Sentences with phrase «temperature effects of cloud»

The temperature effects of cloud cover during the 20th century could be as much as 7 times greater than the alleged temperature effect of 200 years worth of additional carbon dioxide and several times greater than that of all additional greenhouse gases combined.

Not exact matches

In the case of a nearby super nova the effect can be more than 50 % of the growth rate, which will have an impact on the clouds and the Earth's temperature.

Despite its smaller ash cloud, El Chichn emitted more than 40 times the volume of sulfur - rich gases produced by Mt. St. Helens, which revealed that the formation of atmospheric sulfur aerosols has a more substantial effect on global temperatures than simply the volume of ash produced during an eruption.

For a subset of 14 relatively clear (cloudy) stations, the mean temperature drop was 0.91 ± 0.78 (0.31 ± 0.40) degrees C, but the mean temperature drops for relatively calm and windy stations were almost identical, indicating that cloud cover has a much greater effect than wind on the air temperature's response to an eclipse.

They found a small correlation between cosmic rays and global temperatures occurring every 22 years; however, the changing cosmic ray rate lagged behind the change in temperatures by between one and two years, suggesting that the cause of the temperature rise might not be attributable to cosmic rays and cloud formation, but could be caused by the direct effects of the sun.

When the CLIMAP data proved to be wrong, and was replaced by more reliable estimates showing a substantial tropical surface temperature drop, Lindzen had to abandon his then - current model and move on to other forms of mischief (first the «cumulus drying» negative water vapor feedback mechanism, since abandoned, and now the «Iris» effect cloud feedback mechanism).

There is a clear impact on global temperature, too, though the mechanisms are complex: heat released from the oceans; increases in water vapor, which enhance the greenhouse effect, and redistributions of clouds.

And as this knowledge is disseminated and better understood, eventually we'll have better models, and can achieve more widespread adoption of them - if the solar / cosmic ray / cloud mechanism is significant it could explain why temperatures in neither hemisphere are proceeding upwards lock - step with IPCC forecasts - and opening the door for a more accurate and widespread acknowledgement of CO2 effects on temperature and climate.

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.

While on the subject: Could I ask your take on Erlykin et al. 2011, in particular their finding that any effect of cosmic radiation is limited to 1 % of cloud cover, and their estimate that any temperature increase due to such a mechanism over the past 50 years of barely changing CR is limited to 0.002 °C?

For cause and effect: You never know, but I don't think that cloud cover regulates the sun cycle... Globally, the variation of cloud cover during a sun cycle is around 2 %, which can have a substantial influence on global temperatures.

By the way, low clouds in darkness increase surface temperature, sort of like the inverse property of commonly understood Cosmic ray effect, not causing a cooling because there are more CR's, but rather a warming, which only low clouds in total darkness can do, so the probable CR temperature signal gets cancelled from one latitude dark vs bright region to the next.

It's possible that CO2 contributes about a.6 C increase in temperature and that the effects of clouds acts as a negative feedback to moderate further increases.

The paper he wrote together with Friis - Christensen in which he found a correlation between solar activity and clouds had a «slight» flaw: it ignored that the period of the study coincided with a big El Nino, and that large scale changes in ocean surface temperature are going to have an effect on cloud formation.

I would suggest comparing peak to peak average temperature captures during weighted El - Nino events (during the time they occur, if they can be compared equally this would be a telling graph), instead of considering year to year records as a means of reducing ENSO effects on the temperature record, ENSO being largely a heat exchange between air and sea causing great changes in cloud distribution world wide.

There are three types of mechanisms that conspire to give a cloud it's id: dynamical (air movements), thermodynamical (temperature / humidity conditions) and microphysical (droplet collisions, aerosol effects.

# 27 CCPO It's possible that CO2 contributes about a.6 C increase in temperature and that the effects of clouds acts as a negative feedback to moderate further increases.

Just two remarks: you keep on saying that the effect of increased cloudiness «should be warming», whereas the data shown in the article clearly show the opposite (more clouds cause lower surface level air temperatures).

Unknown is what the overall effect of greenhouse gases / temperature was / is / will be on cloud cover.

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).

When the CLIMAP data proved to be wrong, and was replaced by more reliable estimates showing a substantial tropical surface temperature drop, Lindzen had to abandon his then - current model and move on to other forms of mischief (first the «cumulus drying» negative water vapor feedback mechanism, since abandoned, and now the «Iris» effect cloud feedback mechanism).

There will be Regionally / locally and temporal variations; increased temperature and backradiation tend to reduce the diurnal temperature cycle on land, though regional variations in cloud feedbacks and water vapor could cause some regions to have the opposite effect; changes in surface moisture and humidity also changes the amount of convective cooling that can occur for the same temperature distribution.

First, for changing just CO2 forcing (or CH4, etc, or for a non-GHE forcing, such as a change in incident solar radiation, volcanic aerosols, etc.), there will be other GHE radiative «forcings» (feedbacks, though in the context of measuring their radiative effect, they can be described as having radiative forcings of x W / m2 per change in surface T), such as water vapor feedback, LW cloud feedback, and also, because GHE depends on the vertical temperature distribution, the lapse rate feedback (this generally refers to the tropospheric lapse rate, though changes in the position of the tropopause and changes in the stratospheric temperature could also be considered lapse - rate feedbacks for forcing at TOA; forcing at the tropopause with stratospheric adjustment takes some of that into account; sensitivity to forcing at the tropopause with stratospheric adjustment will generally be different from sensitivity to forcing without stratospheric adjustment and both will generally be different from forcing at TOA before stratospheric adjustment; forcing at TOA after stratospehric adjustment is identical to forcing at the tropopause after stratospheric adjustment).

