Sentences with phrase «so albedo»

So albedo must from only geometrical - mathematical reasons be a product of the spherical shape limiting the finite amount of heat available.

There is a lot less ice so albedo feedbacks are much more limited in extent.

The seasonal ice farther south is in the dark most of its life too as it forms in the winter so its albedo is meaningless.

Keep in mind there's a dearth of insolation at high latitudes so albedo becomes increasingly less important so snow cover over land doesn't mean as much.

The ocean also reflects increasingly more as the angle of the sun gets lower so albedo importance diminishes there too.

The Arctic Ocean losing its ice is almost certainly involved in the initiation of northern thermohaline demise, so albedo change will compensate.

So albedo change (owing to changes in orbital forcing, which is what melts the ice sheets) was comparable to, and probably larger than, the CO2 change.

Inceasing oxygen (for example form 20.9 to 30 percent) in my opinion would: Increasing scattering and so albedo, lowering temperature Increasing total pressure, broadening of absorption lines, rising temperature Increasing adiabate slope, rising SAT directly but decreasing water vapor, total effect??

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).

«Because access to the Arctic is so difficult, there is not much reliable data on albedo there,» explains Sebastian Gerland, who headed the AMORA project and is a research scientist at the Norwegian Polar Institute.

So the real choice is between exploring albedo modification openly or in relative secrecy, he says: «I believe in sunshine and democracy, and I really think this should be done by the U.S. government and in a transparent way.»

But he adds, «The albedo is already so ridiculously high that just a little more ridiculousness is OK.»

So if the occultation results hold up, then the density of Eris must be higher, 2.5 g / cm3 or more, and its albedo (reflectivity) at least 90 per cent.

«If you can time your emissions so they have the least impact then you will not trigger these very sensitive regions to start warming by this ice albedo feedback process.»

Other research signals that the albedo effect «causes so much warming that permafrost thaws even despite the cooling from shrubs,» he said.

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.

With higher precipitation, portions of this snow may not melt during the summer and so glacial ice can form at lower altitudes and more southerly latitudes, reducing the temperatures over land by increased albedo as noted above.

So it currently includes a [positive] contribution from the ice - albedo feedback, because our current climate possesses sea - ice that will be melted by a modest increase in temperatures.

The factors that determine this asymmetry are various, involving ice albedo feedbacks, cloud feedbacks and other atmospheric processes, e.g., water vapor content increases approximately exponentially with temperature (Clausius - Clapeyron equation) so that the water vapor feedback gets stronger the warmer it is.

As I understand Hansen he's saying: if we double CO2 this century (so upto about 550 - 600 ppm), that will mean a forcing of about 4 W / m2 and 3 degrees C warming in the short term (decades), and thru slow feedbacks (albedo + GHG) another 4 W / m2 and 3 degrees in the long term (centuries / millennia).

Slow insolation changes initiated the climate oscillations, but the mechanisms that caused the climate changes to be so large were two powerful amplifying feedbacks: the planet's surface albedo (its reflectivity, literally its whiteness) and atmospheric CO2 amount.

However, I had to wear my white dress, because it's perfect for being outside in the heat (white increases your albedo, and a higher albedo means more sunlight reflected off of you, so you don't feel as warm!).

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.

[1] CO2 absorbs IR, is the main GHG, human emissions are increasing its concentration in the atmosphere, raising temperatures globally; the second GHG, water vapor, exists in equilibrium with water / ice, would precipitate out if not for the CO2, so acts as a feedback; since the oceans cover so much of the planet, water is a large positive feedback; melting snow and ice as the atmosphere warms decreases albedo, another positive feedback, biased toward the poles, which gives larger polar warming than the global average; decreasing the temperature gradient from the equator to the poles is reducing the driving forces for the jetstream; the jetstream's meanders are increasing in amplitude and slowing, just like the lower Missippi River where its driving gradient decreases; the larger slower meanders increase the amplitude and duration of blocking highs, increasing drought and extreme temperatures — and 30,000 + Europeans and 5,000 plus Russians die, and the US corn crop, Russian wheat crop, and Aussie wildland fire protection fails — or extreme rainfall floods the US, France, Pakistan, Thailand (driving up prices for disk drives — hows that for unexpected adverse impacts from AGW?)

This comment is already longer than intended, so I'll leave further discussion of Albedo Restoration for later.

sigmaT ^ 4 is the upward blackbody radiation (based on stefan - boltzmann) at the surface, «a» is the albedo (reflectivity), so (1 - a) is the fraction of incident solar radiation that is absorbed by the planet.

