GEOG-120 Lecture Notes - Lecture 27: Pressure-Gradient Force, Coriolis Force, Pressure Gradient
24 Sep 2020
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Document Summary
Force (per unit area) exerted by weight of a column of air. Typically measured with a barometer- mb or kpa. Varies slightly (~5%) but small differences can be significant. Wind is air in (predominantly) horizontal motion. Greater pressure difference create faster wind speeds. Heating of air at x causes air to expand and push isobaric surface upward. Because pressure is increases, air begins to flow from point x to a and b. Direction of air motion also affected by earth"s rotation. Air (and water) move as though being pulled sideways. Deflects to right in north, to left in south. Magnitude of deflection increases with speed of air/ocean currents and distance from the equator. Wind direction is the result of the three forces acting together (generally across. Mean monthly atmospheric pressure and prevailing surface winds) Cyclones (low pressure centers) are associated with cloudy or rainy weather. Air converges, rises, cools and condenses into cloud.
