GEOB 102 Lecture Notes - Lecture 16: Fujita Scale, Downburst, Mesocyclone

• School: UBC
• Department: Geographical Biogeosciences
• Course: GEOB 102
• Professor: Nina Hewitt

Document Summary

There is lifting that builds cloud (could be frontal/convective/orographic), liberates latent heat energy. Updrafts: air pulled up and into a cloud, generated as a positive feedback mechanism, causes difference in pressure. When it falls, it creates downdrafts (because the friction of falling air drops is dragging air down with them) Downdrafts: frictional drag with heavy rain, hail, deadly downbursts (severe situations) Downbursts: winds that are extremely fast and spreading outwards while blasting horizontal wind beneath the downburst. Eventually downdrafts would become a negative mechanism, in order to have lifting (so that there would be continuous energy into the cloud) --> has a distinctive life. Anvil top --> function of wind shear high in the atmosphere, that may be due to geostrophic winds. Hail --> associated with thunderstorms, essentially frozen rain that is created in a cycle associated with updrafts and downdrafts. There is lifting that produces moisture that creates rain, which then accumulates water and freezes.