CO2 Residence Time (Soloman vs Segalstad)

[enough]

Oct 18, 2009 18:57:01 GMT radiant said:

Oct 18, 2009 17:23:12 GMT enough said:

The IR paths to space are:

1. The 10 micron IR window. (surface)

Where actually is this 10 micron IR window?

It appears it does not exist at sea level and has to be found on mountains or in antarctica

www.ipac.caltech.edu/Outreach/Edu/Windows/irwindows.html

The atmosphere itself radiates strongly in the infrared, often putting out more infrared light than the object in space being observed. This atmospheric infrared emission peaks at a wavelength of about 10 microns

The reference you found mislabeled the source of the 10 micron radiation. It is from the surface. From 10 to 15 microns, look in the ir absorption plot, there IR radiation is not absorbed by the atmosphere and radiates directly to space.


These are very rough numbers. Of the energy leaving the earths surface:

15% radiates to space (IR window)

30% is IR that is absorbed by the atmosphere (water vapor;27% and CO2;3%)

55% is basically evaporative cooling from the oceans with the energy absorbed by the atmosphere. Convection is what moves almost all this energy up thru the troposphere with the moisture carry the bulk of it.

In a desert (no moisture) the IR window dominates.

[radiant]

Oct 18, 2009 20:16:20 GMT enough said:

Oct 18, 2009 18:57:01 GMT radiant said:

Where actually is this 10 micron IR window?

It appears it does not exist at sea level and has to be found on mountains or in antarctica

www.ipac.caltech.edu/Outreach/Edu/Windows/irwindows.html

The atmosphere itself radiates strongly in the infrared, often putting out more infrared light than the object in space being observed. This atmospheric infrared emission peaks at a wavelength of about 10 microns

The reference you found mislabeled the source of the 10 micron radiation. It is from the surface. From 10 to 15 microns, look in the ir absorption plot, there IR radiation is not absorbed by the atmosphere and radiates directly to space.


These are very rough numbers. Of the energy leaving the earths surface:

15% radiates to space (IR window)

30% is IR that is absorbed by the atmosphere (water vapor and CO2)

55% is basically evaporative cooling from the oceans with the energy absorbed by the atmosphere. Convection is what moves almost all this energy up thru the troposphere with the moisture carry the bulk of it.

In a desert (no moisture) the IR window dominates.

There is significant moisture in a desert. The dryest place on earth is Ridge 'A' in antartica with a minimum of only 0.25mm of precipital water vapour, One of the next driest places is the south pole with a minimum of about .70mm of water vapour, but even so water vapour still dominates the downdwelling ir radiation.

The IR window may be a fallacy created by a misunderstanding of the nature of absorption or it only applies to mountain top observatories or Antarctica.

Generally spectra are constructed to make it appear as if there is no absorption and evidently people dont realise from these graphs the tremendous ability of water to absorb IR radiation

[socold]

Oct 18, 2009 15:56:04 GMT icefisher said:

I am not proposing anything Socold. The CO2 effect may already be completely saturated as far as surface temperatures are concerned. If they are not, its very unlikely that 3.7 watts will actually get applied to surface temperatures instead of getting bled off either entirely or to some extent to other IR frequencies through partial the opaqueness and conduction to other gasses in the atmosphere.

The 3.7wm-2 reduction in outgoing energy if co2 is doubled and everything else remains the same is solid. The figure is not open to such uncertainty to make any significant difference.

So everything else cannot stay the same. Everything else has to change so that the Earth has double co2 but without a 3.7wm-2 imbalance.

As for response you say: "its very unlikely that 3.7 watts will actually get applied to surface temperatures instead of getting bled off either entirely or to some extent to other IR frequencies through partial the opaqueness and conduction to other gasses in the atmosphere"

This is ludicrous. You've just made a conclusion at a complete whim.

You don't have any calculations to back this up because the only available calculations are from models, which oppose what you claim here and you dismiss models anyway.

So how on earth can you conclude "its very unlikely that 3.7 watts will actually get applied to surface temperatures"?

And if there is a need one should note that there is a huge shift in day to day ground emission rates far and away beyond 3.7watts you are rambling on about convection rates we see exceeding that every day.

