Sentences with phrase «different radiative forcing»

I will explore the potential for distinguishing among different radiative forcing scenarios via their impact on regional climate changes, illustrated by a particular case study.

In the case of the CMIP5 models, Weaver et al. (2012) showed that the behavior of the AMOC was similar over the 21st century under four very different radiative forcing scenarios (RCP 2.6; RCP4.5; RCP 6.0; RCP8.5 — these Representative Concentration Pathways [RCPs] are detailed in Moss et al., 2010).

Each greenhouse gas has a different radiative forcing formula, but the most important is that of CO2:

All natural variation is now occurring on a different radiative forcing path.

This model took into account the different atmospheric lifetimes of different greenhouse gases and the different radiative forcings of each gas, and also considered delays in the climate system caused primarily by the thermal inertia of the ocean.

Not exact matches

A study released last month in the Journal of Geophysical Research: Atmospheres used three different models to run the same SSCE scenario in which sea - salt engineering was used in the low - latitude oceans to keep top - of - atmosphere radiative forcing at the 2020 level for 50 years and was then abruptly turned off for 20 years.

(C) potential metrics and approaches for quantifying the climatic effects of black carbon emissions, including its radiative forcing and warming effects, that may be used to compare the climate benefits of different mitigation strategies, including an assessment of the uncertainty in such metrics and approaches; and

, there is a lot of interesting stuff going on in Antarctica: the complexities of different forcings (ozone in particular), the importance of dynamical as well as radiative processes, and the difficulties of dealing with very inhomogeneous and insufficiently long data series.

They, too, assume an equivalence in radiative forcing between GHG and aerosol, What they do is add different estimates of the aerosol radiative forcing to the GHG forcing, while keeping the temperature response fixed at the observed recent warming.

[Response: There's some good thinking here, but I think you may have confused Gavin's discussion of the attempts by Andrae et al to infer climate sensitivity from recent warming with the question of whether there's a different sensitivity coefficient for aerosol vs GHG radiative forcing.

For example, we know the past CO2 radiative forcing to very high accuracy, but there are more uncertainties in the aerosol forcing; applying a consistent climate sensitivity to both CO2 and aerosols, you can get a match to the observed record for a range of different supposed aerosol forcings, but you can't take it too far.

The LGM was a very different world than the present, involving considerable expansions of sea ice, massive Northern Hemisphere land ice sheets, geographically inhomogeneous dust radiative forcing, and a different ocean circulation.

These phenomena — sun spots, a slightly different earth orbit, a decrease in volcanic activity — intermittently warmed the region through increased radiative forcing, and recently have been joined by a new force: greenhouse gases.

Could the climate forcing itself, such as increasing GHGs, affect parameterizations independently of the larger scale climate changes (for example, by changing thermal damping of various kinds of waves, or by changing the differences of radiative effects between different amounts and kinds of clouds)?

However, there is a good reason for this, and that is observation that different forcings that have equal «radiative» impacts have very similar responses.

I realise that the AR5 radiative forcing graph shows different emitted compounds, but you seem to suggest that these emissions lead to a CO2 rise in the atmosphere.

[Response: It's probably also worth noting that the standard radiative forcing is a diagnostic of what is going on designed so that different forcing mechanisms can be usefully compared.

The different scenarios have net radiative forcing in 2010 (with respect to 1984) of 1.6 W / m2, 1.2 W / m2 and 0.5 W / m2 — compared to ~ 1.1 W / m2 in the observed forcing since then.

We should underscore that the concepts of radiative forcing and climate sensitivity are simply an empirical shorthand that climatologists find useful for estimating how different changes to the planet's radiative balance will lead to eventual temperature changes.

The main changes in radiative forcing from the precessional cycle are in the latitudinal and seasonal distribution, not in the global mean, which is why the nature of the response can be expected to be different from doubling CO2.

Different climates have different vertical temperature profiles (aside from horizontal and temporal temperature variations), which affects the radiative forcing that an amount and arrangement of greenhouse agents (CO2, CH4, etc, also, water vapor and clouds) wDifferent climates have different vertical temperature profiles (aside from horizontal and temporal temperature variations), which affects the radiative forcing that an amount and arrangement of greenhouse agents (CO2, CH4, etc, also, water vapor and clouds) wdifferent vertical temperature profiles (aside from horizontal and temporal temperature variations), which affects the radiative forcing that an amount and arrangement of greenhouse agents (CO2, CH4, etc, also, water vapor and clouds) will have.

, there is a lot of interesting stuff going on in Antarctica: the complexities of different forcings (ozone in particular), the importance of dynamical as well as radiative processes, and the difficulties of dealing with very inhomogeneous and insufficiently long data series.

[Response: There's some good thinking here, but I think you may have confused Gavin's discussion of the attempts by Andrae et al to infer climate sensitivity from recent warming with the question of whether there's a different sensitivity coefficient for aerosol vs GHG radiative forcing.

[Response # 2: The standard for comparing responses across different models is to look at the radiative forcing at the top of the atmosphere — for 2xCO2 it is around 4 W / m2 (read the new National Academies report on this for a much more detailed discussion of the concept).

