convective clouds,as the main carrier of vertical conveying of atmospheric mass,can transport air from the boundary layer to the upper troposphere in a very short time. So various chemical gaseous components can be transported from lower layers to the upper troposphere or even the lower stratosphere in a relative short time and this process can also increase the chemical gas residence time in the atmosphere. Using ozone and carbon monoxide data obtained from aircraft observations for altitude from 1 to 15 km near Darwin(12.41°S, 130.9°E) in northern Australia, in the Aerosol and Chemical Transport in Tropical Convection (ACTIVE) campaign from November 2005 to February 2006,a squall line process on 20 January 2006 and a non-convective weather day on 27 January 2006 are compared. Differences between the distribution of ozone and carbon monoxide in severe convective and non-convective conditions are analyzed. According to results of contrastive analysis, there is a very close relationship between the peak concentration of ozone and carbon monoxide in upper troposphere and the appearance of strong convective systems. Severe vertical ascending motion inside the deep convective cloud carries ozone, carbon monoxide and other chemical gases to the top of the troposphere,and then these chemical gases accumulate in the upper troposphere, leading to a peak concentration. Results show that in convection, the concentration of cloud particles and chemical gas such as ozone, carbon monoxide rise and their variability is large too. At the same time, peak concentrations of ozone and carbon monoxide appear in the upper troposphere. But outside convective clouds, concentrations of cloud particles, ozone and carbon monoxide all drop. On the contrary, under non-convective condition, concentration of ozone is stable, and no peak value is observed. Results show that deep-convective cloud have obvious vertical conveying effects on ozone and carbon monoxide. The distribution of ozone and carbon monoxide closely rely on vertical conveying of strong convection, as well as distribution of meteorological factors and synoptic dynamic transportation process.