EESA09H3 Lecture Notes - Lecture 4: Natural Disaster, High Speed 1, Sea Surface Temperature
3 Jun 2018
School
Department
Course
Professor
Terms for Tropical Cyclones
1) Hurricane
• Tropical cyclones
• 0-20/30 degrees N or S
2) Typhoon
• Western Pacific
• tai Fug= ig id
Originating from Australia and Indian Ocean are termed as cyclones.
Definitions
Tropical cyclones – originate in the tropical latitude (0-30 degrees N and S)
Tropical storm – birth of hurricane in the tropical region (18 – 33m/s)
Hurricane- tropical storm (33-50 m/s)
Major hurricane - tropical storm exceeding 50m/s
Saffir-Simpson Scale – to categories hurricane
Tropical Storm Classification
• Uses Saffir-Simpson scale that categories from 1-5
• Irma was category 4 hurricane; huge energy due to low center pressure and high speed
1) Category 1 hurricane (33-42.5 m/s) >980mb
2) Category 2 hurricane (42.5-49m/s) 965-979mb
3) Category 3 hurricane (49-58m/s) 945-964mb
4) Category 4 hurricane (58-69m/s) 920-944mb
5) Category 5 hurricane (>69m/s) <920mb
As there is a decrease in center pressure, the more powerful the hurricane.
Dynamics= mechanism of the formation of hurricane
• Tropical storms will always form on oceans
• They are fueled by sea temperatures
• Threshold is 26.5 degrees celcius
• Need convergence on the surface and divergence aloft
• Center pressure is dropping and warm is rising
• Near the ITCZ
• June-November
• Warm core of the hurricane is known as the eye of the hurricane (linked to sinking air)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Terms for tropical cyclones: hurricane, tropical cyclones, 0-20/30 degrees n or s, typhoon, western pacific (cid:862)tai fu(cid:374)g(cid:863)= (cid:271)ig (cid:449)i(cid:374)d. Originating from australia and indian ocean are termed as cyclones. Tropical cyclones originate in the tropical latitude (0-30 degrees n and s) Tropical storm birth of hurricane in the tropical region (18 33m/s) Tropical storm classification: uses saffir-simpson scale that categories from 1-5, category 1 hurricane (33-42. 5 m/s) >980mb. Irma was category 4 hurricane; huge energy due to low center pressure and high speed: category 2 hurricane (42. 5-49m/s) 965-979mb, category 3 hurricane (49-58m/s) 945-964mb, category 4 hurricane (58-69m/s) 920-944mb, category 5 hurricane (>69m/s) <920mb. As there is a decrease in center pressure, the more powerful the hurricane. What affects the length and strength of the tropical cyclone: sea surface temperature- the warmer the ocean surface, the stronger and longer the storm more latent, upper wind structure- hamper the system; inhibit tropical cyclone longevity; weak hurricane.
