ATMS 120 1st Edition Lecture 12 Outline of Last Lecture I Light and color perception by the human eye II Color III Blue skies IV Sunsets V Rainbows Outline of Current Lecture I Tropical cyclones II Hurricane tracks III Atlantic hurricane season Current Lecture I Tropical cyclones are called different things in different parts of the world Around North America they re referred to as hurricanes Around Eastern Asia they re called typhoons Around India and in the southern hemisphere around Australia they re called cyclones Around 80 tropical cyclones occur per year On average about 50 70 of them achieve hurricane strength meet the wind criteria Only 10 of tropical storms occur in the Atlantic Ocean and 66 of all tropical storms occur in the northern hemisphere No tropical cyclones occur on the equator because of the Coriolis effect It is impossible for a tropical cyclone to cross the equator Tropical cyclones in different hemispheres rotate in opposite directions No tropical cyclones form too far north or south of the equator because the waters are too cold There has only been one tropical cyclone tracked in the southern Atlantic Ocean near Brazil The reason tropical cyclones don t typically form in the southern Atlantic Ocean is because the waters are too cold and the change of wind speed and direction is too high In the northern hemisphere tropical cyclones spin counter clockwise In the southern hemisphere tropical cyclones spin clockwise II A typical hurricane near the United States travels in the same general track the hurricane moves from the east to the west and then curves to the north The hurricanes are steered These 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 westward by the trade winds They are turned north by the Coriolis Force and then circulated around the subtropical high pressure system Some hurricanes to note that did not have typical tracks are Hurricanes Kyle Ivan and Gordon III Hurricane season is June 1 December 1 This is when the sea surface temperatures in the Atlantic are warm enough September 10 is the peak of hurricane season Cape Hatteras has the most frequent hurricane strikes followed by Florida Hurricane Katrina hit the US twice it hit Florida before it hit New Orleans She was a Cat 3 in strength when she made landfall in New Orleans then increased to a Cat 5 She started as a tropical depression then strengthened into a tropical storm and hit Florida then strengthened into a Cat 1 upon landfall on Florida which is unusual because storms usually decrease in strength once they make landfall Hurricane Sandy was interesting because she made a hard left turn in her track which rarely ever happens