1. Three Lectures on Tropical Cyclones Kerry Emanuel Massachusetts Institute of Technology Spring School on Fluid Mechanics of Environmental Hazards

2. Lecture 1: Observed Characteristics

3. What is a Hurricane? Formal definition: A tropical cyclone with 1-min average winds at 10 m altitude in excess of 32 m/s (64 knots or 74 MPH) occurring over the North Atlantic or eastern North Pacific

4. The word Hurricane is derived from the Mayan word Huracan and the Taino and Carib word Hunraken, a terrible God of Evil, and brought to the West by Spanish explorers

5. Illustration from Travels in the West Indies, Theodor DeBry

6. Early historical encounters: The Mongol invasions of Japan in 1274 and 1281 Scene from the 13th century Mongol invasion scrolls, based on a narrative written by the Japanese warrior Takezaki Suenaga.

7. The View from Space

15. Airborne Radar: Horizontal Map 360 km (220 mi)

16. 120 km 20 km (12 mi) (75 mi) Airborne Radar: Vertical Slice

18. Azimuthal wind

19. Temperature perturbation at constant altitude

21. Radial wind

22. Vertical velocity

23. Angular momentum per unit mass

27. Tracks of all tropical cyclones, 1985-2005 Source: Wikipedia

29. Annual Cycle of Tropical Cyclones

33. Better Intensity Metric: The Power Dissipation Index A measure of the total frictional dissipation of kinetic energy in the hurricane boundary layer over the lifetime of the storm

34. Atlantic Storm Maximum Power Dissipation (Smoothed with a 1-3-4-3-1 filter) Power Dissipation Index (PDI) Years included: 1870- 2006 Data Source: NOAA/TPC

35. Atlantic Sea Surface Temperatures and Storm Max Power Dissiaption (Smoothed with a 1-3-4-3-1 filter) Scaled Temperature Power Dissipation Index (PDI) Years included: 1870- 2006 Data Sources: NOAA/TPC, UKMO/HADSST1

36. Socio-Economic Consequences of Hurricanes

37. Windstorms Account for Bulk of Insured Losses Worldwide

39. Source: Roger Pielke, Jr. Total U.S. Hurricane Damage by Decade, in 10 10 2004 U.S. Dollars

40. Population of Florida, 1790-2004

41. Source: Roger Pielke, Jr. Total Adjusted Damage by Decade, in 10 10 2004 U.S. Dollars

42. Total Number of Landfall Events, by Category, 1870-2004

43. U.S. Hurricane Damage, 1900-2004,Adjusted for Inflation, Wealth, and Population

44. Infamous Tropical Cyclones

45. Galveston, 1900

46. East Pakistan, 1970

48. Hurricane Katrina, 2005