Sentences with phrase «in radiative absorption»

Oxidation of methane to CO2, which requires reactions with the OH radical, produces an instantaneous reduction in radiative absorption and emission since CO2 is a weaker greenhouse gas than methane, although CO2 has a longer lifetime.

Not exact matches

The recent JCAP paper published in Nature Communications introduces a transcendent approach to understanding PEC device performance for arbitrary material and device quality, using five representative parameters: semiconductor absorption fraction, external radiative efficiency, series resistance, shunt resistance and catalytic exchange current density to account for imperfect light absorption, charge transport and catalysis.

The magnitude of the radiative forcing per doubling is equal to the effect of band widenning, which is (BW1 + BW2) * depth of valley or height of hill, plus some additional effect in the center of the band, which is on the order of 1/2 * (BW1 + BW2) * increase in height or depth of hill or valley; the central contribution could be more or less than that, but it will be less than double (because the shape of the absorption spectrum won't allow a square shape in the graph of the spectral flux).

The effect is a continuum of different absorption spectra that all have the same band - widenning per doubling and same effects at the center at various stages between no effect and saturation, though they are at different stages in that process for any given amount of CO2; the radiative forcing is a weighted average of the effects of each of those absorption spectra; once the center of the band is saturated for all of the spectra, the band widenning effect is the same for each and thus the forcing from the band widenning is the same as it is in the original simplified picture.

In the tugging on the temperature profile (by net radiant heating / cooling resulting from radiative disequilibrium at single wavelengths) by the absorption (and emission) by different bands, the larger - scale aspects of the temperature profile will tend to be shaped more by the bands with moderate amounts of absorption, while finer - scale variations will be more influenced by bands with larger optical thicknesses per unit distance (where there can be significant emission and absorption by a thinner layer).

But if the optical thickness in that band is sufficiently smaller than in another band (depending on wavelengths), adding some absorption to the optically - thinner band would tend to result in warming of the colder layers (as there would be less temperature variation over height in radiative equilbrium for that band, given the same surface (+ tropospheric) temperatures.

Re my 441 — competing bands — To clarify, the absorption of each band adds to a warming effect of the surface + troposphere; given those temperatures, there are different equilibrium profiles of the stratosphere (and different radiative heating and cooling rates in the troposphere, etc.) for different amounts of absorption at different wavelengths; the bands with absorption «pull» on the temperature profile toward their equilibria; disequilibrium at individual bands is balanced over the whole spectrum (with zero net LW cooling, or net LW cooling that balances convective and solar heating).

On the other hand, water vapor and CO2 have many strong radiative absorption transitions in the infrared (as do also ozone, CH4, N2O, and a variety of CFCs).

In an atmosphere open to the sky as opposed to a container in a laboratory a density change is forced by the absorption of radiative energy by the GHG moleculeIn an atmosphere open to the sky as opposed to a container in a laboratory a density change is forced by the absorption of radiative energy by the GHG moleculein a laboratory a density change is forced by the absorption of radiative energy by the GHG molecules.

However the radiative absorption capability of CO2 is also high so in practice it has little difficulty acquiring the energy needed to initiate uplift.

Absorption in the atmosphere of solar radiation by CO2 doesn't buy you any reduction in the radiative forcing which is conventionally applied to the whole atmosphere and surface.

If, for instance, CO2 concentrations are doubled, then the absorption would increase by 4 W / m2, but once the water vapor and clouds react, the absorption increases by almost 20 W / m2 — demonstrating that (in the GISS climate model, at least) the «feedbacks» are amplifying the effects of the initial radiative forcing from CO2 alone.

Your hypothesis assumes that increased absorption of energy in the troposphere will be transmitted to the surface by convection, since radiative transfer doesn't change if the temperature remains constant, and the radiative imbalance at the TOA wouldn't change.

Aerosol particles infl uence radiative forcing directly through refl ection and absorption of solar and infrared radiation in the atmosphere.

If that is the case and if the continuum is coming in from all directions, then there is no net radiative power transfer going on and in fact, one would not observe any absorption spectra (or emission spectra) at all.

