Fig. 5. Assessment of ice-nucleating particle surface area variability postulation for immersion freezing experiments.

Evaluation of the assumption of identical or variable INP surface area (ISA) per droplet for all isothermal (a) and constant cooling rate (b) immersion freezing experiments as a function of time, t, or temperature, T, respectively, given in Supplementary Table S1 for illite in water droplets. Blue color represents ISO1 and CCR1, green color represents ISO2 and CCR2, and red color represents ISO3 and CCR3. Symbols, lines, and shading are the same as in Fig. 4c. $J_{\text{het}}^{\text{apparent}}$ derived from the model in a and b was calculated from the modeled UnF in Fig. 2a and the FF in Fig. 2b with lognormally distributed ISA, however, using an incorrect assumption that droplets had identical ISA.