MET 1010 FINAL EXAM STUDY GUIDE THE ATMOSPHERE IN MOTION AIR PRESSURE FORCES AND WINDS vectors have magnitude and direction density mass volume pressure force area PGF P X pressure gradient force how rapidly a pressure changes with distance pressure in the atmosphere Mair n of molecules pressure always goes from low high hydrostatic balance pressure gradient and gravitational forces are balanced which gives us the atmosphere where FG FP WIND SMALL SCALE AND LOCAL SYSTEMS geostrophic wind wind when isobars are straight coriolis effect at right angles to the way the wind is blowing caused by rotation of the earth friction always acts in the opposite direction of wind zonal flow east west wind meridional flow north south wind microscale 1km or less individual thunderstorms and clouds mesoscale troposphere to stratosphere large thunderstorms fronts squall lines tropical cyclones synoptic scale large long lasting weather phenomena frontal zones extratopical cyclones sea breeze cool breeze that develops over coastal land WIND GLOBAL SYSTEMS easterly wind means it is coming from the east westerly from the west etc hadley ferrel and polar cells Polar cells are at the poles Hadley cells are at the equators Ferrel cells are in between El Ni o near the end of the calendar year a warm current of nutrient poor tropical water moves southward replacing the cold nutrient rich surface water La Ni a if trade winds are exceptionally strong unusually cold surface water moves over the central and eastern Pacific and the warm water and rainy weather is confined mainly to the western tropical Pacific no chapter 12 AIR MASSES AND FRONTS front a boundary between two different kinds of atmosphere often distinguished by temperature hint he will describe the weather and ask for what kind of front it is If it is cool before front and warms warm front If it is warm and gets cold cold front For occluded whichever of the fronts stays on the ground it is that ex If the warm front is on the bottom it is a warm occluded front note read articles on BB WEATHER FORECASTING persistence likelihood that the weather will continue to stay the same climatology likely to be around the average temperature if it rained today it probably won t tomorrow does not apply to summer thunderstorms in Florida which occur very often advection moving things around in the atmosphere dynamical or numerical forecasting using equations and computers THUNDERSTORMS AND TORNADOES three classes of thunderstorms air masses ordinary thunderstorms multi cell thunderstorms gust fronts and micro bursts supercell thunderstorms large and massive often reach up to stratosphere tornadoes usually rotate counterclockwise veers as you go up wind rotates south to west clockwise backing wind rotates counterclockwise as you go up vorticity rotation LIGHTNING forms by non inductive charging ice crystals hit graupel and electrons transfer the positively charged crystals go to the top of the cloud and the negatively charged graupel go to the bottom of the cloud the negatively charged cloud bottom is attracted to positively charged objects on the ground electrons bridge the gap between the cloud and something on the ground which is seen as lightning florida is 1 state for lightning and tornadoes because of hurricanes and thunderstorms HURRICANES have three names for the same thing but in different regions hurricane north atlantic typhoon west of mexico US cyclone southern hemisphere nomenclature of hurricanes alternating Spanish and English names alternating male and female names repeated every 6 years if name becomes a famous hurricane the name is retired typhoons tend to be larger than hurricanes there are very few cyclones mostly in Australia some in Brazil hurricanes are caused by an imbalance of heat atomic bomb 20 00 tons of TNT h bomb 5 megatons of TNT hurricane 10 000 5 megaton h bombs stages of hurricane formation energy stage 1 tropical disturbance collection of clouds stage 2 tropical storm 45 74 mph winds otherwise no different from a hurricane named and if it becomes a hurricane it keeps the name stage 3 hurricane 74 mph winds hurricane level windspeeds level 1 74 95 mph level 2 96 110 mph level 3 111 130 mph level 4 131 155 mph level 5 155 mph note wind speed measurements are innacurate recurvature when hurricanes tropical storms stop their westward movement and their path starts to turn northeast eye warm core low dry air intrusion is what kills hurricanes
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