1. Rossby Waves

5. Tropopause variation with latitude

6. Jet stream – wind field and temperatures

7. Isotachs and isotherms

8. Mid-latitude Cyclones Formation revisited

9. Polar front

10. Upper atmosphere pressure and winds

13. Current circulation model

14. Tropical Climate

15. Monsoon

16. Asian monsoon - 1 Winter (northern hemisphere) Cold air over Asia creates high pressure. Dry air drawn southwards from Himalaya

17. Asian monsoon - 2 Summer (northern hemisphere) Land heats to give low pressure over Asia. Moist air drawn northwards from equatorial oceans

19. Hurricane Mitch

20. Distribution of Hurricanes

21. Hurricane Damage Scale Number Category Central Pressure mb inches Wind Speeds mi/hr knots Storm Surge feet meters Observed Damage 1>=980 >=28.94 74-95 64-82 4-5 ~1.5 some damage to trees, shrubbery, and unanchored mobile homes 2965-979 28.50-28.91 96-110 83-95 6-8 ~2.0-2.5 major damage to mobile homes; damage buildings' roofs, and blow trees down 3945-964 27.91-28.47 111-130 96-113 9-12 ~2.5-4.0 destroy mobile homes; blow down large trees; damage small buildings 4920-944 27.17-27.88 131-155 114-135 13-18 ~4.0-5.5 completely destroy mobile homes; lower floors of structures near shore are susceptible to flooding 5<"920" <"27.17" >"155" >"135" >"18" >"5.5" extensive damage to homes and industrial buildings; blow away small buildings; lower floors of structures within 500 meters of shore and less than 4.5 m (15 ft) above sea level are damaged

22. Hurricane Eye Wall

23. Cross-section of hurricane

24. Spin up process Air converges from radius of order 1000 km Air that is stationary w.r.t. the earth is travelling eastwards w.r.t. a frame of reference fixed in space at a speed Hence air drawn from N travels more slowly and that from S faster than the centre of the hurricane, leading to rotation. convergence rising air, condensation release of latent heat surface low pressure R θ Ω relative to space Conserving angular momentum about eye mvr is constant so: relative to earth