#15 hurricanes

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A powerpoint about Hurricanes and their effects.

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  • Hurricanes

    Lets get our noses off the ground and look back to the skies

    Tropical Cyclone- A low pressure storm surrounded by rotating windsy Called Hurricanes in the Atlantic & Eastern

    Pacificy Called Typhoons in the Western Pacific and

    Asia

    Form over warm seawater (25C+) and between ~5 and 20 latitude.

    GSC 350Natural Disasters

  • Global Wind Patterns

    See Ch.10 pg. 265 Wind patterns have relationship to

    position onthe globe

    Latitudedependant(North/South)

    Know this

    GSC 350Natural Disasters

  • Global Wind Patterns

    Recall highs and lows

    Equatorial low (0)

    Subtropical high (30)

    Trade winds (SW)

    Westerlies(NE)

    GSC 350Natural Disasters

  • Global Wind Patterns

    Coriolis Effect- Deflection of an object (air mass) in a direction due to rotation (right in the Northernhemisphereand left inthe Southern)

    This leads toa shearing directionalityof air masses

    GSC 350Natural Disasters

  • Hurricanes GSC 350Natural DisastersNorthern Hemisphere Southern Hemisphere

  • Hurricanes GSC 350Natural DisastersCounter Clockwise Clockwise

  • Hurricanes GSC 350Natural Disasters Form within the trade winds, disperse

    within the westerlies

  • Hurricanes GSC 350Natural Disasters

    Hurricanes contain rising moist warm air rotating into the center (eye)

    The Eye is a low pressure zone in the center of the storm where warm wet air rotates around and dry cool air descends into

    The eye is calm, butthe strongest windsexist within its walls

  • Hurricanes GSC 350Natural Disasters

    200km+ wide (diameter), eye ~20km

  • Hurricanes GSC 350Natural Disasters

    Approaching the eye, wind velocities increase, pressure drops(figure 14-2 pg.417)

    Once inside eye, windvelocities are zero

    Consider as a stormpasses over you andyou are within theeye, what will happennext?

  • Hurricanes GSC 350Natural Disasters

    We classify hurricanes based upon wind speed and barometric pressure

    Saffir-Simpson Scale- divides hurricanes into 5 categories (1 weakest, 5 strongest)

    Category Pressure (mbar) Surge (ft) Wind (mph)

    1 >980 4-5 75-95

    2 965-979 6-8 96-110

    3 945-964 9-12 111-130

    4 920-944 13-18 131-155

    5 18 >155

  • Hurricanes GSC 350Natural Disasters

    Damaging products of hurricanes-y Storm Surge- Due to low pressure and high

    winds, sea level rises with hurricane

    y Wind and Rain- produced by storm, can cause damage and flooding (along with surge)

  • Hurricanes GSC 350Natural Disasters

  • Hurricane Case Study GSC 350Natural Disasters

    Typhoon Haiyan (Yolonda) November 2013y Category 5y Max winds- 195mphy Pressure- 895 mbary Storm surge- 17fty Rainfall- 11in+ (12hr)

    Landfall in thePhilippinesNovember 7th

    Well defined eye

  • GSC 350Natural DisastersHurricane Case Study

  • GSC 350Natural Disasters

    4,000+ confirmed deaths Estimated damage

    ~1.1billion USD Philippine warnings

    issued prior to stormlandfall

    Entire cities destroyed Waves/ storm surge were major culprit in

    damage/ loss of life

    Hurricane Case Study

  • GSC 350Natural Disasters

    Aftermath?

    Hurricane Case Study

  • EXTRA CREDIT GSC 350Natural Disasters

    Field trip this Sunday (November 24th)y Meeting 8:00am at San Antonio Damy We will be done by lunch timey Forms to sign on Thursdayy Short 1 page summary due Dec. 5th

    Exercise #2 (requires Excel)y Assignment due Dec. 5th

    One or the other, will be no more than 5% of your grade

    Map

  • Next Time GSC 350Natural Disasters

    We will skip risk and mitigationy We have touched on these topics throughout the

    quarter

    Last assignment (Exercise #15)y Review floods

    Recurrence intervals (understand how to calculate) Hydrographs (know what you are looking at)

    Tamara will lecture on global warming

    Midterm Review (Midterm 11/26)

    HurricanesHurricanesGlobal Wind PatternsGlobal Wind PatternsGlobal Wind PatternsHurricanesHurricanesHurricanesHurricanesHurricanesHurricanesHurricanesHurricanesHurricanesHurricane Case StudyHurricane Case StudyHurricane Case StudyHurricane Case StudyEXTRA CREDITNext Time