Does a non-GHG Atmosphere warm a Planet?

[IanC]

Physics consists of using basic principles to get closer and closer to the truth.

To our CO2 Greenhouse Effect deniers- do you believe that a total N2 atmosphere would cause a rock planet to be warmer on average than without an atmosphere ? Why?

If you come to the reasonable conclusion that the atmosphere moderated surface temperatures by storing energy when the surface is warming and then releasing energy when the surface is cooling, then we have the first step.

 

[flacaltenn]

Physics consists of using basic principles to get closer and closer to the truth.

To our CO2 Greenhouse Effect deniers- do you believe that a total N2 atmosphere would cause a rock planet to be warmer on average than without an atmosphere ? Why?

If you come to the reasonable conclusion that the atmosphere moderated surface temperatures by storing energy when the surface is warming and then releasing energy when the surface is cooling, then we have the first step.

There would be no radiative emission to speak of. So all "heat transfer" would be largely from convection and pressure heating. Not sure where you're going with this because the all N2 layer would be mostly TRANSPARENT to solar incoming and black body outgoing IR transfer..

(If N2 molecules become superhot -- they do have IR emission/absorption bands due to atomic disassociation and reconstruction). IIRC....

 

[IanC]

Hi Flac. Hope you had a great Holidays and all the best for the New Year.

Where am I headed with this? I'm not sure. Hopefully there will be more like you that realize the radiation aspect has vanished but warming still occurs (by moderation of extremes).

The surface warms and cools primarily by solar radiation input and terreterrestrial infrared output.

The N2 atmosphere only heats and cools by conduction at the surface boundary. I'm not even sure if convection would be in action.

The important thing to take away is the unequal heating and cooling rates for the surface and atmosphere. Actually the atmosphere ONLY loses energy back to the surface.

 

[Billy_Bob]

Actually the atmosphere ONLY loses energy back to the surface.

This is crap Ian...

You have drank the whole dang cooler of Koolaid.. .

An N2 atmosphere is transparent to 99.9% of all EM radiation. It will not warm to pass through energy. ONLY convection and conduction at the surface will warm this environment and then only slightly above that of the temperature of space. Once the the suns energy is gone it will cool very rapidly as it can not hold energy. What little energy is absorbed by the atmosphere will be emitted to space very quickly as there is nothing to stop it in the atmosphere. Its mass is incapable of holding energy for more than 1-2 seconds.

 

[IanC]

An N2 atmosphere is transparent to 99.9% of all EM radiation. It will not warm to pass through energy. ONLY convection and conduction at the surface will warm this

So far, so good.

N2 atmosphere does not interact with any IR from the surface , and any SW solar absorbed cannot be remitted because the N2 is far too cold. Only conduction at the surface/atmosphere boundary warms and cools the N2 atmosphere.

 

[IanC]

Once the the suns energy is gone it will cool very rapidly as it can not hold energy. What little energy is absorbed by the atmosphere will be emitted to space very quickly as there is nothing to stop it in the atmosphere. Its mass is incapable of holding energy for more than 1-2 seconds.

Then you go off the rails.

How does the atmosphere lose energy to space? N2 neither absorbs nor emits IR.

The N2 indefinitely holds on to its stored energy simply by staying in a gaseous phase, suspended in the gravity field. During daylight the surface inputs energy to the atmosphere, which is then returned at night.

 

[CrusaderFrank]

What would Earth temperature be if CO2 were 0%?

How close to absolute zero would we come in exchange for the climate never changing?

 

[IanC]

What would Earth temperature be if CO2 were 0%?

How close to absolute zero would we come in exchange for the climate never changing?

Interesting. Are you implying that CO2 has a large warming effect?

 

[SSDD]

There are a few planets in the solar system which have no so called greenhouse gasses to speak of...at atmospheric pressures equal to earth, accounting for difference in incoming radiation, they are similar to earth...at higher pressures, they become quite warm...

 

[SSDD]

Once the the suns energy is gone it will cool very rapidly as it can not hold energy. What little energy is absorbed by the atmosphere will be emitted to space very quickly as there is nothing to stop it in the atmosphere. Its mass is incapable of holding energy for more than 1-2 seconds.

Then you go off the rails.

How does the atmosphere lose energy to space? N2 neither absorbs nor emits IR.

The N2 indefinitely holds on to its stored energy simply by staying in a gaseous phase, suspended in the gravity field. During daylight the surface inputs energy to the atmosphere, which is then returned at night.

N2 certainly emits the energy it absorbs via collisions with other molecules...it conducts till such time as it can't, then it radiates till it reaches its equilibrium temperature...ditto for O2 and argon...

You like to claim that every thing radiates till it becomes inconvenient then N2 doesn't radiate? How quaint.

 

[Olde Europe]

How does the atmosphere lose energy to space? N2 neither absorbs nor emits IR.

The N2 indefinitely holds on to its stored energy simply by staying in a gaseous phase, suspended in the gravity field. During daylight the surface inputs energy to the atmosphere, which is then returned at night.

An N₂ atmosphere can lose energy to space in case very hot molecules escape the planet's gravity. Otherwise, no. That's probably negligible.

I think you are right. Conduction warms the near-surface atmosphere during the day, and gives back during the night. Once equilibrium is established, the absorbed and returned energy need to be equal. That means, the planet's average temperature should be equal to a planet with no atmosphere, but the day / night extremes are somewhat moderated. Also, I think, convection plays a role in that the equator / pole temperature difference should be somewhat lower with, compared to without, atmosphere.

