January 14 lecture Flashcards
What is the Solar Constant?
The average energy flux from the sun at the mean radius of the earth ( 150 million km )
Is all the energy that comes to the earth absorbed?
No, some of it is reflected back out due Albedo.
What is Albedo?
the proportion of the incident light or radiation that is reflected by a surface, typically that of a planet or moon.
What is the Albedo of Earth?
0.30 ( although it varies greatly by location )
What is the Solar irradiance that the earth recivies with and without Albedo?
Wthout: 344 W m-2
With: 238 W m-2
Where are locations of high albedo?
In the High northen hemispheres
Where are locations of low albedo?
Around the tropics (equator)
What is the Surface temperature of the earth, as calculated by using solar constants?
it would be 255K or -18C
What is the Cause of deference between expected surface temperature and the actual surface temperature?
The greenhouse gas effect.
What is the greenhouse gas effect?
It is when gases and particles in our atmosphere trap the incoming radiation from the sun and lock it in.
How does the greenhouse gas effect work? ( two things )
- Incoming energy from the sun enters the atmosphere as short wave radiation, and as it passes through the atmosphere it becomes long wave radiation
- When this radiation is reflected from the surface and back out, the long wave radiation has a harder time going through the green house gases and is reflected back..
What is the main greenhouse gas?
Water Vapour
What is Net Heat Flux?
Net Heat Flux = SW + LW + Sensible + Latent
What is SW?
SW – incoming net short wave radiation
What is LW
LW – outgoing long wave radiation
What is Sensible?
Sensible – Flux of heat due to conduction
What is Flux heat due to Conduction/
The direct physical contact between the atmosphere and the ocean leading to energy exchange by conduction.
How does Atmosphere to ocean heat conduction work?
Energy is transferred to the cooler (and thus slower) molecules by molecular collisions in the ocean.
This is dependent on the air-sea (or land)
temperature difference and wind-speed
What is Latent?
Latent – latent heat exchange
What is Latent heat exchange?
When water is evaporated, energy is supplied to the molecules to free them from the strong bonds in liquid
water
What happens when water molecules condense to form water droplets?
They release energy in the form of heat to its surroundings.
What is latent heat exchange dependent upon?
It is heavily dependent upon temperature
How does temperature affect latent heat exchange?
The higher the temperature, the more moisture air can hold and
therefore the greater potential for latent heat release upon
condensation
What are the Heat properties of water?
- Has a very high heat capacity
How does waters Latent heat affect the ocean?
Waters latent heat has a huge affect on the oceans stroage and transport f heat as well as the climate as a whole
In the polar regions how is heat exchanged?
Through latent heat exchange,
Water Cooling in the winter and warming in the summer
What does it mean if the polar region is dominated by latent heat exchange?
Means that there is very little change in temperature over the course of the year
What does the high latent heat of vaporization affect?
The transport of heat in the atmosphere.
Hows dose evaporation in the tropics affect the heat at the polar regions?
Heat is added to the tropics, which warms theater and leads to evaporation. this heat is stored in the water vapor molecules, which are blow to higher latitudes, where they condense into rain.
Thus the heat in those water molecules is released to the atmosphere, warming the higher latitudes.
Is solar radiation evenly distributed across the earth? Why?
No, There is a net surplus of radiation on the tropics and is deflected at high latitudes.
Due to how radiation is distributed across the earth, how is heat transported?
transport of heat
by the oceans and atmosphere
from the equatorial regions to
the poles
What is the main driving force behind oceanic and atmospheric circulation?
The redistribution of heat from the equator to the poles.
What is the reason behind why the equator has a net radiation gain and the poles do not? ( 3 things )
1) Angle of impact of solar radiation
2) Earths surface area
3) Atmospheric path length
What is Albedo? what does it measure?
This value measures the ratio of reflected incoming radiation.
What are the five things that mainly control ocean surface water properties?
- Solar radiation
- Transfer of heat and water with the atmosphere
- Ocean currents
- Vertical mixing
- runoff
