EARTH 20 Lecture Notes - Lecture 13: Enhanced Fujita Scale, Funnel Cloud, Vertical Draft
Document Summary
**note**: composition of atmosphere pie chart includes only permanent gases (not water, which is actually the most important greenhouse gas) Mainly in afternoons/evenings (warmest part of day) during spring/summer (warmest part of year) Form along cold fronts: colder air mass plows under warm moist air mass, forcing warm air up. Rising warm air causes condensation of water vapor. Latent heat released > more rise of air some rain produced. Updraft continues: heavier rain, lightning and thunder, hail. Downdraft blocks upward supply of moist air > storm weakens. Updraft of moist warm air in lower atmosphere into dry higher air in atmosphere. Supercell storms: upwards spiraling of column of air (mesocyclone) Vertical wind shear: as a result of either changes in: Wind direction: ex clouds going in opposite directions. Velocity: higher above the ground, the less resistance/higher velocity. Results in barrel-like flow on earth"s surface. Wind shear develops horizontally between faster and slower winds.