There can / will be local and regional, latitudinal, diurnal and seasonal, and internal variability - related deviations to the pattern (in temperature and in optical properties (LW and SW) from components (water vapor, clouds, snow, etc.) that vary with weather and climate), but the global average effect is at least somewhat constrained by the global average vertical distribution of solar heating, which requires the equilibrium net convective + LW fluxes, in the global average, to be sizable and upward at all levels from the surface to TOA, thus tending to limit the extent and magnitude of inversions.)

This elegant, self - regulatory, atmospheric mechanism was soon attacked for being based on limited data and the inability of other researchers to identify the effect in other cloud and temperature data sets.

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.

A Lacis: You don't seem to appreciate the fact that water vapor and clouds are feedback effects, which means that the water vapor and cloud distributions depend directly on the local meteorological conditions, and are therefore constrained by the temperature dependence of the Clausius - Clapeyron relation.

You don't seem to appreciate the fact that water vapor and clouds are feedback effects, which means that the water vapor and cloud distributions depend directly on the local meteorological conditions, and are therefore constrained by the temperature dependence of the Clausius - Clapeyron relation.

So with the «greenhouse gas effect» if I add more CO2 AND all other things remain equal, temperature will increase, but if clouds are a regulating mechanism, adding more CO2 doesn't have to change temperature at all, just the amount of energy required to maintain that temperature would be reduced.

I write it off as a very real effect that is not well characterized by the models, probably because these models don't model with enough accuracy the effect of the additional aerosol particles on cloud production to properly account for it's full effect on temperature.

These models suggest that if the net effect of ocean circulation, water vapour, cloud, and snow feedbacks were zero, the approximate temperature response to a doubling of carbon dioxide from pre-industrial levels would be a 1oC warming.

Modelers have chosen to compensate their widely varying estimates of climate sensitivity by adopting cloud feedback values countering the effect of climate sensitivity, thus keeping the final estimate of temperature rise due to doubling within limits preset in their minds.

What Willis is describing is that vulcanism can effect air temperature and clouds, the changed air temperature subtly changes the diurnal timing of cloud formation and that changes the rate of thermal charge accumulating in the oceans which ultimately is discharged in an El Niño.

I propose a simple dependence of cloud cover and water vapor greenhouse effect on incident solar radiance which can maintains temperatures to 0.5 degrees over the last 4 billion years.

If ∆ T = λ ∆ Q is a reasonable approximation of the (large - scale) effects of forcing on globally averaged temperature, why does it matter if a few clouds are banging around locally on a given day?

Going forwards CO2 forcing is several times larger than the LIA solar forcing which was itself measurable in the surface temperature record, so we expect CO2 forcing to be measurable for sure, and yes, it will be accompanied by some effects of changing clouds too, but we don't know which direction they would push it.

The net effect of clouds is cooling as is demonstrated by largely cloudless deserts having higher mean annual temperatures than moist climates at the same latitude.

Dr. Avakyan's paper attributes the known temperature rise to the effect of solar geomagnetic activity on clouds, and the known rise of CO2 to the carbon not absorbed due to expanding deforestation, desertification, and urbanization, and the resulting lessening of photosynthesis.

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.

I have heard that global climate models have very rudimentary cloud models and do not include such effects of solar / cosmic rays nor of the correlation with earth's Length of Day (as impacted by temperature and wind changes).

The physics of cloud formation, the Clausius - Clapeyron relation, and elementary observations dictate that cloud cover will increase with increasing surface temperature, notwithstanding short term, non-climate or regional effects like ENSO oscillations.

One important feedback, which is thought to approximately double the direct heating effect of carbon dioxide, involves water vapor, clouds and temperature.

Clouds are one of the big unknowns about global warming as they can have a range of effects, warmer temperatures caused by global warming will result in higher rates of evaporation and therefore will result in higher cloud cover.

If cloud cover can vary as noted per the paper, and just a few percent change in cloud cover can have a large effect to temperatures, then how much confidence can one have in the «CO2 is the greatest driver of increased temperatures?

A traditional parametrisation scheme seeks to represent the average effect of the sub grid - scale motion (e.g. convective clouds) on the resolved scale state (e.g. the large scale temperature and wind fields).

Meanwhile it does not answer the main point of my last post, which is that that most climatologists view this aspect of the earth's environment as «weather» (or statistical noise) and that if you measure temperatures for long enough periods of time (30 + years) the effect of clouds, rain and water vapour average out and a temperature trend signal will become apparent.

More clouds both drastically reduce energy input from the sun and simply slow release of what energy there is trapped in the lower troposphere, but the long term effect would be a fall in average temperature because of the significantly reduced input power but the atmosphere's ability to cool is aided by air current circulation whereby the warmer air rises above those low clouds and that infra - red is more easily re-emitted into space, whereby the low clouds now block that re-emission from hitting the ground again to any significant degree.

These include the effects that trees have on local atmospheric chemistry and potentially the clouds above them; until these are fully understood it is somewhat difficult to attribute a «temperature benefit» of a specific magnitude to a given afforestation scenario.

Excerpt: -LSB-...] «We have recently submitted to Journal of Geophysical Research a research paper that shows how one can tell the difference between cause and effect — between clouds causing a temperature change, and temperature causing a cloud change.

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.