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Rothiemurchus
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Are clouds held in the air by archimedes principle or by rising heat or something else?
Not quite. Clouds do float and the effect is buoyancy.Strictly speaking clouds don't float ( they aren't boyant in air ),
This is true.Thermal motion of all the air molecules hitting the water droplets at random stops them settling out
http://asd-www.larc.nasa.gov/edu_act/clouds.htmlThe most common ways to lift a parcel of air are: buoyancy, topographic lifting, and convergence. Buoyant lifting results from surface heating. This is a common manner of cloud formation in the summer. Buoyancy lifting is also called convection and occurs when local warm areas heat the air near the surface (fig 31a). The warm air is less dense than the surrounding air and rises. This rising air will eventually cool to its dew point and form a fair-weather cumulus cloud.
mgb_phys said:Strictly speaking clouds don't float ( they aren't boyant in air ), there are 2 mechanisms keeping them up;
Astronuc said:Not quite. Clouds do float and the effect is buoyancy.
mathman said:This may be oversimplifying, but water (mol.wt.=18) molecules are lighter than oxygen (32) or nitrogen (28) molecules.
BillJx said:What I always find fascinating is the sharpness of the air interfaces - - the flat bottoms of clouds, the razor-straight frost line on a hillside, the horizontal layer of smoke in a bar etc. I don't really get why the layers are so sharply separated.
BillJx said:the razor-straight frost line on a hillside
Clouds stay afloat in the air due to a combination of factors, including the temperature, air pressure, and water cycle. As warm, moist air rises, it cools and condenses to form clouds. The air pressure at higher altitudes is lower, which helps keep the lighter water droplets suspended in the air.
While it may appear that clouds are falling from the sky during rain or snow, it is actually the water droplets and ice crystals within the clouds that are falling. These droplets and crystals are too small and light to maintain their position in the air, so they eventually fall to the ground as precipitation.
No, clouds require a specific combination of temperature, pressure, and water vapor to form and stay suspended in the air. They are typically made up of water droplets or ice crystals and cannot float on other gases such as carbon dioxide or nitrogen.
The movement of clouds is influenced by wind patterns in the atmosphere. Stronger winds can cause clouds to move more quickly, while weaker winds may cause them to appear to move more slowly. The shape and size of the clouds can also impact their perceived speed.
The lifespan of a cloud can vary depending on its size, location, and atmospheric conditions. Some clouds may only last a few minutes, while others can persist for several hours. In general, once the temperature and pressure conditions change, the water droplets or ice crystals making up a cloud will eventually dissipate, causing the cloud to disappear.