The impact of gravity waves on the evolution of tropical anvil cirrus microphysical properties

The Kelvin effect (higher saturation vapor pressure over curved surfaces) is a critical factor in the anvil evolution, driving mass transfer from small to large ice crystals. The wave-driven decrease in ice concentration is much faster for typical anvil cirrus detrained at similar or equal to 11.5-12.5 km than for less frequent anvils at 15.5-17.5 km because of the strong temperature dependence of deposition growth and sublimation rates.

The simulations also show that waves, along with the Kelvin effect, drive growth of mid-sized (5-20 mu m) ice crystals, which is consistent with the observed transition to bullet rosette habits in aging anvil cirrus. We conclude that high-frequency gravity waves, which are generally not resolved in large-scale models, likely have important impacts on anvil cirrus microphysical properties and lifetimes.