ENVIRSC 1A03 Lecture Notes - Lecture 9: Supercooling, Viscous Liquid, Vapor Pressure
26 Apr 2015
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At this point, the drop falls at a constant speed known as terminal velocity. Large drops fall quicker due to smaller ratio of surfaces area to weight. If a cloud has small droplets of uniform size, the droplets are less likely to collide with each other. They all fall slowly at the same speed: the drops that do collide frequently do not coalesce. In clouds with differently sized drops, the larger ones fall faster than small ones. Must be greater than 0. 2 mm in diameter in order to fall. True raindrops are bigger than 0. 5 mm in diameter. Sleet- is rain at some point while hitting the ground. occurs when a partially melted snowflake or cold raindrop freezes, forming an ice pellet before reaching the ground. Freezing rain hits the ground as supercooled water, freezing upon contact, creating a glaze. Ice crystals are held aloft by strong up drafts.
