Sentences with phrase «changing the albedo of»

This changes the albedo of the planet significantly, reducing total insolation and resulting in cooling.

In models that include indirect effects, different treatments of the indirect effect are used, including changing the albedo of clouds according to an off - line calculation (e.g., Tett et al., 2002) and a fully interactive treatment of the effects of aerosols on clouds (e.g., Stott et al., 2006b).

It's an approximation, but we should just have a new spherical system with an albedo a bit different from the first one, and it seems to me implausible that a few CO2 ppm added could change the albedo of this entire new system.

These algae can change the albedo of snow, affecting the rate of Arctic snowmelt.

This is largely because melting sea ice changes the albedo of high latitude oceans, and to a lesser extent because an inversion prevails at high latitudes, especially in winter, whereas at low latitudes the heating is convectively mixed througout the troposphere.

CO2 changes the albedo of the atmosphere in frequencies that are visible only to snakes and infrared imaging instruments.

Read more: Stanford University Aerosols Also Implicated in Glacier Melting, Changing Weather Patterns Other research examining the effects of soot on melting glaciers and changing weather pattens in South Asia has reached similar conclusions: Beyond increasing atmospheric warming, because the soot coats the surface of the snow and ice it changes the albedo of the surface, allowing it to absorb more sunlight and thereby accelerating melting.

This black carbon changes the albedo of the ice, causing it to reflect less sunlight and absorb more heat.

Black carbon can have another indirect effect by changing the albedo of snow and ice, but that's not the topic of this post.

Not exact matches

They found that in regions where the amount of snowfall was low and any snow that did settle was sublimating away, enough dust would have accumulated to change the surface albedo sufficiently so that the Earth absorbed sunlight and thawed (Journal of Geophysical Research — Atmospheres, DOI: 10.1029 / 2009jd012007, in press).

Their analysis reveals that the conversion of broadleaved forests to coniferous forests caused significant changes in evapotranspiration, the evaporation of water through leaves, and albedo, the amount of solar energy reflected from the Earth back into space.

The impact of grain size on albedo — the ratio between reflected and incoming solar radiation — is strong in the infrared range, where humans can't see, but satellite instruments can detect the change.

The boundaries of ancient valley walls are defined by textural and albedo changes and are also associated with lateral river migration.

These factors have decreased the region's albedo, or the fraction of incoming light that Earth reflects back into space — a change that the CERES instruments are able to measure.

A diminishing albedo in Arctic sea ice can be considered both the cause and effect of changes in sea ice.

Also about the ice - albedo feedback within 1K temperature oscillation the albedo will change of, let us say, 10 %, so for an increase of 1K the albedo will decrease from A = 0.3 to A = 0.27.

I guess I am surprised that with better understanding of the importance of water vapor feedback, sulfate aerosols, black carbon aerosols, more rapid than expected declines in sea ice and attendant decreases in albedo, effects of the deposition of soot and dust on snow and ice decreasing albedo, and a recognition of the importance of GHGs that were probably not considered 30 years ago, that the sensitivity has changed so little over time.

What G&T are missing is the linear effect of water vapour accelerating the ice albedo effect of change in size of the sea ice sheets.

Lynn, the increase of temperatures in the Arctic, is mainly the result of an inflow of warmer air from lower latitudes (with the current AO) and the change in albedo (mainly in summer).

That's pretty alarming, especially when considered in the context of other positive feedbacks including changes in albedo from melting icecaps and release of carbon and methane from thawing permafrost.

Model performance in reproducing the observed seasonal cycle of land snow cover may provide an indirect evaluation of the simulated snow - albedo feedback under climate change.

I can't tell where you got the figure but -3.5 W / m2 is about right for current understanding of «boundary condition» land albedo change between pre-industrial and LGM.

This method tries to maximize using pure observations to find the temperature change and the forcing (you might need a model to constrain some of the forcings, but there's a lot of uncertainty about how the surface and atmospheric albedo changed during glacial times... a lot of studies only look at dust and not other aerosols, there is a lot of uncertainty about vegetation change, etc).

There was more ice around in the LGM and that changes the weighting of ice - albedo feedback, but also the operation of the cloud feedback since clouds over ice have different effects than clouds over water.

You've hit on one of the weaknesses of the paper, as the model they use admittedly doesn't model changes in albedo (at least, not as a model output).

I guess a relatively small change in temperatures wouldn't affect the albedo of a flat highland near the poles.

The measured energy imbalance accounts for all natural and human - made climate forcings, including changes of atmospheric aerosols and Earth's surface albedo.

Specification now of a CO2 target more precise than < 350 ppm is difficult and unnecessary, because of uncertain future changes of forcings including other gases, aerosols and surface albedo.

