Sentences with phrase «radiative effect of clouds»

All these issues must be taken into account when calculating the radiative effect of clouds, as is done in the radiative calculations by the ISCCP group.

This would require the radiative effect of clouds to change from one that increases atmospheric radiative absorption by about \ (0.5 \, \ hbox -LCB- Wm -RCB- ^ -LCB--2 -RCB- \, \ hbox -LCB- K -RCB- ^ -LCB--1 -RCB- \) to one that decreases it by \ -LRB--3.5 \, \ hbox -LCB- Wm -RCB- ^ -LCB--2 -RCB- \, \ hbox -LCB- K -RCB- ^ -LCB--1 -RCB- \).

Thus, while the net radiative effect of clouds is that of warming (cooling) across the tropics during La Niña (El Nino) events, the magnitude is quite small and varies greatly from one event to another..»

The radiative effect of clouds on the shortwave fluxes is computed as a seasonally varying (but fixed from one year to the next) and spatially varying atmospheric albedo.

Sally, who was nominated by Dr. Beat Schmid, Associate Director, Atmospheric Sciences and Global Change Division, was honored for her exceptional contribution in the field of atmospheric science, particularly in her efforts to improve understanding of the radiative effect of clouds and aerosols on the Earth's atmosphere and their representation in climate models.

The other two shortlisted missions — which had been whittled down from an original list of over 20 possibilities — were CoReH2O, which sought to model the water balance in glaciers and snow - covered areas, and PREMIER, which aimed to study chemical processes in the upper troposphere and lower stratosphere and the radiative effects of clouds.

Shown are changes in the radiative effects of clouds and in precipitation accompanying a uniform warming (4 °C) predicted by four models from Phase 5 of the Coupled Model Inter-comparison Project (CMIP5) for a water planet with prescribed surface temperatures».

The measurements are only for clear sky conditions, to remove the complexity associated with the radiative effects of clouds (they did this by removing the measurements that appeared to be under cloudy conditions).

There is some uncertainty in the water vapor and cloud feedback strength, but this is not a serious uncertainty since water vapor and clouds are constrained by the Clausius - Clapeyron relation, and since the SW and LW radiative effects of clouds cancel each other to a large degree.

Not exact matches

The model calculations, which are based on data from the CLOUD experiment, reveal that the cooling effects of clouds are 27 percent less than in climate simulations without this effect as a result of additional particles caused by human activity: Instead of a radiative effect of -0.82 W / m2 the outcome is only -0.60 W / m2.

Greenwald, T.J., G.L. Stephens, S.A. Christopher, and T.H.V. Haar, 1995: Observations of the global characteristics and regional radiative effects of marine cloud liquid water.

Lin, W.Y., and M.H. Zhang, 2004: Evaluation of clouds and their radiative effects simulated by the NCAR Community Atmospheric Model against satellite observations.

Four and a half billion years after its birth, the shrouded planet is much too hot to support the presence of liquid water on its surface because of its dense carbon dioxide atmosphere and sulfuric acid clouds, which retain too much radiative heat from the Sun through a runaway greenhouse effect.

While many basic aspects of physics can be included (conservation of mass, energy etc.), many need to be approximated for reasons of efficiency or resolutions (i.e. the equations of motion need estimates of sub-gridscale turbulent effects, radiative transfer codes approximate the line - by - line calculations using band averaging), and still others are only known empirically (the formula for how fast clouds turn to rain for instance).

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)?

He goes so far as to say that the IPCC is biased against «internal radiative forcing,» in favor of treating cloud effects as feedback.

«(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)?»

(Water vapor and low - level clouds can have a big effect on the radiative balance of the surface.)

(Note that radiative forcing is not necessarily proportional to reduction in atmospheric transparency, because relatively opaque layers in the lower warmer troposphere (water vapor, and for the fractional area they occupy, low level clouds) can reduce atmospheric transparency a lot on their own while only reducing the net upward LW flux above them by a small amount; colder, higher - level clouds will have a bigger effect on the net upward LW flux above them (per fraction of areal coverage), though they will have a smaller effect on the net upward LW flux below them.

Kasting had one very primitive go at a radiative - convective study of the effect of clouds on runaway greenhouse, which suggested that clouds might prevent the whole ocean from going aloft.

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).

wilt, the paper you cite describes what in their view is a «small but statistically significant effect of cosmic rays on cloud formation, which in no way invalidates the large and significant effects of human emissions on the current anthropogenic radiative forcing budget of the atmosphere.

Indirect aerosol effect - Aerosols may lead to an indirect radiative forcing of the climate system through acting as cloud condensation nuclei or modifying the optical properties and lifetime of clouds.

In addition, some models include the indirect effects of tropospheric sulphate aerosols on clouds (e.g., Tett et al., 2002), whereas others consider only the direct radiative effect (e.g., Meehl et al., 2004).

To evaluate the global effects of aerosols on the direct radiative balance, tropospheric chemistry, and cloud properties of the earth's atmosphere requires high - precision remote sensing that is sensitive to the aerosol optical thickness, size istribution, refractive index, and number density.

