Reactive uptake coefficients for heterogeneous reaction of N2O5 with submicron aerosols of NaCl and natural sea salt

[摘要] The kinetics of uptake of gaseous N₂O₅ on submicron aerosols containing NaCl and natural seasalt have been investigated in a flow reactor as a function of relative humidity (RH) in the range30-80% at 295±2K and a total pressure of 1bar.The measured uptake coefficients, γ, werelarger on the aerosols containing sea salt compared to those of pure NaCl, and in both casesincreased with increasing RH.These observations are explained in terms of the variation in thesize of the salt droplets, which leads to a limitation in the uptake rate into small particles.Aftercorrection for this effect the uptake coefficients are independent of relative humidity, and agreewith those measured previously on larger droplets.A value of γ=0.025 is recommended for thereactive uptake coefficient for N₂O₅ on deliquesced sea salt droplets at 298K and RH>40%.

[学科分类] 大气科学