Extended Data Fig. 7: Saturation ratio as a function of temperature.
From: Rapid growth of new atmospheric particles by nitric acid and ammonia condensation
At constant nitric acid and ammonia, a decline in temperature leads to an exponential increase in the saturation ratio of ammonium nitrate, shown as the product of nitric acid and ammonia vapour concentration. With an adiabatic lapse rate of −9 °C km−1 during adiabatic vertical mixing, upward transport of a few hundred metres alone is enough for a saturated nitric acid and ammonia air parcel to reach the saturation ratio capable of triggering rapid growth at a few nanometres.
