Sentences with phrase «albedo effect of clouds»

Explain why the surface of venus, which only receives some 2.5 % of the sun's energy due to the albedo effect of the clouds can have a temperature of 500C.

In contrast, the albedo effect of clouds goes up a bit slower with water content than the greenhouse effect.

All that is needed is to add heat carried upwards past the denser atmosphere (and most CO2) by convection and the latent heat from water changing state (the majority of heat transport to the tropopause), the albedo effects of clouds, the inability of long wave «downwelling» (the blue balls) to warm water that makes up 2 / 3rds of the Earth's surface, and that due to huge differences in enthalpy dry air takes far less energy to warm than humid air so temperature is not a measure of atmospheric heat content.

Not exact matches

Among the most uncertain elements in climate models are the effects of aerosols and their interactions with clouds — just the things involved in albedo modification — she says.

They tend to believe that as the planet warms, low - level cloud cover will increase, thus increasing planetary albedo (overall reflectiveness of the Earth), offsetting the increased greenhouse effect and preventing a dangerous level of global warming from occurring.

The radiative effect of clouds on the shortwave fluxes is computed as a seasonally varying (but fixed from one year to the next) and spatially varying atmospheric albedo.

But they do at least have certain basic physical principles in their cloud representations — clouds over ice have less albedo effect than clouds over water, you don't get high clouds in regions of subsidence, stable boundary layers lead to marine stratus, 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.

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.

«By comparing the response of clouds and water vapor to ENSO forcing in nature with that in AMIP simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor feedbacks has revealed two common biases in the models: (1) an underestimate of the strength of the negative cloud albedo feedback and (2) an overestimate of the positive feedback from the greenhouse effect of water vapor.

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).

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.

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?

The bottom line is that uncertainties in the physics of aerosol effects (warming from black carbon, cooling from sulphates and nitrates, indirect effects on clouds, indirect effects on snow and ice albedo) and in the historical distributions, are really large (as acknowledged above).

The top panel shows the direct effects of the individual components, while the second panel attributes various indirect factors (associated with atmospheric chemistry, aerosol cloud interactions and albedo effects) and includes a model estimate of the «efficacy» of the forcing that depends on its spatial distribution.

The details of the physics of different forcings (i.e. ozone effects due to solar, snow albedo and cloud effects due to aerosols etc.) do vary the feedbacks slightly differently though.

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).

This is what I get out of it: the Arctic - ice - albedo situation is more complicated than earlier thought (due to clouds, sun - filled summers, dark winters, etc), but NET EFFECT, the ice loss and all these other related factors (some negative feedbacks) act as a positive feedback and enhance global warming.

The mechanism which they claim to have identified is actually the opposite of what Lindzen described, where he claimed that clouds would increase as the result of the greenhouse effect and their albedo effect would hold down temperatures, but in the tropics the clouds that Spencer et al were dealing with presumably become fewer in number.

If water (rain, clouds, oceans) is the stabilizer, then it should overwhelm any warming by trace gases, albedo effects of glacial advances and retreats, etc..

The impact of such an effect on the planetary cloud albedo has not been assessed.

The mechanism by which the effect of oceanic variability over time is transferred to the atmosphere involves evaporation, conduction, convection, clouds and rainfall the significance of which has to date been almost entirely ignored due to the absence of the necessary data especially as regards the effect of cloudiness changes on global albedo and thus the amount of solar energy able to enter the oceans.

i) Solar variability as regards the mix of particles and wavelengths appears to have an effect on the composition of the upper atmosphere which can then affect clouds and albedo in the way I have described elsewhere.

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).

I agree about the albedo effect of snow, but the way albedo is formed has been given some insights with the new Svensmark paper on cloud formations.

However, even a smaller figure (I had calculated about 0.17 W / m ^ 2 based on your inflated figure for total planetary albedo, but you can check it out) is still significant when compared with the total flux imbalance, which I think is a more informative comparison than an arbitrarily selected change in cloud cover, because it compares the sea ice reduction with the effects of all climate variations that have been operating in recent years..

From the figures I took an average value of 0.45 — but, hey, if you prefer to assume 0.35, that's OK, because it will not change the conclusion that the observed Arctic sea ice melt has not appreciably changed our planet's total albedo, and that a very small change in cloud cover would have a far greater effect.

Cloud variations are obviously an important element on a global scale, but the effects of Arctic ice melting are important locally and also a non-trivial fraction of global albedo feedbacks, which are a contributor to total feedback that is smaller than those from water vapor and probably from cloud feedbacks, but not insignifiCloud variations are obviously an important element on a global scale, but the effects of Arctic ice melting are important locally and also a non-trivial fraction of global albedo feedbacks, which are a contributor to total feedback that is smaller than those from water vapor and probably from cloud feedbacks, but not insignificloud feedbacks, but not insignificant.

