storm clouds. cumulonimbus clouds cold rain process
Post on 15-Jan-2016
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Storm clouds
Cumulonimbus clouds
Cold rain process
Saturated vapour pressure
Ice crystals grow at the expense of supercooled water droplets.
Air is saturated over ice.
Air is not saturated over water.
Water evaporates from the supercooled droplets - the droplets disappear
The water vapour deposits on the ice crystals - the crystals grow
Falling ice particles
Development of cumulonimbus
Multi-cell storm
Thunder and Lightening
Lightening
Forked lightening from cloud, showing stepped leaders and main return stroke
Lightening originating from a tower on the ground, note forks go upwards.
Time resolved lightening formation
Supercell thunderstorm
Contrails
At high altitude ~10 km temperature very low, condensation aided by exhaust particulates and vortices.
Nacrecous clouds
Nacrecous clouds are 15 - 25 km high, in the stratosphere well above tropospheric clouds, and occur mostly in polar regions and in winter at high latitudes. Seen after dusk.Also called mother-of-pearl or polar stratospheric clouds.
Noctilucent clouds
Noctilucent clouds are thought to be composed of small ice-coated particles; their precise nature remains a mystery. They form at very high altitudes ~ 82 km - and are a quite separate phenomenon from normal tropospheric clouds.