Sentences with phrase «radiative effects of aerosols»

The direct and indirect radiative effects of aerosols suspended in the atmosphere above clouds (ACA) are a highly uncertain component of both regional and global climate.

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

In this paper we present results from various field experiments demonstrating the contribution that the multi-angle multi-spectral photopolarimetric remote sensing measurements of the NASA Glory mission will make to the determination of the direct and indirect radiative effects of aerosols.

Some models include volcanic effects by simply perturbing the incoming shortwave radiation at the top of the atmosphere, while others simulate explicitly the radiative effects of the aerosols in the stratosphere.

«The Radiative Effect of Aerosols in the Earth's Atmosphere.»

But even if this is a result of the GISS model, this largely depends on the assumptions made in the model for e.g. amounts and radiative effect of aerosols, which are far from settled.

Myhre, G., N. Bellouin, T.F. Berglen, T.K. Berntsen, O. Boucher, A. Grini, I.S.A. Isaksen, M. Johnsrud, M.I. Mishchenko, F. Stordal, and D. Tanre, 2007: Comparison of the radiative properties and direct radiative effect of aerosols from a global aerosol model and remote sensing data over ocean.

Not exact matches

Spanish and Portuguese researchers have analysed the composition and radiative effect of desert aerosols during two episodes which simultaneously affected Badajoz (Spain) and Évora (Portugal) in August 2012.

During this event, the aerosols stayed close to the surface due to the presence of a anticyclone hovering over the study region at sea - level, «reducing the amount of shortwave irradiance reaching the surface and causing greater radiative cooling,» states Obregón, who likens the effects of desert dust with those resulting from certain forest fires or episodes of high pollution.

For this reason, a group of researchers from Extremadura (Spain) and Portugal has analysed the radiative effect of a type of natural aerosol (the dust from the desert areas), of great interest to the Iberian Peninsula due to the proximity of the Sahara desert.

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.

That's far from the worst flaw in his calculation, since his two biggest blunders are the neglect of the radiative cooling due to sulfate aerosols (known to be a critical factor in the period in question) and his neglect of the many links in the chain of physical effects needed to translate a top of atmosphere radiative imbalance to a change in net surface energy flux imbalance.

The top priorities should be reducing uncertainties in climate sensitivity, getting a better understanding of the effect of climate change on atmospheric circulation (critical for understanding of regional climate change, changes in extremes) and reducing uncertainties in radiative forcing — particularly those associated with aerosols.

Can any of the experts lurking here refer me to any updates to the anthropogenic direct effect aerosol radiative forcing digram — Figure 6.8 -(Figure 401) in the TAR?

Geophysical Fluid Dynamics Laboratory general circulation model investigation of the indirect radiative effects of anthropogenic sulfate aerosol Journal of Geophysical Resarach, 2005

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).

Satellite observations do play, however, a key role for evaluating models of the indirect aerosol radiative effect (Ghan et al., 2001b).

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.

The direct and indirect radiative effects of biogenic secondary organic aerosol.

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.

Given our very short and spotty data on the relative abundance (or importance) of the majority of these aerosols, and given our very poor understanding of the direct, indirect, and side effects of the majority of these aerosols, any numbers that anyone generates about their abundance, importance, or total radiative forcing are going to be a SWAG.

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

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.

The effect of anthropogenic black carbon (BC) aerosol on snow is of enduring interest due to its role in aerosol radiative forcing and further consequences for Arctic and global climate change.

I may have to re-read the Wild paper and again look exactly for what I failed to find the first time: local temperature observations on the surface matching the expected effects of the aerosol radiative forcings the paper does talk a lot about.

The complexity of radiative - dynamical response forced by volcanic impacts suggests that it is important to calculate aerosol radiative effects interactively within the model rather than prescribe them (Andronova et al., 1999; Broccoli et al., 2003).

But including aerosol indirect effects on radiative forcing has made it easier to generate a greater variety of 20th century simulations without affecting other aspects of the climate simulation as strongly.

