Slide 1

Hydrosphere Partitioning Total = 1.36 x 10 9 km 3 water Slide 2 Earths 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 Slide 3 89% of rain falls over oceans Land receives ~11% of oceans 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 Slide 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 Slide 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 Slide 6 N.American Drainage Basins Slide 7 Global Rain Slide 8 Why do raindrops not grow to be huge? Slide 9 Why do raindrops not grow to be huge? They self-destruct once they grow too big! Slide 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) Slide 11 Atmosphere temperature & condensation Slide 12 Stable Air Slide 13 A mechanism to lift air/trigger condensation Slide 14 Another way to lift air(warm front) Moderate Precipitation ~200 km 1/200 Slide 15 Different Variation (cold front) ~100 km 1/100 Slide 16 Lifting-precipitation reason for climate belts Slide 17 Global climate Slide 18 Coriolis Force key influence on weather fronts & storms (Cyclonic effects) Slide 19 Cyclonic Effects (Coriolis Revisited) Slide 20 Mid-latitude cyclone Slide 21 Life cycle of a thunderstorm Condensation (rain) releases heat, fuels ascent Unstable warm air rises Downdrafts cut off fuel (warm air) & storm dies Slide 22 A hurricane can circumvent this limit Slide 23 Hurricane wind & rain structure Slide 24 Regions where hurricanes form Warm water = hurricance fuel. Slide 25 Hurricane paths near US Slide 26 Two Cyclones: What difference & why? Slide 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 Katrinas eye N.O. Slide 28 New Orleans Flooding from Hurricane Surge & Rain Path of Katrinas eye Slide 29 New Orleans Experience Flooding (Marshak Fig. 17.23) Slide 30 Estimating Threat from Flooding (Recurrence Interval)