Atmospheric pollutant deposition over a south central north carolina cornfield

摘要

The National Oceanic and Atmospheric Administration Atmospheric Turbulence and Diffusion Division (ATDD) model was used to infer the dry deposition velocities of gaseous and particle pollutants, such as O_3, SO_2, NO_2, and sufate and nitrate aerosols onto a cornfield in North Carolina (35.7 deg N, 76.8 deg W) during its growing season. The average windspeed, standard deviation of the wind direction and the average air temperature were 2 (+-) m s~(-1), 18 deg (+- 28 deg ), and 29 (+-) deg C at 10 m AGL, respectively. The deposition velocity of ozone is in the range of 0 to 2.9 cm s~(-1) which an average of 0.7 (+-0.5) cm s~(-1) with an average of 0.15 (+-0.07) cm s~(-1). The average ozone and SO_2 concentrations were 48 ppb and 8 ppb, respectively, suggesting that the ozone and sulfur dioxide depositions are 0.06 (+-0.06) and 0.003 (+-0.002) kg ha~(-1) h~(-1), respectively. Mass flux density of nitrogen oxides is 2 g N ha ~(-1) h~(-1), and the mass flux density of nitrogen dioxide was estimated to lie between -2 and -6 g ha~(-1) h~(-1), where minus indicates a downward flux. The ozone deposition velocities compare well with available data.