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Cloud albedo is a measure of the albedo or reflectivity of a cloud. Clouds regulate the amount of solar radiation absorbed by a planet and its solar surface irradiance . Generally, increased cloud cover correlates to a higher albedo and a lower absorption of solar energy .
Albedo (/ æ l ˈ b iː d oʊ / al-BEE-doh; from Latin albedo 'whiteness') is the fraction of sunlight that is diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects all incident radiation).
Cloud cover values only vary by 3% from year-to-year averages, whereas the local, day-to-day variability in cloud amounts typically rises to 30% over the globe. Land is generally covered by 10-15% less cloud than the oceans, because the seas are covered with water, allowing for more evaporation .
Changes of 3–4% in cloudiness and concurrent changes in cloud top temperatures correlated to the 11 and 22-year solar (sunspot) cycles, with increased GCR levels during "antiparallel" cycles. [96] Global average cloud cover change was measured at 1.5–2%.
In most models of "Snowball Earth", parts of the tropics were at least intermittently free of ice cover. As the ice advanced or retreated, climate sensitivity must have been very high, as the large changes in area of ice cover would have made for a very strong ice–albedo feedback. Volcanic atmospheric composition changes are thought to have ...
The interaction between cloud formation and climate change is an aspect of atmospheric science. Clouds have a dual role [6] in the Earth's climate system: they can cool the Earth's surface by reflecting incoming solar radiation (albedo effect) and warm it by trapping outgoing infrared radiation (greenhouse effect).
[7]: 95 The tropical high-cloud amount feedback is the main remaining area for improvement. The only way total cloud feedback may still be slightly negative is if either this feedback, or the optical depth feedback in the Southern Ocean clouds is suddenly found to be "extremely large"; the probability of that is considered to be below 10%.
Earthshine is used to help determine the current albedo of Earth. The data are used to analyze global cloud cover, a climate factor. Oceans reflect the least amount of light, roughly 10%. Land reflects 10–25% of sunlight, and clouds reflect around 50%.