Sentences with phrase «radiation from the surface does»

Not exact matches

The surface of Mars today — as seen from the myriad of robotic space missions sent to explore our next - door neighbor — appears cold and desert - like, and its whisper - thin atmosphere doesn't shield the planet from a bombardment of radiation from the Sun.

Microwaves do, make no mistake, emit radiation, and the FDA has established what it considers «safe» levels for microwaves: over the machine's «lifetime» the allowable level is «5 milliwatts of microwave radiation per square centimeter... approximately 2 inches from the oven surface.»

They don't have to be scientists to understand that the higher energy waves of visible light from the Sun can penetrate through CO2, H2O, CH4, NOZ etal in the atmosphere, but the lower energy radiation of infra - red waves, from Earth's surface, have problems getting back out through these molecules, and a new energy balance has to be established in the form of rising temperature.

Because the wavelength of emitted EM radiation varies with the temperature of the source, it does so in the form of longer - wave IR than that received from the Sun — the Earth's surface is significantly cooler than that of the Sun.

Adding CO2 does not (at least not before the climate response, which is generally stratospheric cooling and surface and tropospheric warming for increasing greenhouse gases) decrease the radiation to space in the central portion of the band because at those wavelengths, CO2 is so opaque that much or most radiation to space is coming from the stratosphere, and adding CO2 increases the heights from which radiation is able to reach space, and the stratospheric temperatures generally increase with increasing height.

Actually the judge asked a slightly incorrect question (probably unwise to correct him publicly), the question should be,» What is the molecular difference by which CO2 absorbs infrared radiation emitted from the Earth's surface but oxygen and nitrogen do not?»

What the CO2 (both «cold, hot and warm CO2 ′) and other gasses do is to make the atmosphere more optically thick to thermal IR radiation emitted (mainly) from the Earth's surface [note2] which has consequences for the equilibrium temperature profile of the atmosphere.

Although that will be true in the mid atmosphere, do you agree that is not the case near the surface of the Earth where the greenhouse molecules are being excited by blackbody radiation from the Earth's surface, but are being relaxed by collisions with other air molecules such as N2 & O2?

So even if increased infrared radiation caused by man does try to warm the surface of the oceans those processes will increase immediately and neutralise at least the majority of any extra warming from additional down welling anthropogenic infrared radiation.

But the models do not represent the earth by every square mm of land surface albedo, but by grid - scale averages — but note that the 4th power radiation from a mean albedo will almost never equal the radiation from the detailed actual surface.

Does the atmosphere absorb any significant radiation emitted from the surface?

Before you say it's the back radiation, I have to tell you that radiation from colder regions does not penetrate the warmer ocean surface more than a few nanometres.

As to the absorption of long - wave radiation from the earth's surface, while it may be true that carbon dioxide and water together do absorb certain frequency ranges of that radiation, I don't think that that matters a whole lot because most of the heat from the surface is transported to the top of the troposphere by conduction, convection and latent heat of vaporization of water during the day.

Isn't increased ice melt essentially an indication of increased energy in the whole Earth system (and assuming that it doesn't correlate with increased solar radiation or increased loss of energy away from the whole Earth system, wouldn't that be a result of increased ACO2 regardless of the trend of global surface temperatures — assuming that there is no corresponding drop in surface temperatures?)

Anyone who seen a Realclimate thread weave endlessly for weeks on end simply because the team absolutely insist that back radiation does heat the surface, even though a more careful use of words would have closed the inquiry off very quickly, may understand where I'm coming from.

Q. 2: Does this extend to the oceans and / or land surfaces and thus imply that a warmer solid or liquid surface does not absorb radiation from a cooler atmosphDoes this extend to the oceans and / or land surfaces and thus imply that a warmer solid or liquid surface does not absorb radiation from a cooler atmosphdoes not absorb radiation from a cooler atmosphere?

Briefly, the warmer body (Earth's surface) is not affected by radiation from the cooler one (the atmosphere) because that radiation does not have enough energy (high enough frequency) to bring about the conversion of its energy into thermal energy.

That greenhouse gases being absent does not effect the one third of solar radiation being absorbed by clouds Or the surface albedo can jump from 12 % to 30 % Or the greenhouse gases being absent but still have clouds to reflect radiation Or the IR (not now absorbed) by the clouds will not obey Kirchoff's Law on reaching the planet surface And so on.

How does a CO2 molecule, somewhere up in the middle troposphere, KNOW that it is only allowed to absorb upwelling radiation photons from the surface and must ignore all the other photons coming at it from all around in the atmosphere?

And in any case, heat does not flow from the cold atmosphere to the warmer surface, either by conduction, or radiation.

With 2), there's still something I don't get... and this applies just as much to your answer as to any answers you would get from climate science, since clouds are clouds (i.e droplets of water), and water vapour is a gas, so their back - radiation explanation doesn't even apply in the case of clouds (not saying it physically could apply anywhere but hopefully you get what I mean)... what I don't get is, you liken them to a blanket, but a blanket is next to you, clouds are separated from the surface by quite a bit of atmosphere — so why is it warmer the next morning at the surface when the clouds are there?

Thus CO2 does indeed warm the lower atmosphere for a hundred metres or so and that shields the CO2 above from any further surface radiation (at the CO2 spectra remember).

During the up and down cycling process potential energy is not available to the exchange of radiation in and out of the Earth system but it does become available for radiating out to space when it is returned downwards and converted back from potential energy to kinetic energy again at the surface.

