Sentences with phrase «albedo changes in»

Steve, I'm unsure why; Miller et al 2014 only discusses albedo changes in relation to the land use forcing.

Hall and Qu (2006) showed that differences among models in seasonal northern hemisphere surface albedo changes are well correlated with global - warming albedo changes in CMIP3 models.

The albedo change resulting from the snowline retreat on land is similarly large as the retreat of sea ice, so the combined impact could be well over 2 W / sq m. To put this in context, albedo changes in the Arctic alone could more than double the net radiative forcing resulting from the emissions caused by all people of the world, estimated by the IPCC to be 1.6 W / sq m in 2007 and 2.29 W / sq m in 2013.»

Albedo changes in the desert might make sense: blindingly white artificial salt pans come to mind as they should be cheap if brackish / salty bore water is available (though you would have to choose your topography carefully!).

The main albedo change in the last 60 years is probably ice / snow loss, which is another positive feedback to the change and not independent.

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 study used satellite data to compare summertime changes in Greenland's albedo from 1981 to 2012.

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.

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

Virtually ice - free summers in the arctic sea could well arrive by 2030, with troubling implications for accelerated albedo feedback and possibly disruptive changes in the jet stream.

Hall, A. & Qu, X. Using the current seasonal cycle to constrain the snow albedo feedback in future climate change.

If this change in global albedo is what is causing global warming, how did the process get started?

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.

For one thing, the fit neglects lags in the system (such as those resulting from ocean heat uptake) and it also neglects changes in albedo and other radiative factors.

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.

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).

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.

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.

[Response: UVic doesn't model changes in cloud albedo, but I'm quite sure it models changes in albedo due to sea ice and land ice.

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.

That is clearly the Milankovitch cycles that initiate the process — and CO2 and water vapor (along with changes in albedo due to snow and vegetation) are both feedbacks.

Parameters changed in PIOMAS calibration are typically the surface albedo and roughness, and the ice strength.

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 impossiblIn 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 impossiblin 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

How will albedo changes, increased rainfall and melt in Greenland affect ice degradation?

An increase in greenhouse absorbers or a change in the albedo have analogous impacts on the TOA balance.

Does the model accurately reproduce some basic phenomena that happens in the real world when you change the GHG, or the aerosols, solar radiation, or ice albedo?

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.

The change in ice volume and climate changes the planets albedo (how much sunlight is reflected) and affect carbon storage.

Perhaps you might want to read that paper as well as «Climate Change and Trace Gases», available in many places, which argues for an albedo flip mechanism and (relatively) short timescales for icesheet response to forcing, based on paleo data.

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.

As surfaces absorb roughly 100 times more solar energy than the CO2 in the atmosphere, future anthropogenic changes in both land and water albedo may figure significantly in climate policy outcomes.

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.

Changes in vegetation = > changes in albedo / CO2 Changes in vegetation = > changes in albedo / CO2 changes in albedo / CO2 levels.

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.

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.