Would you argue in similar fashion that the last glacial period was insignificant because global temperature was just 5-6C lower than today and daily temperature fluctuations are much larger than that?

The 3.7wm-2 reduction is an average over an entire year which is very significant irregardless of daily fluctuations.

[socold]

Oct 18, 2009 15:58:20 GMT trbixler said:

In a vacuum the calculations will match. There is no question about the forces involved. The experiments can and have been done. Ballistic galvanometers and all. The cannon ball tends to make the friction small but the vacuum takes it to zero. There are not equivalent experiments to get to the 3.7 number.

My point is that you don't need to do the experiment in that specific case. You can calculate it from physics.

Just as it's possible to calculate the reduction in energy emitted into space if there was twice as much co2 in the atmosphere.

All you need to do is calculate the transmission of IR through the atmosphere, integrating over the entire atmosphere, including the pressure, temperature, concentration of gases, etc at various heights.

Knowing the absorption properties of gases and knowing the atmospheric profile is enough to calculate this.

You don't need to actually double co2 in some kind implausible experiment. Frankly the suggestion that science can never figure out the reduction in IR if there was twice as much co2 in an atmosphere exactly the same as present smacks of a kind of anti-scientific "giving up" when its a perfectly solvable problem.

[socold]

Oct 18, 2009 17:23:12 GMT enough said:

Oct 18, 2009 12:21:23 GMT socold said:

Oct 18, 2009 11:59:27 GMT nautonnier said:

Socold: "The GCMs show the planet

I won't find this because I am not running any calculation. The models do and they don't find this. Whether any heat is transported by the hydrological cycle to the tropopause is a quesiton in itself. Also radiation from Earth into space crosses the tropopause but isn't from the tropopause.

Clueless


The IR paths to space are:

1. The 10 micron IR window. (surface)
2. Mosture in the lower troposphere (5km)
3. The cloud tops. (>5KM)
4. CO2 at the stratopause (50 KM)

Heat flow in the troposphere is dominated by convection

That list is incomplete but reinforces my point that energy emitted into space is not from the tropopause.

[socold]

Oct 18, 2009 18:20:27 GMT jimcripwell said:

socold writes "The IPCC give radiative forcing from doubling co2 to be about 3.7wm-2"

Sometimes I despair. The discussion over the last few days has established :-

1. The 3.7 wm-2 is estimated using radiative transfer models.

2. Radiative transfer models deal with real situations in the atmosphere.

3. The definition of radiative forcing in IPCC TAR Chapter 6 is a purely hypothetical sitution.

4. I can see no logic that explains why radiative transfer models, which deal with real situations, can estimate radiative forcing, which is based on a hypothetical situation. However, I can be wrong.

So 5. Where is the reference that proves that radiative transfer models can estimate a value for radiative forcing, as defined by the IPCC in Chapter 6 of the TAR?

I wonder how many more times I need to ask this question, before someone actually addresses it and gives me an answer. I suspect the reference does not exist.

The radiative transfer models are used to derive a hypothetical situation - a doubling of co2 in the atmosphere with everything else remaining the same. The result from that calculation is an outgoing IR reduction of about 3.7wm-2.

"Where is the reference that proves that radiative transfer models can estimate a value for radiative forcing"

They do estimate a value for radiative forcing, so the question isn't can they, but do they do it correctly.

[radiant]

If C02 was significantly emitting radiation back to earth why cant you see this from places with low water vapour like antarctica?

Even with extraordinaryly low levels of water vapour in the entire atmosphere above the detectors water emissions are the ones that are detected

[enough]

Oct 18, 2009 20:45:09 GMT socold said:

Oct 18, 2009 17:23:12 GMT enough said:

Oct 18, 2009 12:21:23 GMT socold said:

Clueless


The IR paths to space are:

1. The 10 micron IR window. (surface)
2. Mosture in the lower troposphere (5km)
3. The cloud tops. (>5KM)
4. CO2 at the stratopause (50 KM)

Heat flow in the troposphere is dominated by convection

That list is incomplete but reinforces my point that energy emitted into space is not from the tropopause.

So complete the list in order of magnitude.

