Does the earth behave like a black body for infrared radiation?
It seems to me the author is relying on this assumption without mentioning it. Probably being right and just for the sake of simplicity, but it’s quite an important assumption just to let it not mentioned. It could also be that I am not understanding well enough. I’m not really walking on very solid ground.
In my own simplified mental framework climate change consists in the earth changing it’s emitivity/absorption coefficient (function of wavelength) alone. All the atmospheric phenomena, radiation trapped mid-way before escaping, etc would be transparent for the observer outside of the earth. Just inner behaviors that would be accounted for by this emission/absorption function changes. Precisely the emission/absorption function that the author of this article is not mentioning, or more precisely only mentioning for the absorption side. I’ve never really discussed it with other more serious physicists.
Well, I think I've an answer to myself. The author says that the atmosphere absorbs like 90% of the IR radiation emitted by the surface so, in what concerns IR, I guess it is close enough to a black body. So yes, the earth from outside would be seen as a black body for IR.
Thanks Ugo. This is well described for photons, but does not analyze solar-emitted energetic protons and their current flows through our fair planet, largely through the poles.
John, excuse me, but there is no such a thing as "CO2-only" climate models. All climate models are multi-parametric, even simple ones, and, in particular, take into account the effect of water vapor. Unfortunately, the discussion has gone a little astray, even in our "holobionts" group. But we need to avoid oversimplifications such as those we read in the comments, even sent by people who should have known better.
My apologies for writing "CO2 only climate models", when I meant the models which ignore the earth-heating effects and the effects of moving water over and through the land, such as the Biotic Pump model.
You nudged me to find some papers about the "Telluric currents" induced in the earth by "Solar Wind", and here is one from last year, which serves:
The current studies of solar-terrestrial relations and possible impact of space weather on the seismic activity are based on statistical analysis without detailed consideration of possible physical mechanism that results in fuzzy and contradictory conclusions. We propose to consider a hypothesis of electromagnetic earthquake triggering by a sharp rise of telluric currents in lithosphere including crust faults due to interaction of solar flare X-ray radiation with ionosphere-atmosphere-lithosphere system resulted in a rise of telluric currents in the crust faults. This hypothesis is based on field and laboratory experiments carried out in Russia within the last forty years and clearly demonstrated a possibility of earthquake triggering by electric current injected into the fault. We developed a mathematical model and computer code for numerical estimations of telluric currents generated by solar flare radiations. The obtained numerical results demonstrate that solar flares can cause variations in the density of telluric currents in the crust faults, comparable to the current densities generated in the Earth’s crust by artificial pulsed power sources capable to trigger earthquakes. Consequently, the triggering of seismic events is possible not only by artificial sources of electric current, but also by ionospheric disturbances caused by strong solar flares.
Cool!
Engineers are always the best!
Does the earth behave like a black body for infrared radiation?
It seems to me the author is relying on this assumption without mentioning it. Probably being right and just for the sake of simplicity, but it’s quite an important assumption just to let it not mentioned. It could also be that I am not understanding well enough. I’m not really walking on very solid ground.
In my own simplified mental framework climate change consists in the earth changing it’s emitivity/absorption coefficient (function of wavelength) alone. All the atmospheric phenomena, radiation trapped mid-way before escaping, etc would be transparent for the observer outside of the earth. Just inner behaviors that would be accounted for by this emission/absorption function changes. Precisely the emission/absorption function that the author of this article is not mentioning, or more precisely only mentioning for the absorption side. I’ve never really discussed it with other more serious physicists.
Any comments?
Well, I think I've an answer to myself. The author says that the atmosphere absorbs like 90% of the IR radiation emitted by the surface so, in what concerns IR, I guess it is close enough to a black body. So yes, the earth from outside would be seen as a black body for IR.
I am writing a complete description of this subject. Stay tuned!
Thanks Ugo. This is well described for photons, but does not analyze solar-emitted energetic protons and their current flows through our fair planet, largely through the poles.
Well, it would be nice if there were data on these possible effects. Do you have references to studies in this field?
No, I don't have references, but the flows exist and are studied by NASA and others.
It's an interesting topic, but I can't cone down on all the interesting topics.
Like the CO2-only climate models, I'm not sure how it came to be excluded from consideration by "the community".
John, excuse me, but there is no such a thing as "CO2-only" climate models. All climate models are multi-parametric, even simple ones, and, in particular, take into account the effect of water vapor. Unfortunately, the discussion has gone a little astray, even in our "holobionts" group. But we need to avoid oversimplifications such as those we read in the comments, even sent by people who should have known better.
My apologies for writing "CO2 only climate models", when I meant the models which ignore the earth-heating effects and the effects of moving water over and through the land, such as the Biotic Pump model.
You nudged me to find some papers about the "Telluric currents" induced in the earth by "Solar Wind", and here is one from last year, which serves:
Telluric Currents Generated by Solar Flare Radiation: Physical Model and Numerical Estimations https://www.mdpi.com/2073-4433/14/3/458
The current studies of solar-terrestrial relations and possible impact of space weather on the seismic activity are based on statistical analysis without detailed consideration of possible physical mechanism that results in fuzzy and contradictory conclusions. We propose to consider a hypothesis of electromagnetic earthquake triggering by a sharp rise of telluric currents in lithosphere including crust faults due to interaction of solar flare X-ray radiation with ionosphere-atmosphere-lithosphere system resulted in a rise of telluric currents in the crust faults. This hypothesis is based on field and laboratory experiments carried out in Russia within the last forty years and clearly demonstrated a possibility of earthquake triggering by electric current injected into the fault. We developed a mathematical model and computer code for numerical estimations of telluric currents generated by solar flare radiations. The obtained numerical results demonstrate that solar flares can cause variations in the density of telluric currents in the crust faults, comparable to the current densities generated in the Earth’s crust by artificial pulsed power sources capable to trigger earthquakes. Consequently, the triggering of seismic events is possible not only by artificial sources of electric current, but also by ionospheric disturbances caused by strong solar flares.