Geology 1350 Lecture 18 Outline of Last Lecture I. ThunderstormsII. TornadoesOutline of Current Lecture I. HurricanesII. Global climateCurrent LectureCh.11Hurricane-In the spiral of hurricane it is a rain free area, winds are greater than 33m/s, counterclockwiseNames of hurricanes- hurricane-atlantic or the eastern pacific ocean; typhoons(Taiwan)-western north pacific and Philippines; cyclones- indian and south pacific oceanTropical weather and waves- hurricanes usually come from west coast, no hurricanes along equator b/c Coriolis force is too small, water temp has to be greater than 27c degrees, occur over sea not over continent because land weaken hurricane and causes rain, usually occur b/n5-20 lat, tropical winds typically blow from the east and when they encounter a slow moving trough of low pressure called a tropical wave the winds uplift and cause rainHurricane wind profile- downdraft will evaporate the clouds, low pressure core of the hurricane is surrounded by several thunderstorms each updraft and downdraft cycles, the wind and moisture cycle is repeated as surface moist air converges in a counterclockwise pattern at the eye rises to create high pressure aloft condenses precipatesWarm ocean temp-t-storm,rising motion, condensation, precipatiationHigh relative humidity throughout low tropospher- less evaporation more condensation more precipation and more latent heat releaseThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.When wind shear is weak the storms that are part of the cyclone grow vertically and the latent heat from condensation is released into the airStages of development- tropical disturbance, tropical depression winds >20 knots no eye, tropical storm > 35 knots doesn’t spin, hurricane winds> 64 knotsUltimate source of energy for hurricanes is heat and moisture.Why hurricanes weaken rapidly when they travel over land or colder ocean: insufficient heat and or moisture, increased friction over landHurricane movement- global patterns of tropical cyclone formation and movement have been recorded on this figure which notes regional names for these systems, travel speeds for the hurricane my range from 10 to 15 knots. But they may also stall over a region and cause destructive flooding.Ch.12Globate climate- controlled by intensity of sunshine and its variation with latitude, distribution of land and water, ocean currentsRegions of rising and sinking air- global patterns of temp and precipitaion are affected by global cells of rising and sinking air which run meridionally north to southObserved rain vs ideal- n to s patterns of rising and sinking air Topography controls on climate westerly wind blowing moist air from pacific coastClimate classification – ancient greeks 3 regions tropical, polar, and temperate zonesTropical wet climate- monthly rain has greater variation than temp often only within 3c in thistropical wet climate a fact that is supported by the migrating pattern of the ITCZ ex; IquitosTropical wet and dry climate- greater variation in temp that at the equator annual rain may still exceed 100 cm but there is greater monthly variation in rain with 2 months less than 6 cmArid climate- approximately 12 % global lands are arid hot in summer and cool in winter, humidity is below 25 % low rainSemi-arid climate- some sort of rain in specific time of year, cold during winterHumid subtropical climate- hot in summer rain all over the place not big difference of temp during the rainMarine climate- low clouds fog and drizzle , cool in summer winter is not cold rain all the timeMediterranean climate- cali, no rain in summer, temp is boring same all the time b/c is inland Humid continental differences- rain in summer and warmer, winter is cold CanadaSubpolar and polar climate- fair banks, avg temp drier not much rain always coolPolar ice cap- Greenland, summer is cold, winter is fresh, not much rainVertical climate change- ascending a mountain brings changes in temp and rain and so it will bring changes in vegetation types and micro