3.Evaporation Flashcards
Simplest form of evaporation is..
freewater evaporation
- when water molecules are only in contact with other water molecules
- ex: S Sask River
Evaporation from free water surfaces is promoted by:2
– External or meteorological factors
– Internal or lake factors
Evaporation from bare soil surfaces is promoted by :2
– External or meteorological factors
– Soil factors
Evaporation from vegetated surfaces is promoted by:3
– External or meteorological factors
– Soil factors
– Vegetation factor
3 External Factors promoting evap
3 Internap Factors Promoting Evap
• External factors
– Solar energy
– Humidity
– Diffusion and advection
• Internal factors – Salinity
– Water depth
– Surface area
.water vapour is constantly experiencing both upforce by _______ and downforce by _______
-how big they are relative to each other determines evaporation
vapourization
condensation
(Solar Radiation/Temperature) _______ is the best way to predict evaporation over time
Insolation
- radiation gives you the amount of available energy
- temperature does not drive evaporation
Why are the great lakes not as dependent on insolation for evaporation?
The great lakes store a lot of energy
-it means that they are not as dependent on incoming energy
Why do evaporation lines extend south over the cordillera?
lines of evaporation over cordillera bend south because of the mountains’ altitude
-higher altitude means lower evap
______ determines insolation which determines _____
latitude
evaporation
.water evaporates _____ in dry air
.water evaporates _____ into humid air
fastslow
Southern most points of canada experience about ___klyper year of insolation
40
Relative humidity has an _____ pattern to temperature
inverse
Evaporation from free water surfaces is affected by 3 external and 3 internal factors: be specific
- External factors – Solar energy – Humidity – Diffusion and advection
- Internal factors – Salinity – Water depth – Surface area
Dalton’s Law of Evaporation
E = f(u) (esat – eact)
E is the evaporation rate (cm day-1) f(u) is a function of the wind speed u esat is the saturated vapour pressure at the temperature of the water surface (mb) eact is the actual vapour pressure at the at thetemperature of the air (mb) u is the windspeed (km day-1) f(u) = 1.46 x 10-4 u
How does wind allow for more evaporation?
Advection takes place with wind
-it DISPERSES the humid air from the surface allowing for more evaporation
– Redistribution of large volumes of air
– Mixing of high humidity and low humidity air