ERTH 2415 Lecture Notes - Lecture 18: Cumulus Cloud, Extreme Weather, Natural Disaster
3 Dec 2015
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Document Summary
Takeaways: to apply knowledge about climate and weather to the understanding of the characteristics and development of thunderstorms, tornadoes and ice storms. Low pressure: rises, holds more humidity, molecules move more. High pressure: sinks, holds less humidity, molecules move less. Thunderstorm meteorological event associated with a localized storm cloud producing thunder and lightning: thunderstorms are composed of individual cells developing over 20-30 minutes. As one cell dies, another may develop nearby. Typical cell diameter 20 km: 3 stages of development: Thunderstorms occur when warm and moist air is lifted upward: mechanical lifting: cold, dense air undercuts warm, less-dense air, thermal lifting: warm, less-dense air flows up and over cold, dense air along a gentle slope. Condensation of water vapour release of latent heat . Cloud becomes warmer updraft of warm and moist air. Warm and moist air continues to rise as long as it is less dense than the surrounding air.