[jimcripwell]

socold writes "The radiative transfer models are used to derive a hypothetical situation - a doubling of co2 in the atmosphere with everything else remaining the same."

IPCC Definition of Forcing:

"The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is the change in net (down minus up) irradiance (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values.

Can you explain to me how radiative transfer models can accomodate both "AFTER allowing for stratospheric temperatures to readjust to radiative equilibrium," and " but with surface and tropospheric temperatures and state held fixed at the unperturbed values."

I am afraid my knowledge of radiaitve transfer models is not by any means complete, but this I find difficult to understand.

[enough]

Oct 18, 2009 21:52:59 GMT jimcripwell said:

socold writes "The radiative transfer models are used to derive a hypothetical situation - a doubling of co2 in the atmosphere with everything else remaining the same."

IPCC Definition of Forcing:

"The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is the change in net (down minus up) irradiance (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values.
.

Jim

Where did this come from? There has gotten to be some much BS in this thread that I have not read every thing.

I will explain why afer I see the source and context

Thanks

[jimcripwell]

enough writes "Where did this come from?"

nautonnier posted this

Re: CO2 Residence Time (Soloman vs Segalstad)
« Reply #229 on Oct 11, 2009, 5:14am »

So far as I am aware this is the definition used by the IPCC in Chapter 6 of the TAR to WG1. I will hunt a little more and see if I can confirm this.

[nautonnier]

Oct 18, 2009 20:35:01 GMT socold said:

Oct 18, 2009 15:56:04 GMT icefisher said:

I am not proposing anything Socold. The CO2 effect may already be completely saturated as far as surface temperatures are concerned. If they are not, its very unlikely that 3.7 watts will actually get applied to surface temperatures instead of getting bled off either entirely or to some extent to other IR frequencies through partial the opaqueness and conduction to other gasses in the atmosphere.

The 3.7wm-2 reduction in outgoing energy if co2 is doubled and everything else remains the same is solid. The figure is not open to such uncertainty to make any significant difference.

So everything else cannot stay the same. Everything else has to change so that the Earth has double co2 but without a 3.7wm-2 imbalance.

As for response you say: "its very unlikely that 3.7 watts will actually get applied to surface temperatures instead of getting bled off either entirely or to some extent to other IR frequencies through partial the opaqueness and conduction to other gasses in the atmosphere"

This is ludicrous. You've just made a conclusion at a complete whim.

You don't have any calculations to back this up because the only available calculations are from models, which oppose what you claim here and you dismiss models anyway.

So how on earth can you conclude "its very unlikely that 3.7 watts will actually get applied to surface temperatures"?

And if there is a need one should note that there is a huge shift in day to day ground emission rates far and away beyond 3.7watts you are rambling on about convection rates we see exceeding that every day.

Would you argue in similar fashion that the last glacial period was insignificant because global temperature was just 5-6C lower than today and daily temperature fluctuations are much larger than that?

The 3.7wm-2 reduction is an average over an entire year which is very significant irregardless of daily fluctuations.

SoCold - are you an automaton?

We clarify that you are unaware of the workings of GCM and do not know the power of the climate to carry energy to the tropopause by other means other than radiation.

Yet after only a short pause there you are parroting the 3.7WM^-2 mantra again as if you knew what effect it might have - when you have admitted that you don't know.

A small change in the hydrologic cycle and convection would easily transport the heat that you are concerned about to the tropopause past any real concentrations of CO₂ and other GHG and raise albedo reducing the input energy.

[jimcripwell]

enough. Here is the complete IPCC discussion of the definition of radiative forcing in Chapter 6 of the TAR to WG1.

