If water is included, relative humidity was set to a lower limit of 34% and a higher limit of 73% based on the relative humidities used by He et al. The concentrations of IsA, IT, and IP was set as a fraction of the IA concentration. IT and IP was set to 1% of IA based on the relative concentration of IT reported by He et al., while the IP concentration was assumed to be identical to IT due to a lack of measurements. The relative concentration of IsA varied with temperature, with a relative concentration of 1% of IA at 283 K, and 3% of IA at 263 K based on the data reported by Zhang et al. The ranges for SA and IA is based on reported concentrations in the Arctic and in marine areas. FA, MSA, and NA concentrations were chosen to be consistent with previous studies. 3 Results and Discussion