Temperature dependence of heterogeneous uptake of N₂O₅ by ammonium sulfate aerosol

We present laboratory measurements of the dependence of the uptake coefficient γ on temperature for removal of the NO x reservoir N 2 O 5 by sub‐micron aerosols containing ammonium sulfate and ammonium hydrogen sulfate. Uptake coefficients were measured over the range 263–303 K at 50% RH, which varied in the range 0.005–0.036. A simple negative dependence of uptake on temperature is observed for ammonium sulfate over this range, while the form of the temperature dependence of uptake by ammonium hydrogen sulfate is more complex. The results consolidate those of an earlier less definitive study of the temperature effect on N 2 O 5 uptake.