6.1.1 Definition
The term "radiative forcing" has been employed in the IPCC Assessments to denote an externally imposed perturbation in the radiative energy budget of the Earth's climate system. Such a perturbation can be brought about by secular changes in the concentrations of radiatively active species (e.g., CO2, aerosols), changes in the solar irradiance incident upon the planet, or other changes that affect the radiative energy absorbed by the surface (e.g., changes in surface reflection properties). This imbalance in the radiation budget has the potential to lead to changes in climate parameters and thus result in a new equilibrium state of the climate system. In particular, IPCC (1990, 1992, 1994) and the Second Assessment Report (IPCC, 1996) (hereafter SAR) used the following definition for the radiative forcing of the climate system: "The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is the change in net (down minus up) irradiance (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropo-spheric temperatures and state held fixed at the unperturbed values". In the context of climate change, the term forcing is restricted to changes in the radiation balance of the surface-troposphere system imposed by external factors, with no changes in stratospheric dynamics, without any surface and tropospheric feedbacks in operation (i.e., no secondary effects induced because of changes in tropospheric motions or its thermodynamic state), and with no dynamically-induced changes in the amount and distribution of atmospheric water (vapour, liquid, and solid forms). Note that one potential forcing type, the second indirect effect of aerosols (Chapter 5 and Section 6.8), comprises microphysically-induced changes in the water substance. The IPCC usage of the "global mean" forcing refers to the globally and annually averaged estimate of the forcing.

[nautonnier]

Oct 18, 2009 23:02:37 GMT enough said:

Oct 18, 2009 21:52:59 GMT jimcripwell said:

socold writes "The radiative transfer models are used to derive a hypothetical situation - a doubling of co2 in the atmosphere with everything else remaining the same."

IPCC Definition of Forcing:

"The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is the change in net (down minus up) irradiance (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values.
.

Jim

Where did this come from? There has gotten to be some much BS in this thread that I have not read every thing.

I will explain why afer I see the source and context

Thanks

It comes from the AR4 Working Group report AR4-wg1-chapter2 section 2.2 "concept of radiative forcing" first paragraph and is a reference out to a previous paper.

You will find the same definition worded slightly differently in :

www.epa.gov/climatechange/glossary.html#R

Where it is accepts the problems with the hydrologic cycle and aerosols:

"Radiative Forcing
Radiative forcing is the change in the net vertical irradiance (expressed in Watts per square metre: Wm-2) at the tropopause due to an internal change or a change in the external forcing of the climate system, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun. Usually radiative forcing is computed after allowing for stratospheric temperatures to readjust to radiative equilibrium, but with all tropospheric properties held fixed at their unperturbed values. Radiative forcing is called instantaneous if no change in stratospheric temperature is accounted for. Practical problems with this definition, in particular with respect to radiative forcing associated with changes, by aerosols, of the precipitation formation by clouds, are discussed in Chapter 6 of the IPCC Third Assessment Report Working Group I: The Scientific Basis."

Hope that helps

[enough]

Oct 19, 2009 0:58:07 GMT nautonnier said:

Oct 18, 2009 23:02:37 GMT enough said:

Jim

Where did this come from? There has gotten to be some much BS in this thread that I have not read every thing.

I will explain why afer I see the source and context

Thanks

It comes from the AR4 Working Group report AR4-wg1-chapter2 section 2.2 "concept of radiative forcing" first paragraph and is a reference out to a previous paper.

You will find the same definition worded slightly differently in :

www.epa.gov/climatechange/glossary.html#R

Where it is accepts the problems with the hydrologic cycle and aerosols:

"Radiative Forcing
Radiative forcing is the change in the net vertical irradiance (expressed in Watts per square metre: Wm-2) at the tropopause due to an internal change or a change in the external forcing of the climate system, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun. Usually radiative forcing is computed after allowing for stratospheric temperatures to readjust to radiative equilibrium, but with all tropospheric properties held fixed at their unperturbed values. Radiative forcing is called instantaneous if no change in stratospheric temperature is accounted for. Practical problems with this definition, in particular with respect to radiative forcing associated with changes, by aerosols, of the precipitation formation by clouds, are discussed in Chapter 6 of the IPCC Third Assessment Report Working Group I: The Scientific Basis."

Hope that helps

Nautonnier, Jim

It is going to take a bit to let this sink in. I have been concentrating on studing what I consider unbiased works by Goody. My first reponse to seeing this is that they have left out a major portion of what drives the earths temperature. When CO2 doubles, radiation to space from the Stratopause (co2) will also double. This is what causes the stratopause to cool a bit.

Thanks, be back in a few days.

Do not let the background noise on this thread get out of hand.