GEOG 1900 Study Guide - Midterm Guide: Ice Pellets, Smog, Cumulonimbus Cloud
4 Oct 2018
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Document Summary
Hot air is less dense than cold air: air is distributed vertically in the atmosphere. It is compressible, meaning there is higher pressure near the surface than at higher elevations. Pgf (pressure gradient force) causes wind, ocean currents, and waves. The force is exerted from areas of high pressure to areas of low pressure. The larger the pg, the stronger the pgf, the stronger the wind. The coriolis effect acts to deflect movement: to the right, in the northern hemisphere, to the left, in the southern hemisphere. The intensity of the deflection is proportional to the speed of movement. It is zero at the equator and increases with latitude for a maximum effect at the poles. However, after 2 km above the surface it becomes negligible so when looking at winds in the upper atmosphere, we only take into account the pressure gradient and coriolis forces. Geostrophic winds are winds that have no net force acting on it.