«Because the solar - thermal energy balance of Earth [at the top of the atmosphere (TOA)-RSB- is maintained by radiative processes only, and because all the global net advective energy transports must equal zero, it follows that the global average surface temperature must be determined in full by the radiative fluxes arising from the patterns of temperature and absorption of radiation.»

depending on what I'm doing, I can do straight attenuation or do radiative transfer where there is both absorption and emission in a layer.

Would it have been so difficult to terminate the smaller atmospheric absorption arrow in the atmosphere itself and then have a separate set of arrows (both toward the surface and into space) showing the radiative energy from the atmosphere?

Vis.: www.garfield.library.upenn.edu/classics1981/A1981LQ21800001.pdf Even more to the point, he goes on to state that [quote] «The regions of validity of the linear, square root, and nonoverlapping approximations were considered in this article...» [endquote] and notes that the summary of the [quote] «various models and approximations for band absorption» [endquote] given in that article had apparently been useful in many later studies requiring [quote] «mathematical calculation» [endquote] of the radiative exchange by infrared bands.

The radiative energy inciding on our skin is absorbed by the molecules of water in our bodies by Resonance Absorption.

They assume a basis for all this, the radiative heat absorption by CO2 (this is in their founding documents), and produce massive summaries, generally including long term ordinary linear regression in approriately applied to a time series, and then make a statement such as «an increase of.2 deg C / decade».

Pekka, to claim that the temperature effect of CO2 absorbing IR in the atmosphere is unmeasurable except in the atmosphere is a good way of glossing over the fact that the claimed warming phenomenon (backradiation or insulation or IR absorption) is: a. imprecisely described, and non-existent according to G&T b. untested in the laboratory — probably because it hasn't been precisely described c. very small according to the precisely measured radiative transfer data precisely modeled in Spectralcalc d. confounded by other variables in the real atmosphere

We need to examine the Gas Laws in some detail to consider how the radiative absorption capabilities of Greenhouse Gases could be dealt with given that the Gas Laws have no term for the radiative capabilities of molecules.

In any case, yes, radiative effects should be accounted for with a first - principles radiative model, that is to say, insolation + absorption (I don't think this is hard to do).

The direct radiative effects of aerosols can be divided in reflection and absorption.

This study seeks to explain the effects of cloud on changes in atmospheric radiative absorption that largely balance changes in global mean precipitation under climate change.

And, there is plenty of empirical data at every level: There is empirical data on the basic absorption lines of the various atmospheric constituents, there is a wealth of empirical data backing up the basic equations of radiative transfer that are applied in calculating the greenhouse effect in just the same way that engineers and scientists use these equations everyday in other calculations, there is empirical spectra looking both up from the surface of the earth and down from satellites.

In the absence of absorption of terrestrial radiation by the atmosphere (and with the other caveats about still having the same albedo and such), that average temperature would have to be 255 K at the surface because of radiative balance and then the temperature would decrease with height at the lapse rate from there.

jae says: «You are making the usual EXTREMELY big jump in saying that because there is absorption / emission by GHGs that there is a radiative GHE.»

If I were choosing a model to describe with as much quantitative fidelity as possible the greenhouse effect in the earth's atmosphere, then the model I would choose would be a state - of - the - art convective - radiative transfer code using the actual composition and empirical absorption / emission lines for the atmospheric constituents.

You are making the usual EXTREMELY big jump in saying that because there is absorption / emission by GHGs that there is a radiative GHE.

Relative integrated IR absorption in the atmospheric window is not the same as relative radiative efficiency

1950s: Research on military applications of radar and infrared radiation promotes advances in radiative transfer theory and measurements = > Radiation math — Studies conducted largely for military applications give accurate values of infrared absorption by gases = > CO2 greenhouse — Nuclear physicists and chemists develop Carbon - 14 analysis, useful for dating ancient climate changes = > Carbon dates, for detecting carbon from fossil fuels in the atmosphere, and for measuring the rate of ocean turnover = > CO2 greenhouse — Development of digital computers affects many fields including the calculation of radiation transfer in the atmosphere = > Radiation math, and makes it possible to model weather processes = > Models (GCMs)-- Geological studies of polar wandering help provoke Ewing - Donn model of ice ages = > Simple models — Improvements in infrared instrumentation (mainly for industrial processes) allow very precise measurements of atmospheric CO2 = > CO2 greenhouse.

The solar shortwave absorption is by far the largest uncertainty in modeling the global radiative budget.