Sentences with phrase «surface radiative forcing»

Compute the surface radiative forcing and its amplification by the atmospheric warming in a manner following Myhre and Stordal 1997, using gridded global fields of of the input variables obtained from observations (e.g. the ECMWF reanalysis, ISCCP clouds, satellite ozone, some sort of aerosol optical depth from satellite.

Today I read a paper that claims to measure the increase in surface radiative forcing by CO2 during the same ten - year period as 0.2 Wm - 2.

This is called surface radiative forcing, and the measurements are part of the empirical evidence that CO2 is causing the warming.

Considering the surface radiative forcing may enable quantification of the effects of aerosols on the surface

However, to assess climate response beyond surface temperature change (e.g., changes in precipitation, latent heat release from surface, or in the surface heat and moisture balance), it becomes necessary to understand the surface radiative forcing for all forcings.

Together with the TOA radiative forcing, surface radiative forcing also may provide information about the extent to which forcings affect the atmospheric lapse rate, with implications for precipitation and mixing.

Observational determination of surface radiative forcing by CO2 from 2000 to 2010 «Here we present observationally based evidence of clear - sky CO2 surface radiative forcing that is directly attributable to the increase, between 2000 and 2010, of 22 parts per million atmospheric CO2.»

Actually, we're using the term climate sensitivity in the same sense, the equilibrium response of mean temp to the surface radiative forcing associated with CO2 doubling.

Observational determination of surface radiative forcing by CO2 from 2000 to 2010.

Not exact matches

«What is most interesting is that there are big shifts in the surface mass balance that occur from only very small changes in radiative forcing,» said Ullman, who is in OSU's College of Earth, Ocean, and Atmospheric Sciences.

Pierre, could you comment on what, exactly, is new in the recent Philipona paper, compared with the two similar papers they published last year («Greenhouse forcing outweighs decreasing solar radiation driving rapid temperature rise over land», «Radiative forcing — measured at Earth's surface — corroborate the increasing greenhouse effect»)?

Where «dT» is the change in the Earth's average surface temperature, «λ» is the climate sensitivity, usually with units in Kelvin or degrees Celsius per Watts per square meter (°C / [W - m - 2]-RRB-, and «dF» is the radiative forcing.

He then uses what information is available to quantify (in Watts per square meter) what radiative terms drive that temperature change (for the LGM this is primarily increased surface albedo from more ice / snow cover, and also changes in greenhouse gases... the former is treated as a forcing, not a feedback; also, the orbital variations which technically drive the process are rather small in the global mean).

Where «dT» is the change in the Earth's average surface temperature, «λ» is the climate sensitivity, usually with units in Kelvin or degrees Celsius per Watts per square meter (°C / [W m - 2]-RRB-, and «dF» is the radiative forcing, which is discussed in further detail in the Advanced rebuttal to the «CO2 effect is weak» argument.

The regional climate feedbacks formulation reveals fundamental biases in a widely - used method for diagnosing climate sensitivity, feedbacks and radiative forcing — the regression of the global top - of - atmosphere radiation flux on global surface temperature.

The surface temperature change is proportional to the sensitivity and radiative forcing (in W m - 2), regardless of the source of the energy imbalance.

Gregory et al. (2002) used observed interior - ocean temperature changes, surface temperature changes measured since 1860, and estimates of anthropogenic and natural radiative forcing of the climate system to estimate its climate sensitivity.

Abstract:» The sensitivity of global climate with respect to forcing is generally described in terms of the global climate feedback — the global radiative response per degree of global annual mean surface temperature change.

«We use a massive ensemble of the Bern2.5 D climate model of intermediate complexity, driven by bottom - up estimates of historic radiative forcing F, and constrained by a set of observations of the surface warming T since 1850 and heat uptake Q since the 1950s... Between 1850 and 2010, the climate system accumulated a total net forcing energy of 140 x 1022 J with a 5 - 95 % uncertainty range of 95 - 197 x 1022 J, corresponding to an average net radiative forcing of roughly 0.54 (0.36 - 0.76) Wm - 2.»

The researchers discovered that periods of increased radiative forcing could produce drought - like conditions that extended indefinitely and that these conditions were closely tied to prolonged changes in Pacific Ocean surface temperatures.

Your earlier # 182 was equally disconcerting where you quoted Norris and Slingo (2009) saying «At present, it is not known whether changes in cloudiness will exacerbate, mitigate, or have little effect on the increasing global surface temperature caused by anthropogenic greenhouse radiative forcing.»

Since OHC uptake efficiency associated with surface warming is low compared with the rate of radiative restoring (increase in energy loss to space as specified by the climate feedback parameter), an important internal contribution must lead to a loss rather than a gain of ocean heat; thus the observation of OHC increase requires a dominant role for external forcing.

I wrote: «CO2 has been shown in laboratory conditions to increase radiative forcing at the surface.»

Consequently, as they say slightly earlier in the abstract: «At present, it is not known whether changes in cloudiness will exacerbate, mitigate, or have little effect on the increasing global surface temperature caused by anthropogenic greenhouse radiative forcing.»