Its warming effect, however, is simultaneously amplified and dampened by positive and negative feedbacks such as increased water vapor (the most powerful greenhouse gas), reduced albedo, which is a measure of Earth's reflectivity, changes in cloud characteristics, and CO2 exchanges with the ocean and terrestrial ecosystems.

He assumes a feedback of 1.6 for water vapor, 1.3 for clouds, and 1.1 for ice / albedo effects.

If not either the CO2 / temp relationship is wrong [I do not think so] or the effect of the CO2 rise is being variably effected by negative feedbacks such as increased cloud formation and albedo thus offsetting the CO2 related temperature rise.

However, I am not a «warmista» by any means — we do not know how to properly quantify the albedo of aerosols, including clouds, with their consequent negative feedback effects in any of the climate sensitivity models as yet — and all models in the ensemble used by the «warmistas» are indicating the sensitivities (to atmospheric CO2 increase) are too high, by factors ranging from 2 to 4: which could indicate that climate sensitivity to a doubling of current CO2 concentrations will be of the order of 1 degree C or less outside the equatorial regions (none or very little in the equatorial regions)- i.e. an outcome which will likely be beneficial to all of us.

The size and intensity of the polar vortexes then has an effect on the latitudinal position of the jetstreams which then alters total cloud quantities (and reflectance) so as to alter global albedo and thereby alter solar energy input to the oceans.

This being the case, a period of higher sunspot activity would likely lead to reduced lower tropospheric cloud cover (due to reduced albedo effect) and generally higher temperatures.

This being the case, a period of higher sunspot activity would likely lead to reduced lower tropospheric cloud cover (due to reduced albedo effect) and temperatures.

For example, AR4 WG1 assesses the level of scientific understanding of cloud albedo effects as «low.»

As such cloud variation, independent of temperature COULD be a significant independent variable, a true cause or forcing of the climate given the great GHG / albedo effect they have, perhaps it deserves greater investigation?

Heating «cloud albedo effect» is a far better explanation of palaeo - climate than CO2 because the latter has a delay of 500-1500 years as oceans warm.

That greenhouse gases being absent does not effect the one third of solar radiation being absorbed by clouds Or the surface albedo can jump from 12 % to 30 % Or the greenhouse gases being absent but still have clouds to reflect radiation Or the IR (not now absorbed) by the clouds will not obey Kirchoff's Law on reaching the planet surface And so on.

Greenhouse gas clouds lower the Albedo of the Earth resulting in a lower effective emission temperature — you shouldn't count the greenhouse effect of clouds and then not count the solar reflecting impact of the same clouds.

As the CO2 and CH4 (methane) level goes up, H2O vapour in the atmosphere falls which — because H2O is 30 times more important than CO2 as a «greenhouse gas» offsets the effect of CO2 on temperature, while cloud cover and albedo increases because warmed moist air rises to form clouds, further cooling the world.

``... underestimating the negative feedback from cloud albedo and overestimating the positive feedback from the greenhouse effect of water vapor over the tropical Pacific during ENSO is a prevalent problem of climate models.

Because the earth has clouds with behaviors, and atmos moisture is not uniform or constant, and surface albedo changes constantly, it is possible to have either or amplification or damping of the theoretical CO2 effect (or both via different processes).

So, CO2 - AGW is probably very low [overestimated by a factor of > = c. 3] and «cloud albedo effect» heating has probably been responsible for the warming, now stopped because the effect has has saturated.

When you compare this with the actual surface temperature of ~ 288 K and the temperature in absence of the greenhouse effect but no change in albedo of ~ 255 K, what we can say is the follows: The greenhouse effect due to all the greenhouse gases (water vapor, clouds, and the long - lived GHGs like CO2 and CH4) raises the temperature of the Earth by an amount of ~ 33 K (which is 288K — 255K); the albedo due to cloud reduces the temperature by ~ 17 K (which is 272 K — 255 K); the net effect of both the GHGs and the cloud albedo is ~ 16 K (which is 288K — 272K).

Had they applied reasonable physical models for the integrating and lagging (low pass filtering) response of the ocean, and the positive feedback of cloud albedo from the burn off effect, they could have discovered that solar activity can account for the full, 140 - year instrumented temperature record.

The spatial patterns of RFs for non-LLGHGs (ozone, aerosol direct and cloud albedo effects, and land use changes) have considerable uncertainties, in contrast to the relatively high confidence in that of the LLGHGs.

-- Incorporation of more aerosol species and improved treatment of aerosol - cloud interactions allow a best estimate of the cloud albedo effect.