Water Cycle 1.Formulation of the hydrological cycle 2.Equations of Hydrology 3.Observations

Water Cycle

1. Formulation of the hydrological cycle

2. Equations of Hydrology

3. Observations

Formulation of the hydrological cycle

Global water content 13.1x1015kg (~2.5cm)Annual mean precipitation ~1mOverturning ~40 times/year (9 days)

Equations of HydrologyS=P-E-R0-Ru

S- rate of storage of waterP- precipitation rate (liquid and solid phase)E- evaporation rate

R0- surface runoff

Ru-subterranean runoff}R{-}E- P{}S{ 0

S {S}-time-averaging, -space-averaging

For large areas }S{ is small, thus }R{-}P{}E{ 0accuratelymeasuredmeasured

semiempiricestimates

Runoff

Balance Equations for Water Wapor

0

0

),,(p

g

dpqtW

PEQdivt

W

0

0

)(p

c g

dpvqqQ

qqc

t

WQdivSR }{0

]''[][]][[][**

vqvqvqqv

]''[][]][[][**

wqwqwqqw

-amount of precipitable water [g/m2]

-areal runoff,

-equation for the atmospheric branch of the hydrological cycle

PE couples land andatmospheric branches, thus

Globally E=P

-transport trough one parallel

-vertical transport

Water Wapor in the

Atmosphere(Horizontal

patterns)

Water Wapor in the

Atmosphere(Vertical patterns)

More than 50 percent ofthe water vapor isbelow 850mb (90 percentbelow 500mb)

NH: Summer-Winter1.2cm water

SH: Summer-Winter0.7cm water

Global meanwater content2.5cm

Transport of Water Vapor

Aerial Runoff