Abstract:» The sensitivity of global climate with respect to forcing is generally described in terms of the global climate feedback — the global radiative response per degree of global annual mean surface temperature change.

As an aside, the radiative forcing by aerosols (in both long wave and solar radiation at the tropopause) is not the same as global dimming (which is a solar radiation effect at the surface) though they are related.

[Response: The radiative forcings are strictly defined at the tropopause, not at the surface.

The lower troposphere is also expected to have a linear relationship to the radiative forcing although amplified relative to the surface; e.g. see Figure 5.6 for the tropics in CCSP 1.1.

This is about 0.03 Watt / m ^ 2 of Earth's surface while 2 x CO2 causes a radiative forcing of 3.7 Watt / m ^ 2.

Overall, humans have caused an additional heating (radiative forcing) of 2.3 watts per square meter of Earth surface — as of 2011.

Climate models may therefore lack — or incorrectly parameterize — fundamental processes by which surface temperatures respond to radiative forcings... In contrast with climate model simulations, the zonal surface temperature changes... do not increase rapidly from mid to high latitudes.»

Summary for Policymakers Chapter 1: Introduction Chapter 2: Observations: Atmosphere and Surface Chapter 3: Observations: Ocean Chapter 4: Observations: Cryosphere Chapter 5: Information from Paleoclimate Archives Chapter 6: Carbon and Other Biogeochemical Cycles Chapter 7: Clouds and Aerosols Chapter 8: Anthropogenic and Natural Radiative Forcing Chapter 8 Supplement Chapter 9: Evaluation of Climate Models Chapter 10: Detection and Attribution of Climate Change: from Global to Regional Chapter 11: Near - term Climate Change: Projections and Predictability Chapter 12: Long - term Climate Change: Projections, Commitments and Irreversibility Chapter 13: Sea Level Change Chapter 14: Climate Phenomena and their Relevance for Future Regional Climate Change Chapter 14 Supplement Technical Summary

That forcing is just under 4W / m ^ 2, so put differently, equilibrium climate sensitivity is the equilibrium expected surface warming for a radiative forcing of 1W / m ^ 2, divided by 4.

Secondly, unlike the global average surface temperature trend, which has a lag with respect to radiative forcing, there is no such lag when heat content is measured in Joules (see http://blue.atmos.colostate.edu/publications/pdf/R-247.pdf).

The stratosphere will, absent sustained non-radiative perturbations (see 57i), approach radiative equilibrium on a time scale under a year (Holton, «An Introduction to Dynamic Meteorology», 1992, p. 410), so taking stratospheric adjustment to instantaneous stratospheric forcing first and then applying the adjusted tropopause - level forcing to the troposphere + surface and stratospheric feedbacks is similar to the actual order of events in reality.

the problem is that this definition implicitly assumes that the global, time average surface temperature is a definite single valued function of the radiative average forcing, which is far from being true since there are considerable horizontal heat transfer modifying the latitudinal repartition of temperature: the local vertical radiative budget is NOT verified.

«Radiative forcing [RF] can be related through a linear relationship to the global mean equilibrium temperature change at the surface (delta Ts): delta Ts = lambda * RF, where lambda is the climate sensitivity parameter (e.g., Ramaswamy et al., 2001).

(PS we are considering the climate sensitivity to be in terms of changes in global - time average surface temperature per unit global - time average radiative forcing, though one could also define other sensitivities for other measures of climate).

To be sure, some of these effects (such as the impact of irrigation on surface water vapour, or land use changes on evapotranspiration) are not easily dealt with in terms of the tropospheric radiative forcing — a point that was well made in the National Academies report on radiative forcing (on which Dr. Pielke was an author).

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).

Myhre, G. and A. Myhre, Uncertainties in radiative forcing due to surface albedo changes caused by land use changes, J. Climate, 16, 1511 - 1524, 2003.

The term «climate sensitivity» refers to the steady - state increase in the global annual mean surface air temperature associated with a given global mean radiative forcing.

I clearly see that the change in surface temperature and TOA radiative forcing simulated by the model depends upon the model complexity, for example, how the ocean circulations are represented.

But the change in surface temperature would also cause a change in radiative forcing.

Lee and I already discussed the fact that AMO can change surface temperatures through strictly internal variability and by changing radiative forcings.

The climate sensitivity is defined as the equilibrated change in global mean surface air temperature (SAT) for a given change in radiative forcing and has been a major focus of climate research over the last three decades.

The equilibrium climate sensitivity refers to the equilibrium change in average global surface air temperature following a unit change in the radiative forcing.

The TRANSLATION of Radiative Forcing to the Surface is an unexplained phenomenon.

I like the definition of climate sensitivity as «change in surface temperature per unit change in radiative forcing».

In summary, the LES framework with closed surface energy balance constrains the change in surface fluxes and especially LHF to be consistent with the radiative forcing, which is important for obtaining realizable MBL and low - cloud responses to warming.