Sentences with phrase «ice changes the albedo»

Floating ice changes albedo when it melts, not sea level.

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.

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.

Not exact matches

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

Scripps graduate student Kristina Pistone and climate scientists Ian Eisenman and Veerabhadran Ramanathan used satellite measurements to calculate Arctic albedo changes associated with the changing sea ice cover.

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.

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.

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).

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.

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 impossible.

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

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?

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-?)

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.

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.

I've been told by a friend that James Hansen once said that albedo changes from melting the arctic sea ice would capture as much additional heat as doubling CO2.

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.

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.»

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

The Arctic sea ice melting out above 75N would have almost no impact at all if that is the forcing change of glaciers down to Chicago and sea ice down to 45N (at lower latitudes where the Albedo has much more impact).

This was a relatively stable climate (for several thousand years, 20,000 years ago), and a period where we have reasonable estimates of the radiative forcing (albedo changes from ice sheets and vegetation changes, greenhouse gas concentrations (derived from ice cores) and an increase in the atmospheric dust load) and temperature changes.

Hansen et al. (1993) calculated the ice age forcing due to surface albedo change to be 3.5 + / - Wm ^ -2.

, (3) changes in surface albedo of snow & ice due to changes in temperature and deposition of mineral and black carbon particulates, and last, but arguably most significantly (4) the intensity of the positive feedback that comes from the inevitable -LRB-?)

Volume change includes both the area reduction (change in ice coverage, albedo, and heat absorption / reflection) and the thickness (vulnerability).

As for irreversible, if an ice sheet starts flowing, or if an albedo change from sea ice gets locked in, I could imagine a climate change being essentially irreversible even if CO2 was brought back down, but it's just speculation, nothing more.

«Soot snow / ice albedo climate forcing is not included in Intergovernmental Panel on Climate Change evaluations.

What other things in the Earth system will change when it warms up that will affect how much SW radiation is reflected back into space [eg ice - albedo feedback, cloud changes] or affect what proportion of emitted LW radiation is allowed to escape to space [eg Water Vapour, cloud changes].

For instance, the effect of soot making snow and sea ice darker has a higher efficacy than an equivalent change in CO2 with the same forcing, mainly because there is a more important ice - albedo feedback in the soot case.

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.

A few productive search terms will give him a good start: tundra albedo change «sea ice» algae «primary productivity» permafrost

I am under the impression that it is driven by CO2 mediated ice - loss that generates albedo changes resulting in positive feedbacks that increase further melting.

Since it reflects the capacity of the climate system to absorb heat, it may be influenced by the planetary albedo (sea - ice and snow) and ice - caps, which respond to temperature changes.

Ice cover changes albedo.

(In the full 4 - dimensional climate, responses can also tend spread horizontally by convection (advection) and temporally by heat capacity, though «fingerprints» of horizontal and temporal variations in RF (externally imposed and feedback — snow and ice albedo, for example) can remain — this spreading is somewhat different as it relies in part on the circulation already present as well as circulation changes)

My reasoning was that, iirc, black carbon has played an important role in the ice loss by changing albedo.

It could be hiding in melting ice, or through albedo changes there may be no added heat at all.

Isn't there an even bigger issue that approx half of the temperature amplitude between glacial and interglacial isn't actually due to CO2 or other GHG, but to albedo changes (ice albedo feedback)?

The changes in total insolation resulting from spreading ice (and the accompanying change in albedo) by themselves are no where near enough to drop temperatures by the amount needed.

In particular, there are «slow» responses to the imbalance that are seen in the glacial record — CO2 and methane increase with a slow lag as temperature rises in response to the orbital changes, and the albedo effect that reduces incoming sunlight decreases as the ice melts, also with a slow lag.

It doesn't have to be CO2 — in this case it's seasonal insolation changes which cause an expansion of ice cover which cause a change in the planet's overall albedo.

Both are related to feedback mechanisms which can amplify or dampen initial changes, such as the connection between temperature and the albedo associated with sea - ice and snow.

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).

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.

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.

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