A review of ice particle shapes in cirrus formed in situ and in anvils

However, small frozen drops may experience regrowth downwind of an aged anvil in a regime with RHice > similar to 120% and then grow into rosette shapes. Identifiable particle shapes in tropical maritime anvils that have not been impacted by continental influences typically contain mostly single plate-like and columnar crystals and aggregates. Midlatitude continental anvils contain single-rimed particles, more and larger aggregates with riming, and chains of small ice particles when in a highly electrified environment.

The particles in subvisible cirrus are < similar to 100 mu m and quasi-spherical with some plates and rare trigonal shapes. Percentages of particle shapes and power laws relating mean particle area and mass to dimension are provided to improve parameterization of remote retrievals and numerical simulations.