A 1 % decrease in cloud cover has a slightly higher radiative effect as all the observed loss of Arctic sea ice to date has had.

(Ramanathan and Inamdar 1989) So a 1 % decrease in cloud cover has a slightly higher radiative effect as all the observed loss of Arctic sea ice to date has had.

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.

The effect of this mixed dust - pollution plume on the Pacific cloud systems and the associated radiative forcing is an outstanding problem for understanding climate change and has not been explored.

For instance — changes in upwelling of frigid sub-surface water having an effect on clouds and that influencing global energy dynamics — as shown in satellite radiative flux data.

DMS is the primary source in the sulfate mass budget over the remote ocean west of 80 ° W. • The first aerosol indirect effect has been observationally quantified over the SEP, with cloud thinning of the more polluted coastal clouds mitigating the overall radiative impact.

adding two variables that were requested in the ACCMIP Word document but not explained in the spreadsheet: the longwave and the shortwave cloud radiative forcing with reference (fixed) composition, for diagnosis of aerosol indirect effect.

Radiative effects of surface - observed cloud cover anomalies, called «cloud cover radiative forcing (CCRF) anomalies,» are estimated based on a linear relationship to climatological cloud radiative forcing per unit cloRadiative effects of surface - observed cloud cover anomalies, called «cloud cover radiative forcing (CCRF) anomalies,» are estimated based on a linear relationship to climatological cloud radiative forcing per unit cloradiative forcing (CCRF) anomalies,» are estimated based on a linear relationship to climatological cloud radiative forcing per unit cloradiative forcing per unit cloud cover.

but this is the full CMIP3 ensemble, so at least the plot is sampling the range of choices regarding if and how indirect effects are represented, what the cloud radiative feedback & sensitivity is, etc. across the modelling community.

«This is the cause - versus - effect issue I have been harping on for years: You can not measure cloud FEEDBACK (temperature changes causing cloud changes) unless you can quantify and remove the effect of internal radiative FORCING (cloud changes causing temperature changes).

I am concerned about the apparent lack of correlation between the shortwave reflections and CRF as measured by the neutron counter (figure 6 on my DRAFT copy of «Cosmic rays modulation of the cloud effects on the radiative flux in the Southern Hemisphere Magnetic Anomaly region»).

The reprocessing of ISCCP produced a better distinction between the radiative effects of high opaque and cirrus clouds, in better agreement with the 3I results.

Ozone depletion in the late twentieth century was the primary driver of the observed poleward shift of the jet during summer, which has been linked to changes in tropospheric and surface temperatures, clouds and cloud radiative effects, and precipitation at both middle and low latitudes.

Andrew Lacis wrote: (3) Water vapor and clouds account for about 75 % the strength of the terrestrial greenhouse effect, but are feedback effects that require sustained radiative forcing to maintain their atmospheric distribution.

The second factor is the insulating effect of the atmosphere of which well over 90 % results from atmospheric water in the form of clouds and water vapour with the remaining 10 % due primarily from CO2 and ozone with just a slightly detectable effect from methane and a trivial effect from all the other gases named in tyhe Kyoto Accord that is so small it can't even be detected on measurements of the Earth's radiative spectrum.

The Pacific system resulted in a cloud radiative effect of 1.8 W / m2 over the tropical Pacific — based on Earth Radiation Budget Experiment data.

Instead, the aim of our Science paper was to illustrate as clearly and as simply as possible the basic operating principles of the terrestrial greenhouse effect in terms of the sustaining radiative forcing that is provided by the non-condensing greenhouse gases, which is further augmented by the feedback response of water vapor and clouds.

(3) Water vapor and clouds account for about 75 % the strength of the terrestrial greenhouse effect, but are feedback effects that require sustained radiative forcing to maintain their atmospheric distribution.

However, another source of uncertainty in the monthly mean zonal cloud radiative effects comes from the low frequency of clear - sky occurrence, when averaging over regions that correspond to the spatial resolution of general circulation models.

La Nina certainly cools the atmosphere with energy transferred between ocean and atmosphere — but different lines of evidence suggest that cloud radiative effects dominate with both oceans and atmosphere cooling.

This will tend to enhance the greenhouse effect, though the situation is complicated by the difficulty in both projecting changes in cloud formation and determining the radiative forcing effect of clouds.

Furthermore, a model that could realistically simulate the impact of increasing atmospheric particle concentration on climate must eventually include the simultaneous coupled effects of all the important atmospheric processes, such as fluid motions and cloud microphysics, in addition to the radiative transfer effects.»

He thought that this connection might occur via the effect of cosmic ray induced ionization on aerosol and cloud condensation nuclei and thus on the radiative properties of clouds.

Hartmnn derived an average cloud radiative forcing of -27.6 W / m ^ 2 — a net cooling — as the overall average effect of clouds on global climate.

And anyways, is the solar uncertainty (we understand the sign) really so much more greater than that associated with the effects of clouds on climate (see my recent post The cloud climate conundrum), where even the sign of the feedback is uncertain and the magnitude of cloud forcing swamps greenhouse gas radiative forcings.