Hydrosphere Partitioning…
• Total = 1.36 x 109 km3 water
Earth’s water balance (Fluxes per year)
• Ocean Volume = 1.4x 109 km3
Oceanic Evaporation Rate = 3.2x105 km3/yr• Groundwater Volume = 8.4x106 km3(o.6%)• River+Lake Volume = 2x105 km3 (o.014%)• Atmosphere Volume = 1.3x104 km3
Runoff Rate = 3.6x104 km3/yr
89% of rain falls over oceans
• Land receives ~11% of ocean’s evaporation (36,000 km3)• 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
Residence times in ground, rivers, & atmosphere
Residence time defined as the
(Volume of ‘Reservoir’)/(Rate of flow through Reservoir)
For groundwater = 8.2x106 km3 / 3.74x104 km3/yr = 224 years
For rivers & lakes = 2x105km3 / 3.74x104 km3/yr = 5.3 years
For atmosphere = 1.3x104km3 / 3.8x105 km3/yr = 12 days
Biggest Rivers (11,205km3/yr; 31% of runoff)
River Drainage Area
(km2)
Discharge (km3/yr)
Amazon 5.78x106 5510 (half)
Congo 4.01x106 1250
Yangtze 1.94x106 687
Brahmaputra 9.35x105 624
Ganges 1.06x106 589
Yenisei 2.59x106 554
Mississippi 3.22x106 551
Orinoco 8.80x105 541
Lena 2.42x106 494
Parana 2.30x106 475
N.American Drainage Basins
Global Rain
Why do raindrops not grow to be huge?
Why do raindrops not grow to be huge?
They self-destruct once they grow too big!
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)
Atmosphere temperature & condensation
Stable Air
A mechanism to lift air/trigger condensation
Another way to lift air…(warm front)
Moderate Precipitation
~200 km
1/200
Different Variation (cold front)…
~100 km
1/100
Lifting-precipitation reason for climate belts
Global climate
Coriolis Force key influence on weather fronts & storms (Cyclonic effects)
Cyclonic Effects (Coriolis Revisited)
Mid-latitude cyclone
Life cycle of a thunderstorm
Condensation (rain) releases heat, fuels ascent
Unstable warm air rises
Downdrafts cut off fuel (warm air) & storm dies
A hurricane can circumvent this limit…
Hurricane wind & rain structure
Regions where hurricanes form…
Warm water = hurricance fuel.
Hurricane paths near US
Two Cyclones: What difference & why?
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.
New Orleans— Flooding from Hurricane Surge & Rain
Path of Katrina’s eye
New Orleans Experience — Flooding (Marshak Fig. 17.23)
Estimating Threat from Flooding (Recurrence Interval)
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