1. Hydrosphere Partitioning… Total = 1.36 x 10 9 km 3 water

2. Earth’s water balance (Fluxes per year) Ocean Volume = 1.4x 10 9 km 3 Oceanic Evaporation Rate = 3.2x10 5 km 3 /yr Groundwater Volume = 8.4x10 6 km 3 (o.6%) River+Lake Volume = 2x10 5 km 3 (o.014%) Atmosphere Volume = 1.3x10 4 km 3 Runoff Rate = 3.6x10 4 km 3 /yr

3. 89% of rain falls over oceans Land receives ~11% of ocean’s evaporation (36,000 km 3 ) Twice as much water evaporates (&transpires) from land as runs off it e.g. rain on land falls three times on average before it gets back to sea

4. Residence times in ground, rivers, & atmosphere Residence time defined as the (Volume of ‘Reservoir’)/(Rate of flow through Reservoir) For groundwater = 8.2x10 6 km 3 / 3.74x10 4 km 3 /yr = 224 years For rivers & lakes = 2x10 5 km 3 / 3.74x10 4 km 3 /yr = 5.3 years For atmosphere = 1.3x10 4 km 3 / 3.8x10 5 km 3 /yr = 12 days

5. Biggest Rivers (11,205km 3 /yr; 31% of runoff) RiverDrainage Area (km 2 ) Discharge (km 3 /yr) Amazon5.78x10 6 5510 (half) Congo4.01x10 6 1250 Yangtze1.94x10 6 687 Brahmaputra9.35x10 5 624 Ganges1.06x10 6 589 Yenisei2.59x10 6 554 Mississippi3.22x10 6 551 Orinoco8.80x10 5 541 Lena2.42x10 6 494 Parana2.30x10 6 475

6. N.American Drainage Basins

7. Global Rain

8. Why do raindrops not grow to be huge?

9. Why do raindrops not grow to be huge? They self-destruct once they grow too big!

10. Atmosphere temperature & condensation Adiabatic effects on rising and sinking air: Air cools when it rises & is decompressed. Air warms up when it descends & is compressed. (reason why a bike pump gets hot when pumped)

11. Atmosphere temperature & condensation

12. Stable Air

13. A mechanism to lift air/trigger condensation

14. Another way to lift air…(warm front) Moderate Precipitation ~200 km 1/200

15. Different Variation (cold front)… ~100 km 1/100

16. Lifting-precipitation reason for climate belts

17. Global climate

18. Coriolis Force key influence on weather fronts & storms (Cyclonic effects)

19. Cyclonic Effects (Coriolis Revisited)

20. Mid-latitude cyclone

21. Life cycle of a thunderstorm Condensation (rain) releases heat, fuels ascent Unstable warm air rises Downdrafts cut off fuel (warm air) & storm dies

22. A hurricane can circumvent this limit…

23. Hurricane wind & rain structure

24. Regions where hurricanes form… Warm water = hurricance fuel.

25. Hurricane paths near US

26. Two Cyclones: What difference & why?

27. New Orleans Experience Hurricane surge (wind-driven waves was up to 28ft above sealevel — new record for US) Why were Mississippi & Alabama also severely affected, but not Texas? Path of Katrina’s eye N.O.

28. New Orleans— Flooding from Hurricane Surge & Rain Path of Katrina’s eye

29. New Orleans Experience — Flooding (Marshak Fig. 17.23)

30. Estimating Threat from Flooding (Recurrence Interval)