Sentences with phrase «changes in cloud cover»

This might cause changes in cloud cover, due to consequent reductions in relative humidity, so you have to stop those too because they are a feedback.

The potential for changes in cloud cover as a result of the changes in sea ice makes the evaluation of the actual forcing that may be realized quite uncertain, since such changes could overwhelm the forcing caused by the sea - ice loss itself, if the cloudi - ness increases in the summertime.

Even if Earth truly were a flat disk without terrain, and even if the energy transfer processes were linear, and even if the system were in steady - state, the models would not be accurate enough to make a long - term forecast of the effects of doubling CO2 because the models can not even predict changes in cloud cover.

Berkeley Lab researchers Dev Millstein and Surabi Menon found that atmospheric feedback — such as changes in cloud cover or precipitation — does have an important effect, resulting in different amounts of cooling in different cities, but that cool roofs and pavements are still beneficial for combating global warming.

Rather than look directly for changes in cloud cover we examined the better quality records of the daily temperature range.

Several mechanisms have been hypothesized to explain this reduced temperature gradient, including increased poleward heat transport, decreased ice albedo, and changes in cloud cover (Fedorov et al., 2006).

These changes in cloud cover could affect how much of the sun's radiation is reflected by the clouds, leading to a slightly warmer planet, the scientists said.

On reading the paper there are several references to a planetary influence on the Earth's magnetosphere and how increased cosmic flux excites the outer atmosphere leading ultimately to more mid-latitude auroras (and changes in cloud cover).

For a good example of science denial check out Bob Droege, who asserts that changes in cloud cover can't affect surface temperature.

A larger set of arrays in Mobile is tracking the effect of heat and humidity on solar production, and power pole - mounted panels in various locations are feeding energy to the grid in an experiment to gauge the effects of frequent changes in cloud cover.

If this hypothesis is validated it could be a «paradigm buster», in that it would provide a mechanism for the observed reaction of our climate to changes in cloud cover (Spencer) and the empirically observed correlation between solar activity and temperature (Svensmark), which lies beyond the measured impact of direct solar irradiance alone.

The main agent of climate change has been abandoned for many decades, the unanswered question of the drivers of ENSO and the AMO, and the changes in cloud cover and changes in the vertical distribution of water vapour that they drive.

Spencer has postulated elsewhere that natural factors, such as PDO swings, might be the underlying cause for changes in cloud cover, which result in changes in global temperature, IOW that clouds act as part of a natural forcing, rather than simply a feedback to anthropogenic (or other) forcing.

That increased atmospheric water vapor will also affect cloud cover, though impacts of changes in cloud cover on climate sensitivity are much more uncertain.

Other studies have indicated that synoptic scale changes in cloud cover are more likely correlated with regional climatological modes or oscillations rather than GCRs (Laken et al. 2012a).

Furthermore, although not in direct relation to the solar - cloud studies, Brest et al. (1997) state that the ISCCP data are not sensitive enough to detect small changes in cloud cover over long timescales.

(2) Alternatively, FD events might only result in dynamic effects over winter cyclogenesis regions, and therefore may not necessarily produce direct changes in cloud cover (Tinsley & Deen 1991).

So you get a little attribution here, a little there, you dance around the effects of changes in cloud cover, and the whole thing never forms a cohesive whole.

Using 13 yr of satellite observations for the Tibetan Plateau, the sensitivities (or partial derivatives) of daytime surface downward shortwave and longwave fluxes with respect to changes in cloud cover and cloud optical thickness are investigated and quantified.

On average, at all stations, the sensitivity of surface shortwave flux to changes in cloud cover is about -0.5 ± 0.1 W m - 2 % -1 in winter according to both ground - based and satellite observations but in summer reaches -1.5 ± 0.3 and -1.8 ± 0.2 W m - 2 % -1 according to ground - based and satellite observations, respectively.

Changes in cloud cover do not offer an explanation for a cooling stratosphere.

Again I want to emphasize that my use of the temperature change rate, rather than temperature, as the predicted variable is based upon the expectation that these natural modes of climate variability represent forcing mechanisms — I believe through changes in cloud cover — which then cause a lagged temperature response.This is what Anthony and I are showing here:

The downward shortwave flux is found to be modulated primarily by changes in cloud cover, but changes in optical thickness also have an impact, as revealed by a multiple regression fit.

