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PRECIPITATION. CURVATURE EFFECT. Q. Why are cloud droplets larger over the ocean?. COLLISION- COALESCENCE PROCESS. Most collide on forward edge Some collide on backside. Terminal velocity : Almost 10 m/s for largest raindrops. Q. Why can a cumuliform cloud produce
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Q. Why are cloud droplets larger over the ocean?
COLLISION- COALESCENCE PROCESS Most collide on forward edge Some collide on backside Terminal velocity: Almost 10 m/s for largest raindrops
Q. Why can a cumuliform cloud produce heavier precipitation than a stratiform cloud? "Warm" Cloud
Supercooled water droplets "Cold" Cloud
Deposition nuclei Ice forms directly on ice nuclei Freezing Nuclei Promote freezing of supercooled droplets (contact nuclei)
Ice crystals grow at the expense of water droplets Higher saturation vapour pressure
Riming causes • snow pellets (graupel) • supercooled droplets • freeze on contact Snowflakes form through aggregation
ARTIFICIAL CLOUD SEEDING Source: Desert Research Institute, Nevada, USA Source: North Dakota Cloud Modification Project, USA
18cm diameter World's Largest Hailstone Aurora, Nebraska June 22, 2003
I almost didn't make it here !
AIR PRESSURE, FORCES AND WIND