Approximation formulas for the microphysical properties of saline droplets

Estimating Teq, τT, and τr requires only one-step calculations; finding req is done recursively using Newton's method. The approximations for Teq and τT are quite good when compared to similar quantities derived from a full microphysical model; Teq is accurate to within 0.02 °C, and τT is typically accurate to within 5%. The estimate for equilibrium radius req is also usually within 5% of the radius simulated with the full microphysical model. Finally, the estimate of radius e-folding time τr is accurate to within about 10% for typical oceanic conditions.