GEOG 101 Lecture Notes - Lecture 31: Wind Speed, Coriolis Force, Geostrophic Wind
Document Summary
Air pressure on upper-level weather maps is labelled using isoheights. The height in meters that one must travel upward to reach the 500 hpa pressure level. On upper level maps the highs and lows are in purple rather than red/blue. Its saying you have to travel 5700m, in this example, to hit a pressure of 500 hpa. In the south it"s warm/north it"s cold. Thus we have to travel through more air to reach. Thus we need to travel less to reach those altitudes. Isoheights can help us determine where the jet streams are located. An upward bend in the isoheights around high pressure. A downward bend in the isoheights around low pressure. Ridges say warm air is being pumped up, trough tells us where the cold air is sinking. Upper-level maps are needed to forecast the weather. Whether surface systems will intensify or weaken. There are 4 forces that affect the velocity and direction of wind:
