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)