Measurements And Modeling The Ozone Flux On Bare Soil

At present, zone has become one of the most important atmospheric pollutants.Based on bare soil under the condition of experiment,the soil deposition is one of the main channel as ozone dry deposition,the main factors affecting the soil deposition has not been set.Based on the proven ozone deposition of the bare soil and its influencing factors.According to the mathematical models of soil resistance,and combining with the atmospheric concentration of nitric oxide,soil emission flux of nitric oxide,soil emission flux of nitric oxide on evaluated.The main results as follows:(1)December: The mean value of the ozone concentration is 41.1ppb.The mean value of the ozone dry deposition flux is -1.64nmol·m-2·s-1 (negative sign means that the deposition direction is down to the soil). The mean value of the aerodynamic resistance is 90.41 s·m-1. The mean value of quasi-laminar boundary layer resistance is 76.37s·m-1. The mean value of the soil resistance is 595.7s·m-1.June: The mean value of the ozone concentration is 21.46ppb.The mean value of the ozone dry deposition flux is -3.38nmol·m-2·s-1 (negative sign means that the deposition direction is down to the soil). The mean value of the aerodynamic resistance is 51.57s·m-1. The mean value of quasi-laminar boundary layer resistance is 66.19s·m-1. The mean value of the soil resistance is 627.42s·n-1.The flux and rate of ozone deposition, the erodynamic resistance, and the quasi-laminar boundary layer resistance and the soil resistance have diurnal fluctuation.(2)In order to know the process of the ozone depositionin bare soil and to simulate the soil resitiance,the soil resistiance model is established and revised through local parameterized.(3)Although it is assumed in previous studies that soil resistance is a function of soil water content (SWC), the results of this study indicate that SWC is not the main factor controlling Rsoil which shows daily and hourly variations.(4)The measured and parameterised ozone deposition velocities agree well when soil NO emissions are negligible. However, when there are large soil NO emissions, the parameterised ozone deposition strongly underestimates the measured deposition velocity even if the chemical destruction of ozone by reaction with NO in the air column was evaluated to be negligible. This suggests that soil NO emissions enhance soil ozone deposition by chemical reaction at or near the soil surface.