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.

They, too, assume an equivalence in radiative forcing between GHG and aerosol, What they do is add different estimates of the aerosol radiative forcing to the GHG forcing, while keeping the temperature response fixed at the observed recent warming.

First, for changing just CO2 forcing (or CH4, etc, or for a non-GHE forcing, such as a change in incident solar radiation, volcanic aerosols, etc.), there will be other GHE radiative «forcings» (feedbacks, though in the context of measuring their radiative effect, they can be described as having radiative forcings of x W / m2 per change in surface T), such as water vapor feedback, LW cloud feedback, and also, because GHE depends on the vertical temperature distribution, the lapse rate feedback (this generally refers to the tropospheric lapse rate, though changes in the position of the tropopause and changes in the stratospheric temperature could also be considered lapse - rate feedbacks for forcing at TOA; forcing at the tropopause with stratospheric adjustment takes some of that into account; sensitivity to forcing at the tropopause with stratospheric adjustment will generally be different from sensitivity to forcing without stratospheric adjustment and both will generally be different from forcing at TOA before stratospheric adjustment; forcing at TOA after stratospehric adjustment is identical to forcing at the tropopause after stratospheric adjustment).

Indeed, this was found to be true for any of several different published volcanic forcing series for the past millennium, regardless of the precise geometric scaling used to estimate radiative forcing from volcanic optical depth, and regardless of the precise climate sensitivity assumed.

Radiative transfer models were never developed to estimate radiative forcing; they have entirely different, very practicRadiative transfer models were never developed to estimate radiative forcing; they have entirely different, very practicradiative forcing; they have entirely different, very practical, uses.

First, the Clarke et al. (2007) scenario considered a slightly different definition of radiative forcing than RCP4.5.

Due to the important role of ozone in driving temperature changes in the stratosphere as well as radiative forcing of surface climate, several different groups have provided databases characterizing the time - varying concentrations of this key gas that can be used to force global climate change simulations (particularly for those models that do not calculate ozone from photochemical principles).

Therefore, the uncertainties in ozone changes in the tropical lower stratosphere and their characterization in different databases using regression fits constitute a major barrier to understanding temperature trends and radiative forcing.

Contributions of the different greenhouse gases to total radiative forcing in the RCP4.5 scenario

Different models may find different contributions of the various gases to radiative forcing due to underlying pollution abatement assDifferent models may find different contributions of the various gases to radiative forcing due to underlying pollution abatement assdifferent contributions of the various gases to radiative forcing due to underlying pollution abatement assumptions.

The effect on radiative forcing of assuming different values for indirect aerosol forcing.

Obviously I have written many thousands of comments on at least 30 or 40 different climate blogs (and literally hundreds of different social media climate threads) and these cynical remarks are typical at first until people start to realise that I know my stuff and what I write is first - in - the - world breakthrough science that turns the radiative forcing greenhouse conjecture on its head.

Figure 7.18 Annual mean top of the atmosphere radiative forcing due to aerosol — radiation interactions (RFari, in W m — 2) due to different anthropogenic aerosol types, for the 1750 — 2010 period.

The radiative forcing potential of different climate geoengineering options [PDF].

High and low cloud have different optical properties — so it matters less to know the quantity of cloud than to know the changes in cloud radiative forcing.

So the 3.7 W m - 2 calculation for global radiative forcing could be refined perhaps by an improved experimental design (not necessarily by improved radiative transfer models) running RT models at each grid cell over the globe, over the diurnal cycle and the annual cycle for say 30 years, for the two different CO2 concentrations, such a detailed calculation would refine the 3.7 value.

Inverse modeling using Kaya's identity could identify the number of different pathways among the various combinations of possible input variables that could result in a specific radiative forcing scenario (say + / - 10 %).

So I don't think you can make up numbers for future warming much different than the recent past, because we're already coming down from peak rates of radiative forcing.

The second point means that it may be more difficult to distinguish between the response to different factors than one might expect, given the differences in radiative forcing.»

These different SAT trends occur despite the fact that both simulations were subject to the identical radiative forcing and were conducted with the same model, highlighting the role of internal atmospheric circulation variability in any single model run.

The DALR is established in Earth's atmosphere by vertically moving macroscopic parcels of air driven by thermal convection between volumes and surfaces at different temperatures, temperature gradients maintained by diurnal solar forcing and continual radiative cooling.

In every IPCC report there is a graph showing the different contributions to radiative forcing since the pre-industrial era.

Methane does produce some stratospheric water vapor in AOGCMs and therefore a forcing slightly different from simple radiative transfer calculations.

Radiative forcing (RF)[1] is a concept used for quantitative comparisons of the strength of different human and natural agents in causing climate change.

S1 and Table S2), (iii) different values of b for radiative forcing obtained by fitting Eq.

Houghton (2004: 259) explains that when converting from carbon dioxide only concentrations to carbon dioxide equivalent concentrations, the amount that needs to be added varies with different concentrations of greenhouse gases as the relationship between radiative forcing and concentration is non-linear.