However, if one converts the total effects of all greenhouse gases, aerosols, etc. into an equivalent increase in CO2 concentration (by reference to their effective radiative forcing RF, that from a doubling of CO2 being F2xCO2), then what you suggest would be pretty much in line with the generic definition of TCR in Section 10.8.1 of AR5 WGI:

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.

The effects of aerosols and landuse changes reduce radiative forcing so that the net forcing of human activities is in the range of 311 to 435 ppm CO2 - eq, with a central estimate of about 375 ppm CO2 - eq.»

Regional effects of aerosol forcing are large; regional mean values of anthropogenic aerosol radiative forcing can be factors of 5 to 10 higher than the global mean values of 0.5 to 1.5 W m − 2 (IPCC, 2001).

absorbing aerosols, which lead to a positive radiative forcing of the troposphere with little net radiative effect at the top of the atmosphere;

Lohmann et al. (2000) predicted a radiative impact for the combined effect (i.e., first and second effects) of -1.3 and -0.9 Wm - 2 for externally and internally mixed carbonaceous aerosols, respectively.

As noted earlier, the IPCC's latest report indicates that the current radiative forcing of non-carbon dioxide greenhouse gases and aerosols effectively cancel each other, so that the net effect of all radiative forcing components is currently roughly equal to the effect of carbon dioxide alone.

They found that changes in atmospheric ionization during the 11 - year solar cycle, and the resulting variations in aerosol formation, produced a globally asymmetric radiative forcing with a net cloud albedo effect of − 0.05 W m − 2.

The whitehouse effect — Shortwave radiative forcing of climate by anthropogenic aerosols: An overview

Moreover, the semi-direct effect is not exclusive to absorbing aerosol, as potentially any radiative heating of the mid-troposphere can produce a similar response in a GCM (Hansen et al., 2005; see also Section 2.8).

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

Of particular interest, this approach allows calculation of a meaningful radiative forcing from the indirect or semidirect aerosol effectOf particular interest, this approach allows calculation of a meaningful radiative forcing from the indirect or semidirect aerosol effectof a meaningful radiative forcing from the indirect or semidirect aerosol effects.

effects of aerosols on cloud properties (including cloud fraction, cloud microphysical parameters, and precipitation efficiency), which may modify the hydrological cycle without significant radiative impacts;

The standard explanation for the post 1970s warming is that the radiative effect of greenhouse gases overcame shortwave reflection effects due to aerosols [Mann and Emanuel, 2006].

When partnered with cloud remote sensing observations the radiation measurements and retrievals allow the characterization of cloud and aerosol radiative effects at the surface, which is essential in order to quantify the amount of radiative energy available at the surface to interact with heating the air, evaporating water, and interacting with clouds and greenhouse gasses in the atmosphere.

2) The effects of clouds and aerosols on radiative heat transfer, which are many and varied and still being studied with many questions open.

The complexity of radiative - dynamical response forced volcanic impacts suggests that it is important to calculate aerosol radiative effects interactively within the model rather than prescribe them.

Yu, H., Y.J. Kaufman, M. Chin, G. Feingold, L.A. Remer, T.L. Anderson, Y. Balkanski, N. Bellouin, O. Boucher, S. Christopher, P. DeCola, R. Kahn, D. Koch, N. Loeb, M.S. Reddy, M. Schulz, T. Takemura, and M. Zhou, 2006: A review of measurement - based assessment of aerosol direct radiative effect and forcing.

Neither was the effect of anthropogenic sulphate aerosols, except to note in the FAR that «it is conceivable that this radiative forcing has been of a comparable magnitude, but of opposite sign, to the greenhouse forcing earlier in the century».

The level of scientific understanding of radiative forcing is ranked by the AR4 (Table 2.11) as high only for the long - lived greenhouse gases, but is ranked as low for solar irradiance, aerosol effects, stratospheric water vapor from CH4, and jet contrails.

In terms of sulphate aerosols, both the direct radiative effects and the indirect effects on clouds were acknowledged, but the importance of carbonaceous aerosols from fossil fuel and biomass combustion was not recognised (Chapters 2, 7 and 10).