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.

If this is so, let me ask this simple question: what is the more dominant contributor to the earth's albedo, the 60 - 70 % cloud cover or the various areas of snow / ice?

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.

So, clouds both warm and cool, and their overall effect upon climate depends upon the balance between albedo cooling and greenhouse warming.

About 6 %, so the Earth's albedo would be perhaps 0.2 and the temperature of surface and atmosphere would be 264 K.

Does more evaporation lead to more clouds and if so is the net effect of more clouds to increase albedo or to further increase GHE?

In LGM simulations land albedo changes are prescribed (at least in regards to ice sheets and altered topography due to sea level; there are feedback land albedo changes) so are a forcing, whereas sea ice is determined interactively by the model climate, so is a feedback in this framework.

So for example deglaciation warmed global mean temps by about 5 C over 10k years with a radiative forcing of about 6.5 W / m2 (total of both GHG increases and albedo decreases).

«If you can time your emissions so they have the least impact then you will not trigger these very sensitive regions to start warming by this ice albedo feedback process.»

Orbital forcing causes ice ages or ends them by redistributing incoming solar radiation over seasons and latitudes so that ice sheet growth or decay is more or less favorable on a regional basis, with a resulting global average albedo feedback.)

Kjell Arne Rekaa @ 72, although Venus is closer to the sun it has a much higher albedo than Earth, so it reflects more incoming solar energy back out to space before it can be absorbed.

The ambiguity over the definition of ice - free is not really important as far as the strong albedo feedbacks magnifying the warming of the region, so is kind of a red herring in the discussion.

This cooling all combines to let the ice extent spread further south (meaning an even higher albedo, less H2O, less CO2, etc., and so the ice age deepens and temperatures continue to drop).

I've sometimes thought that global cataclysms like the largest volcanic eruptions would disrupt the glacial records by many years, like Oruanui eruption c. 26500bp, as these would induce unrecorded behavior in weather and other things, f.e. the huge ash deposits might decrease the albedo so much a local melting event happens.

The formula So * (1 - albedo) * 0.25 = sigma T ^ 4 is valid only for an isothermal blackbody «bare rock» in space.

Depending on meridional heat transport, when freezing temperatures reach deep enough towards low - latitudes, the ice - albedo feedback can become so effective that climate sensitivity becomes infinite and even negative (implying unstable equilibrium for any «ice - line» (latitude marking the edge of ice) between the equator and some other latitude).

So we are left with little sense of how much some «average» macrovariables like albedo, vary day to day and hour by hour as clouds come and go and land use and natural cover vary

In fact, if the physics - based understanding of «equilibrium sensitivity» to any forcing is too low, then not only will CO2 have a greater effect, so too will all other forcings, such as: changes in the sun, in cloud cover, in albedo, etc..

Re 9 wili — I know of a paper suggesting, as I recall, that enhanced «backradiation» (downward radiation reaching the surface emitted by the air / clouds) contributed more to Arctic amplification specifically in the cold part of the year (just to be clear, backradiation should generally increase with any warming (aside from greenhouse feedbacks) and more so with a warming due to an increase in the greenhouse effect (including feedbacks like water vapor and, if positive, clouds, though regional changes in water vapor and clouds can go against the global trend); otherwise it was always my understanding that the albedo feedback was key (while sea ice decreases so far have been more a summer phenomenon (when it would be warmer to begin with), the heat capacity of the sea prevents much temperature response, but there is a greater build up of heat from the albedo feedback, and this is released in the cold part of the year when ice forms later or would have formed or would have been thicker; the seasonal effect of reduced winter snow cover decreasing at those latitudes which still recieve sunlight in the winter would not be so delayed).

In their latest Science paper submittal Jim Hansen, et al. argue that we must reduce atmospheric CO2 to below 350 ppm because so - called «slow feedbacks» such as changes in ice sheet albedo are occurring much faster than expected.

Is there a discernible point, maybe in a model, that includes reduced albedo in the summer, that might show an acceleration of melting above the average temperature increase curve for the region so that ocean warmth has an increasing role over atmospheric??

But new ice would only have this years soot burden to alter its albedo, so would perhaps be ably to resist this accelerating albedo - shift - driven runaway melting.

Ice has a much higher albedo than open water, so it reflects more energy from the sun back into space.