ASTRON 105 Study Guide - Centripetal Force, Pressure-Gradient Force, Weather Vane

• School: UMASS-Amherst
• Department: Astronomy
• Course: ASTRON 105
• Professor: Heath Hatch

Document Summary

Winds are the horizontal movement of air molecules. The direction of the wind is given as the direction from which the wind is coming. Wind direction is measured by a wind vane. Wind speed is measured by an anemometer. Wind speeds can also be measured using doppler radar. Air motion is produced by horizontal pressure gradients. Horizontal pressure gradients represent differences in pressure between one location and another, after accounting for differences associated with changes in elevation. The direction of pressure gradients is from high to low pressures, perpendicular to the isobars. The strength increases with decreasing distance between the isobars. Pressure gradients at the surface and aloft form when air is unevenly heated, creating thermal circulations. Sea and land breezes are examples of thermal circulations formed from unequal heating and cooling of land and water surfaces. Mountain and valley winds, santa ana, and foehn winds are other examples of local winds.