The Vertical Transport of the Ozone and Carbon Monoxide by Severe Convective Weather

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.