 

[Billy_Bob]

How does the atmosphere lose energy to space? N2 neither absorbs nor emits IR.

The N2 indefinitely holds on to its stored energy simply by staying in a gaseous phase, suspended in the gravity field. During daylight the surface inputs energy to the atmosphere, which is then returned at night.

An N₂ atmosphere can lose energy to space in case very hot molecules escape the planet's gravity. Otherwise, no. That's probably negligible.

I think you are right. Conduction warms the near-surface atmosphere during the day, and gives back during the night. Once equilibrium is established, the absorbed and returned energy need to be equal. That means, the planet's average temperature should be equal to a planet with no atmosphere, but the day / night extremes are somewhat moderated. Also, I think, convection plays a role in that the equator / pole temperature difference should be somewhat lower with, compared to without, atmosphere.

N2 has a very low energy residency time, even lower than that of O2 and CO2. ITs the mass of these and the very narrow regions that LWIR can affect which determine the energy it can store and how long it can store it.. In a N2 only environment it will cool without input in just a few seconds..

 

[IanC]

How does the atmosphere lose energy to space? N2 neither absorbs nor emits IR.

The N2 indefinitely holds on to its stored energy simply by staying in a gaseous phase, suspended in the gravity field. During daylight the surface inputs energy to the atmosphere, which is then returned at night.

An N₂ atmosphere can lose energy to space in case very hot molecules escape the planet's gravity. Otherwise, no. That's probably negligible.

I think you are right. Conduction warms the near-surface atmosphere during the day, and gives back during the night. Once equilibrium is established, the absorbed and returned energy need to be equal. That means, the planet's average temperature should be equal to a planet with no atmosphere, but the day / night extremes are somewhat moderated. Also, I think, convection plays a role in that the equator / pole temperature difference should be somewhat lower with, compared to without, atmosphere.

I totally disagree that average surface temperature would similar with or without an atmosphere. Radiation has a relationship to the fourth power of temperature. Twice as hot means sixteen times the output.

 

[IanC]

N2 certainly emits the energy it absorbs via collisions with other molecules...it conducts till such time as it can't, then it radiates till it reaches its equilibrium temperature...ditto for O2 and argon...

You like to claim that every thing radiates till it becomes inconvenient then N2 doesn't radiate? How quaint

At what wavelengths is the N2 radiating away this energy? I don't think it has any emission lines in IR.

 

[IanC]

How does the atmosphere lose energy to space? N2 neither absorbs nor emits IR.

The N2 indefinitely holds on to its stored energy simply by staying in a gaseous phase, suspended in the gravity field. During daylight the surface inputs energy to the atmosphere, which is then returned at night.

An N₂ atmosphere can lose energy to space in case very hot molecules escape the planet's gravity. Otherwise, no. That's probably negligible.

I think you are right. Conduction warms the near-surface atmosphere during the day, and gives back during the night. Once equilibrium is established, the absorbed and returned energy need to be equal. That means, the planet's average temperature should be equal to a planet with no atmosphere, but the day / night extremes are somewhat moderated. Also, I think, convection plays a role in that the equator / pole temperature difference should be somewhat lower with, compared to without, atmosphere.

N2 has a very low energy residency time, even lower than that of O2 and CO2. ITs the mass of these and the very narrow regions that LWIR can affect which determine the energy it can store and how long it can store it.. In a N2 only environment it will cool without input in just a few seconds..

As per usual, your post makes zero sense.

 

[CrusaderFrank]

But we agree that planet Earth without CO2 would vary from -298 degrees Fahrenheit (-183 degrees Celsius), at night, to 224 degrees Fahrenheit (106 degrees Celsius) during the day, right?

 

[IanC]

Also, I think, convection plays a role in that the equator / pole temperature difference should be somewhat lower with, compared to without, atmosphere.

Without the presence of GHGs, I am unsure that a big enough local temperature differential can build up to initiate convection, either vertically or horizontally.

 

[Olde Europe]

I totally disagree that average surface temperature would similar with or without an atmosphere. Radiation has a relationship to the fourth power of temperature. Twice as hot means sixteen times the output.

I understand your point, but I think your deliberation is incorrect. After all, incoming and outgoing radiation must be of the same size, and equal, in both systems, with, and without, atmosphere. And if with, and without, atmosphere, outgoing radiation (entirely from the surface) is the same, the average temperatures also have to be the same. No?

 

[IanC]

But we agree that planet Earth without CO2 would vary from -298 degrees Fahrenheit (-183 degrees Celsius), at night, to 224 degrees Fahrenheit (106 degrees Celsius) during the day, right?

Ahhh... I see your comment has been edited.

No, I don't agree that the Earth would be minus 300C without CO2. I doubt I would agree with any figure unless it had a huge error range.

 

[IanC]

I totally disagree that average surface temperature would similar with or without an atmosphere. Radiation has a relationship to the fourth power of temperature. Twice as hot means sixteen times the output.

I understand your point, but I think your deliberation is incorrect. After all, incoming and outgoing radiation must be of the same size, and equal, in both systems, with, and without, atmosphere. And if with, and without, atmosphere, outgoing radiation (entirely from the surface) is the same, the average temperatures also have to be the same. No?

Remember the old puzzle about having one hour to drive 30 miles? If you only go 15 miles per hour for the first half, how fast do you need to go for the second half?