The albedo and CO2 feedbacks amplified weak orbital forcings, the feedbacks necessarily changing slowly over millennia, at the pace of orbital changes.

In addition, since the global surface temperature records are a measure that responds to albedo changes (volcanic aerosols, cloud cover, land use, snow and ice cover) solar output, and differences in partition of various forcings into the oceans / atmosphere / land / cryosphere, teasing out just the effect of CO2 + water vapor over the short term is difficult to impossible.

I was interested not so much in the forcing effect of clouds themselves so much as the change in albedo which might result from a change in the overall extent of global cloud cover.

However, the Management and Guest Contributors at WUWT accept the basic truth that CO2, water vapor, and other «greenhouse gases» are responsible for an ~ 33ºC boost in mean Earth temperature, that CO2 levels are rising, partly due to our use of fossil fuels, that land use has changed Earth's albedo, and that this human actvity has caused additional warming.

eg how big is the «expected» impact on the climate / temps etc from that kind of change / feedback in ASI albedo

The model considers all relevant feedback processes caused by changes of water vapour, lapse - rate, surface albedo or convection and evaporation.

While the local, seasonal climate forcing by the Milankovitch cycles is large (of the order 30 W / m2), the net forcing provided by Milankovitch is close to zero in the global mean, requiring other radiative terms (like albedo or greenhouse gas anomalies) to force global - mean temperature change.

This estimate is generous to the GCR hypothesis, since the cumulus - to - water albedo shift exaggerates the true change of low clouds, and I need bond albedos in my calculation and I'm using visible albedos.

Other factors would include: — albedo shifts (both from ice > water, and from increased biological activity, and from edge melt revealing more land, and from more old dust coming to the surface...); — direct effect of CO2 on ice (the former weakens the latter); — increasing, and increasingly warm, rain fall on ice; — «stuck» weather systems bringing more and more warm tropical air ever further toward the poles; — melting of sea ice shelf increasing mobility of glaciers; — sea water getting under parts of the ice sheets where the base is below sea level; — melt water lubricating the ice sheet base; — changes in ocean currents -LRB-?)

If we allow that all those clouds are cumulus with an albedo of 0.8 and that they block water with an albedo of 0.1, that translates to a change in global albedo of 0.014.

A conceptual model is presented where, through a number of synergistic processes and positive feedbacks, changes in the ultraviolet / blue flux alter the dimethyl sulphide flux to the atmosphere, and in turn the number of cloud condensation nuclei, cloud albedo, and thus sea surface temperature.

I guess I am surprised that with better understanding of the importance of water vapor feedback, sulfate aerosols, black carbon aerosols, more rapid than expected declines in sea ice and attendant decreases in albedo, effects of the deposition of soot and dust on snow and ice decreasing albedo, and a recognition of the importance of GHGs that were probably not considered 30 years ago, that the sensitivity has changed so little over time.

Pretty much all existing GCMs take into account changes in cloud albedo effects (though these are still characterized by a fairly high level of uncertainty).

On the possibility of a changing cloud cover «forcing» global warming in recent times (assuming we can just ignore the CO2 physics and current literature on feedbacks, since I don't see a contradiction between an internal radiative forcing and positive feedbacks), one would have to explain a few things, like why the diurnal temperature gradient would decrease with a planet being warmed by decreased albedo... why the stratosphere should cool... why winters should warm faster than summers... essentially the same questions that come with the cosmic ray hypothesis.

In our own modelling, we have improved the calculations to reduce the amount of numerical diffusion (which helped a lot), and increased resolution (which also helped), but changes to the ocean model also have a big impact, as do Arctic cloud processes and surface albedo parameterisations, so it gets complicated fast.

What G&T are missing is the linear effect of water vapour accelerating the ice albedo effect of change in size of the sea ice sheets.

For example, the ice age — interglacial cycles that we have been locked in for the past few million years seem to be triggered by subtle changes in the earth's orbit around the sun and in its axis of rotation (the Milankovitch cycles) that then cause ice sheets to slowly build up (or melt away)... which changes the albedo (reflectance) of the earth amplifying this effect.

Eventually, when we know more about the effects of the mechanisms involved, fluctuations in cosmic rays could be incorporated in helping model cloud albedo changes.

The resulting increased / decreased ice is amplified by «various feedbacks, including ice - albedo, dust, vegetation and, of course, the carbon cycle which amplify the direct effects of the orbital changes.»

From the point of view of climate modelling the all - gone moment isn't as important as the magnitude of the change in albedo — particularly in the spring, summer and autumn.

This implies a forcing of 3 W / m2 for albedo changes presumably due to additional ice / snow sheets.

The change in albedo for such a long period of time each year is bound to cause all sorts of weird weather that we have never before experienced.