To make things more exciting I'll raise the temperature of the top wall from 293.15 K to 373.15 K. Two things happen immediately, the temperature of the water vapor goes up by conduction and absorption of radiation from the top wall and so does the temperature of the surface of the water.

Now the sun would be expected to set up an undisturbed gradient from cold at the bottom to warm at the top but it does not because upward radiation from the surface plus energy drawn upwards by evaporation at the surface creates a layer 1 mm deep near the surface (the subskin) which is 0.3 C cooler than the water below it.

Most of the radiation from the surface is merely «pseudo scattered» back radiation which is not cooling the surface at all because its energy did not come from the surface.

The latter two processes transfer twice as much thermal energy to the atmosphere as does radiation from the surface according to the NASA net energy diagram reproduced in my paper.

What I do know is that the figures you mention that are magnitudes greater are (similar to problem 1) the result of the current heat content / temperature of the oceans and not of a forcing from something that changed the amount of SW radiation reaching the surface.

Anander, If the radiation changes rapidly, what you say is true, but it does not take long for the uppermost tens of meters to reach an equilibrium and in the equilibrium the heat transfer from the surface to atmosphere (and space) must equal the radiative heating.

But don't take to much notice of me as I also believe that Advection i.e. the kind of horizontal air movements that follow isobaric surfaces and therefore are predominantly horizontal) have got more of a Green House Effect (GHE) than does a radiation circuit, of say 324 W / m ² originally removed from the surface, and then returned via Green House Gases (GHGs)-- which, by the way, show no sign of having warmed at all (no hot spot) But even so, when somehow the same 324 W / m ² are delivered back to the surface for absorption it is supposed to be getting warmer.

CO2 does enhance downward radiation at the surface, but its effect at the top is to reduce upward radiation, because it radiates to space from higher generally colder layers, being more efficient as an emitter.

(2) Just saying the words «lapse rate» and «ideal gas equation» doesn't get you around having to explain how one could conserve energy if one considers the current surface temperature of the earth and imagines that one had an atmosphere transparent to IR radiation from the earth's surface.

Even if every one of my numbers is off by 10 %, and all in the same direction, I do not think it is possible to conclude that there are not hundreds of Watts / m ^ 2 of radiation coming down upon the Surface from the Atmosphere.

You agree that SOME of the downward pointing radiation comes from the low reaches of the atmosphere but I am saying ALL of the downward radiation measurable at the surface is from the low reaches (just 10's of meters) EXCEPT (minus) that which can and does go upward to space and that is called the «window» frequencies upward IR radiation.

However, the point is simply this: As long as you have an IR - absorbing atmosphere that is at a nonzero temperature, the earth's surface will have to be at a warmer temperature (in order to radiate away the energy that it receives from the sun) than it would be if the atmosphere did not absorb any of the IR radiation that the earth emits.

quote from the article: For example, in the analysis, not only does the amount of CO2 not enter in (Earth has 0.04 %, Venus a whopping 96.5 %), but the albedo (from either cloud tops or the planetary surface) does not either (Venus has dense clouds that reflect much of the incident visible radiation, while Earth does not, and Earth's surface is 70 % deep ocean, while Venus is solid crust).

Ira — regarding your summary comment 4) at May 8, 2011 at 7:51 pm my comment — NO, the atmosphere does NOT emit LWIR across a distribution of wavelengths like a blackbody, see my earlier comment at Dave in Delaware says: May 8, 2011 at 7:00 am Ira Glickstein, PhD says: «4) As I understand it, the ~ 15μm radiation from the Surface to the Atmosphere is absorbed by H2O and CO2 molecules which, when excited, bump into nitrogen and oxygen and other air molecules, and heat the air.

Otherwise, such a hypothesis does not even satisfy the First Law of Thermodynamics (basically, conservation of energy): Without substances in the atmosphere that absorb terrestrial radiation, the earth's surface at its present temperature would be emitting back out into space way more energy than it receives from the sun and hence would rapidly cool down.

Wayne If you don't like «back radiation», you could always use «plain old thermal radiation from the molecules in the atmosphere that happens to be directed back down in the general direction of the surface».......

All matter above absolute zero emits radiation and, once emitted, that radiation does not know if it is travelling from a warmer to a cooler surface or vice-versa.

I did not claim that the Atmosphere, after being excited by radiation coming up from the Surface, emits down towards the Surface and up towards Space exactly like a black body, just that it emits at a variety of wavelengths.

To do that we need to look up from ground surface to see the increase of radiation flux (W / m2).

Well that's a lot of raising to do from -40 °C especially when that radiation between the surface and the troposphere is in general a process which cools the surface.

What it does is reduce the net amount of radiation from the surface, acting like a radiation partial insulation effect.

But I don't see why that doesn't mean we can't accurately calculate the radiation emitted from the surface of the earth.

That happens partly through «new» absorption of radiation that more or less used to escape directly from the surface, as well as absorption and re-emission of radiation that used to get absorbed and re-emitted at lower layers, but now (at higher CO2) does so at higher layers.

Similarities may exist in the spectral nature of the radiation being emitted from a gas and the radiation being emitted from a differential area on a blackbody surface; but without a clearly defined surface, I don't see how Planck's blackbody radiation law can be applied.

It does not apply to the radiation moving from the colder surface to the warmer surface.

The CO2 molecules allow the shorter - wavelength rays from the Sun to enter the atmosphere and strike the Earth's surface, but they do not allow much of the long - wave radiation reradiated from the surface to escape into space.

There are many valid reasons why there could be more radiation reflected from the surface including that it originated from back radiation, this doesn't mean that it has heated the surface.