«GeoFlynx says: June 8, 2010 at 11:45 am Changes in cloud cover do not offer an explanation for a cooling stratosphere.

To me, the prime suspect behind any real warming is changes in cloud cover which may have reduced albedo and may have allowed the oceans to absorb more solar energy.

New paper finds changes in cloud cover caused global brightening & dimming, not man - made aerosols

However, there have been several studies comparing observed changes in cloud cover to cloud simulations in climate models.

The GWPF report also notes that changes in cloud cover in a warming world are a key to determining climate sensitivity.

The idea is, if the change in surface temperature over that period is affected by changes in cloud cover, but changes of the surface temperature associated with the ocean warming are small, then changes in cloud cover must be driving the present global warming.

In short, the «skeptic» hypothesis that changes in cloud cover due to internal variability are driving global warming does not hold up when compared to the observational data.

But when they discussed changes in cloud cover, they mentioned that they couldn't tell from their data whether Spencer and Braswell's thesis about cause and effect applied.

Relatively small changes in cloud cover and its distribution could do this, for example.

I say my conclusion was «not unreasonable» because Dr. Scafetta, in a posting at WattsUpWithThat today, has also concluded that, once the natural 60 - year cycles of the great ocean oscillations are accounted for (and it may be these cycles that express themselves in changes in cloud cover such as that which Dr. Pinker had identified), the anthropogenic component in global warming is considerably less than the IPCC imagines.

The impact of these changes in cloud cover can account for the variations in HadCRUT4 global average temperature anomalies and the divergence between land and sea temperatures.

However, Lindzen's analysis of the experimental data suggests that «negative feedbacks» (e.g., changes in cloud cover) act to decrease the amount of warming from increases in CO2.

These include solar - related chemical - based UV irradiance - related variations in stratospheric temperatures and galactic cosmic ray - related changes in cloud cover and surface temperatures, as well as ocean oscillations, such as the Pacific Decadal Oscillation and the North Atlantic Oscillation that significant affect the climate.

Henrik Svensmark and others have shown a long - term correlation between solar activity and global temperature and have hypothesized that this results from changes in galactic cosmic rays leading to changes in cloud cover.

However, while Spencer hypothesizes that the changes in cloud cover are the main driver behind global warming, Dessler concludes that they're only responsible for a small percentage of the changes in surface temperature from 2000 to 2010.

via changes in cloud cover, ice cover, atmospheric aerosols concentrations and distributions) is incomplete and contains uncertainties on the order of the estimates of the forcing changes themselves. . .

Another potential contributor to amplified warming that's investigated is changes in cloud cover.

The satellite data shows that changes in cloud cover was the cause of all recent warming.

... Conclusions Since 1950, global average temperature anomalies have been driven firstly, from 1950 to 1987, by a sustained shift in ENSO conditions, by reductions in total cloud cover (1987 to late 1990s) and then a shift from low cloud to mid and high - level cloud, with both changes in cloud cover being very widespread.

While Spencer hypothesizes that the changes in cloud cover are the main driver behind global warming, Dessler concludes that they're only responsible for a small percentage of the changes in surface temperature from 2000 to 2010.

What will happen if the AO changes is an open question, at one side there may be less inflow of warmer air, at the other side, this may result in opposite changes in cloud cover...

This is true for negative (blue) and positive (red) «first order derivative» changes in cloud cover anomalies — note the areas northeast of the coast of Brazil and north of Australia.

No matter what (unknown) physical process causes the changes in cloud cover, these changes are observed during a sun cycle.

Further, the sun cycle induces relative large changes in cloud cover in the US, see: http://www.gsfc.nasa.gov/topstory/20010712cloudcover.html

The paper argues that climate sensititvity to CO2 is much lower according to «observation» and that simplified «models» combining PDO and CO2 can «explain» most of 20th century warming through PDO - induced changes in cloud cover.

It should be pointed out here, that the amount of change in downward heat radiation from changes in cloud cover in the experiment, are far greater than the gradual change in warming provided by human greenhouse gas emissions, but the relationship was nevertheless established.

Obviously it's not possible to manipulate the concentration of CO2 in the air in order to carry out real world experiments, but natural changes in cloud cover provide an opportunity to test the principle.