Billy_Bob
Diamond Member
Lets Do the Math on our Atmosphere...
LWIR can not warm our atmosphere directly as it can not interact with anything except water vapor, which can use the energy to warm itself in our atmosphere. IR heaters prove this out in testing as energy in the 12um-16um setting is incapable of warming O2, N2, CO2 and other atmospheric gases. This type of energy must interact with a Black Body or a Grey Body in order to warm anything (solid surface or water).
If you do the math on what little energy can interact with atmospheric gases, the input energy would have to be >5600w/m^2 just to raise the temp 1 deg C absent water vapor.(Roughly 4 times the output of our sun, in this narrow band, at TOA-[Top Of Atmosphere])
You only need to look at the band pass graph of our atmosphere to see why we would need this much energy to warm the mass of the atmosphere.
CO2 can not hold energy long enough to warm and it loses energy by collision some 30,000 times to 1 re-emission. Thus the energy is lost a long time before it has the potential to warm the molecule or any other molecule in our atmosphere. Absent water vapor LWIR is transparent to our atmosphere.
Many times I have pointed out our deserts and places of low water content, which have a 40% larger temperature swing and far faster rates of change than other areas of high water content. Most desert areas can cool to 32 deg F at night and be 110 deg F in the day time by 10 am and areas of high water content will get to 55 deg F at night and take until 3pm to reach 90 Deg F (much slower warming due to atmospheric loss and then cool slower due to warmer water in the atmosphere).
IF you note the power curve in the above graphing (green dotted line) you will begin to understand why the atmosphere can not warm with such a small bandwidth of LWIR and what little power it represents when you take that small region into account only.
ON to the math....
LWIR can not warm our atmosphere directly as it can not interact with anything except water vapor, which can use the energy to warm itself in our atmosphere. IR heaters prove this out in testing as energy in the 12um-16um setting is incapable of warming O2, N2, CO2 and other atmospheric gases. This type of energy must interact with a Black Body or a Grey Body in order to warm anything (solid surface or water).
If you do the math on what little energy can interact with atmospheric gases, the input energy would have to be >5600w/m^2 just to raise the temp 1 deg C absent water vapor.(Roughly 4 times the output of our sun, in this narrow band, at TOA-[Top Of Atmosphere])
You only need to look at the band pass graph of our atmosphere to see why we would need this much energy to warm the mass of the atmosphere.
CO2 can not hold energy long enough to warm and it loses energy by collision some 30,000 times to 1 re-emission. Thus the energy is lost a long time before it has the potential to warm the molecule or any other molecule in our atmosphere. Absent water vapor LWIR is transparent to our atmosphere.
Many times I have pointed out our deserts and places of low water content, which have a 40% larger temperature swing and far faster rates of change than other areas of high water content. Most desert areas can cool to 32 deg F at night and be 110 deg F in the day time by 10 am and areas of high water content will get to 55 deg F at night and take until 3pm to reach 90 Deg F (much slower warming due to atmospheric loss and then cool slower due to warmer water in the atmosphere).
IF you note the power curve in the above graphing (green dotted line) you will begin to understand why the atmosphere can not warm with such a small bandwidth of LWIR and what little power it represents when you take that small region into account only.
ON to the math....