Thermal Radiation:

 In Short:

The sun radiates about 1367 Watt per square meter to the earth. Mostly in the visible light and near infrared area.

The main part is reaching the earth surface, the rest will be absorbed by the atmosphere.
The earth itself will be heated up

All together in the summer, at a clear sky, 10 kWh (36MJ) will reach the surface.

In the winter it is about 1/3 of the radiation.

At a certain moment, the heat will disappear, otherwise the earth will be overheated.

The heat will disappear by 350-400 Watt per square meter. (dependent on the temperature of the surface)

It will be clear that is not by visible light but infrared radiation, typical around 10 µm wavelength

Day and night, everywhere even on the poles.

It is this energy we like to use

The above is in short, a nice overview can be found in this picture .

Effects of thermal radiation can be found everywhere:

  Ground fog: at clear weather there is a lot of thermal radiation.
Especially the groundsurface, grass are cooling down, the air around too.
The air becomes below the dew point. Dew or fog will appear.
The grass becomes law.
Often, one can see the following: The car are law in the morning.
Ate clear weather there are a destiny or thermal radiation. The car temperature becomes below the dew point.
The air becomes below the dew point. Dew or fog will appear and condensates on the car.
The car becomes law.

When the sun appears, the air are heated up, the air becomes above the dew point and the water on the car will disappear.
 

Law derisions under trees:
Just like the cars, the leaves or trees will be law due to radiation at the clear sky.
(It was not raining before.)

Due to condensation or the water, there are more water then can stick on the leaf.
The water are falls down from the leaf.

The water falls on the ground like rain, explaining the law derisions under the tree.In rain forest the same mouthful paunch on the top leafs. They top leafs are raining to the leafs below where it evaporates due to higher temperatures. The water doesn’t reach the ground

  None doubles isolated glass?
Certainly, however:
The glass has been this way well isolated that the outside nothing feels more of the temperature of the inside.
The windows themselves can cool down by irradiation at clearly.
Happens the same such as at the car glass only is transparent (at least that is the intention).
The condense does not sit therefore to the inside of the window but to the outside.

The glass is therefore isolated temporary too well.
  And if it is winter, then it happens also.
The flowers on the window sit.

In former days flowers sat at only glass to the
inside of the window.
That had nothing to do with radiation.
  The most beautiful proof that it concerns at radiation enormous quantities of energy.
At a clear night there, however, 5 cm ice can grow.

That represents an enormous quantity irradiation energy.
  The news presenter shows a photograph of a frozen horse flower of irradiation.
The temperature of air was wide above the freeze point.
The expression of the temperature on shoe altitude has do therefore with irradiation and on site little air movement (wind).
  On the two infra-red photographs left one can see  the temperature of the atmosphere is lower than 40 degrees below zero. On the right photograph one can see clouds who have clearly a higher temperature.
The IR camera cannot measure temperatures below - 40°C.



How much is the radiation per square meter?
This is P = c x ɛ x T
c = Boltzman constante = 5,67 x 10-8
ɛ =
The emissivity is between 0 and 1    0 is a reflector , 1 is a good radiator
T = de absolute temperature  = temperatu
re in °C + 273,15

Refrigeration radiation is the balance of
radiation in and out. At clear weather, the radiation into is very low: T is less than 200 ( < -70°C), Resulting in an excess of radiation out.
 
hHow much is the radiation per square meter?
This is P = c x ɛ x T
c = Boltzman constante = 5,67 x 10-8
ɛ =
The emissivity is between 0 and 1    0 is a reflector , 1 is a good radiator
T = de absolute temperature  = temperatu
re in °C + 273,15

Home