Sentences with phrase «cloud albedo decreases»

For instance, Han et al. (1998) showed that cloud albedo decreases with decreasing droplet size for the optically thinner clouds over the oceans.

Not exact matches

[Response: weaker cosmic ray flux - > fewer low clouds - > decrease in sunlight reflected back to space), then you need to explain why the night temperatures appear to increase faster then day temperatures (for any amplification mechanism involving te albedo, you'd expect the opposite, as there is no sunlight to reflect on the dark side of the planet...).

Unless low - level cloud albedo substantially decreased during this time period, the reduced solar absorption caused by the reported enhancement of cloud cover would have resulted in cooling of the climate system that is inconsistent with the observed temperature record.»

According to the skeptics, the solar irradiance isn't very important, it is the strength of the sun's magnetic field (that allows or stops cosmic rays from coming in which then causes more or less clouds, which increases or decreases the Earth's albedo, which then causes warming or cooling of the Earth's surface).

On the possibility of a changing cloud cover «forcing» global warming in recent times (assuming we can just ignore the CO2 physics and current literature on feedbacks, since I don't see a contradiction between an internal radiative forcing and positive feedbacks), one would have to explain a few things, like why the diurnal temperature gradient would decrease with a planet being warmed by decreased albedo... why the stratosphere should cool... why winters should warm faster than summers... essentially the same questions that come with the cosmic ray hypothesis.

He goes on to claim that «Pollution increases the albedo of thin clouds because but, contrary to the present theory, decreases it for thick clouds.

Here's an example of your general illogic: Suppose we had a time period in which the planet's albedo decreased (fewer clouds or aerosols, let's say) but the average surface temperature of the planet also decreased.

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 implies that the CRF levels must have systematically decreased over time, causing a long - term decrease in the low cloud fraction and hence a long - term reduction in the planetary albedo, that again would be responsible for the warming.

It's looking more and more like most climate change can be pegged to changes in solar output, either directly through additional warming or indirectly as decreases in solar output allow more cosmic rays to reach the atmosphere, causing increased cloud nucleation and therefore increasing the earth's albedo and reflecting more solar radiation.

Albedo from medium / low level clouds warms or cools the ocean surface by increasing or decreasing over time across the global surface.

Increased warming - > increased evaporation - > increased clouds - > increased albedo - > decreased solar input.

SWR easily explains the changes when this penetrates down to 100m depth compared with 0.5 mm while cloud albedo had decreased.

Again, I do not see much to get excited about here, particularly when considering that the albedo increase from a 1 % increase in cloud cover would more than offset this decrease.

A 0.2 % decrease in albedo could come from, among other things, fewer clouds or less snowcover or black carbon accumulation on existing snowcover.

(1) The uptick in DTR may be simply explained by the decrease in cloudiness (and albedo) observed between 1981 and 1999 according to the international cloud project data.

«The uptick in DTR may be simply explained by the decrease in cloudiness (and albedo) observed between 1981 and 1999 according to the international cloud project data.

Reduced OLR and / or decreasing albedo (clouds, snow and ice) are the only two candidates.

We had the warm ENSO period of the 1980s / 1990s (which led to the all - time record warm year 1998), an observed decrease in late 20th C cloud cover (and albedo), the highest solar activity for several thousand years, etc..

Project Earthshine (Earthshine is the ghostly glow of the dark side of the Moon) has been measuring changes of the terrestrial albedo in relation to cloud coverage data; according to cloud coverage data available since 1983, the albedo of the Earth has decreased from 1984 to 1998, then increased up to 2004 in sync with the Mean Global Temperature.

And, even this number is in some sense deceiving because increasing clouds actually has two effects: a cooling effect due to the increase in albedo and a warming effect due to a decrease in the outgoing IR («longwave») radiation.

The latter effect acts to reduce CO2 sensitivity by increasing the aerosol - sensitive SW tau, increasing both cloud density and cover, decreasing upper tropospheric specific humidity and INCREASING SW albedo and will increasingly do so as the atmospheric level of CO2 rises!

Another issue is the potential for light - absorbing aerosols to increase in - cloud absorption of solar radiation and correspondingly decrease the cloud albedo when incorporated inside cloud droplets.

The latter effect acts to reduce CO2 sensitivity by increasing the aerosol - sensitive SW tau, increasing both cloud density and cover, decreasing upper tropospheric specific humidity and SW albedo and will increasingly do so as the atmospheric level of CO2 rises!

High sensitivity is caused by increasing water vapour as the tropopause rises and diminishing low cloud cover, but the sensitivity decreases for still larger CO2 as cloud optical thickness and planetary albedo increase, as shown by Russell et al. [112].

Palle et al (cited elsewhere here) have shown that the total albedo has decreased over the period 1985 - 2000, while cloud cover also decreased (resulting in global warming), and has reversed itself since then, with increased cloud cover.

A drying of the atmosphere — that the researchers note — takes place in the subtropical subsidence zone (the 30 degrees latitude) but expands towards the 30 - 45 degrees latitude — Earth's Meditteranean climates, where their model suggests net cloud cover would actually decrease most (see dotted line in first image in this article, at top)-- most notably around 500 hPa (roughly translating to a height of around 5 kilometers of altitude in the troposphere) decreasing albedo and increasing solar heat absorption, therefore net climate warming.

The main cloud bands move more poleward to regions where solar insolation is less intense so total global albedo decreases.

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).

Putting the two formulas together, a theoretical additional factor of 2.06 multiplier due to the greenhouse effect becomes an actual multiplier of 0.226, thanks to negative factors like increases in albedo due to clouds, decreases in lapse rate, etc..

Snowfall and clouds are now sufficient to stop the Ice Extent from decreasing and sufficient to stop the Albedo from decreasing.

And if this type of albedo were to decrease, would that decrease outweigh albedo increases, say, due to clouds or other factors?

It is logical to presume that changes in Earth's albedo are due to increases and decreases in low cloud cover, which in turn is related to the climate change that we have observed during the 20th Century, including the present global cooling.

Unless low - level cloud albedo substantially decreased during this time period, the reduced solar absorption caused by the reported enhancement of cloud cover would have resulted in cooling of the climate system that is inconsistent with the observed temperature record.»

Cloud amount and albedo decreased over mid-latitude oceans in both hemispheres (especially over the North Atlantic), over the southeast Indian Ocean, and in a northwest - to - southeast line stretching across the central tropical South Pacific.»