Although CO2 absorbs thermal radiation from the Earth, it emits more. Carbon dioxide is in thermal deficit in terms of radiative balance. Nitrogen and oxygen constantly feed CO2 with heat so that it maintains a temperature higher than its radiative equilibrium. CO2 is a coolant.
> CO2 is a coolant. Location matters Rog. Again CO2 only, which ignores wv’s significant contribution to backradiation at the surface. A hyper accurate value isn’t required to make the point you can’t simply ignore energy fluxes which don’t fit the pressure-diddit model.
> You can keep all your radiative magnitudes Not if I pull all of the LW emitters out of the atmosphere, Rog. This is where your “CO2 radiates according to its temperature” argument breaks down — not because it’s incorrect, but because of what it leaves out.
> You’ve lost me there. Retrace the steps. 1) Sun heats ground. 2) Ground heats atmosphere. 3) LW emitters do so as a function of their temperature. You should only need a crayon and some paper to do the rest of the math here.
Ah, I see you’ve been bamboozled by Kevin Trenberth. The radiatively active molecules in the atmosphere radiate according to the temperature they are given by pressurised N2 and O2 in all directions, not just up and down. Here, I’ve fixed the diagram for you:
You’re talking about radiation-thermalised N2 and O2 being forced downwards by air pressure generated by the helicopter blades.. What has this to do with your direction-selective measurements of radiation from the surface being absorbed and re-emitted in all directions by air?
There’s nothing ‘ad hoc’ about the computational proof on the right of the diagram. Check the figures for yourself. Maybe you need to understand the Bernoulli equation a bit better as well as the ideal gas law. http://hyperphysics.phy-astr.gsu.edu/hbase/press.html …
> computational proof I love it when you guys come up with fancier and fancier ways to say “model”. So painted into a corner it isn’t funny … because sadly it seems to be working. Again for the left side of the curve, here’s 333 W/m2 downwelling LW, *observed*. Deal with it.
As I said, no problem with your radiation magnitudes. The problem is you seem to think these measurements tell you something about cause and effect. They don’t. My calcs aren’t a model, they are just quantities which confirm the ideal gas law., and the standard atmosphere.
You missed a step between 2 and 3. CO2 is thermalised in collisions with N2 and O2 and raised from its radiative equilibrium temperature of -77.8C to 15C in the 1 bar pressurised near surface environment. See Kirchoff and Bernoulli, and then report back.
> collisions with warm N2 and O2 Which was heated by what, Rog. And how does this goose chase lead us to conclude that CO2 suddenly does not emit according to its temperature as you had promised us earlier? How does “mean free path” negate 333 W/m2 of downwelling LW?
You’ve asked three questions, so I’ll answer with three tweets, as I know you only reply to one thing in a tweet. In reverse order: 3) Mean free path means ‘downwelling’ LW doesn’t get directly from cloud base to surface as Trenberth’s misleading cartoon implies. [Tweet 1 of 3]
2) CO2 does radiate according to the temperature it is kept at by warm N2 and O2, despite trying to cool to it’s radiative equilibrium temperature of -77.8C, and this elevated temperature is what we’re measuring CO2 radiating at. [Tweet 2 of 3]
1) N2 and O2 are at the temperature they’re at, because the energy density of the troposphere is what it is, because energy=pressure*volume (and is proportional to insolation), in accordance with Bernoulli’s equation. [Tweet 3 of 3]
doesn’t get directly from cloud base to surface
Oh for shite’s sake, Roger it’s a schematic. Are we supposed to draw every fucking atom in the atmosphere before you’ll rent a clue.
Well at a bare minimum, I’d expect you to acknowledge that the chain of CO2 molecules doing the absorbing and re-emitting are only emitting according to the elevated temperature they are kept at by collisions with warm N2 and O2, in turn kept warm by energy=pressure*volume (+Sun)
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October 8, 2018 at 08:27AM