How do clouds float in the sky???

Question

Clouds are made of water vapour which freezes at 0 degree celcius

the temperature in the sky is well below 0 degrees hench why planes have to be pressurized (or they wil freeze)

so how on earth do the clouds both stay gaseous (so planes can pass through them) and float in the sky (rather than falling)????

thanks

Answer 1

It is made up of dust. Right. So it acts as dust floating and moving from another place.

Answer 2

How Clouds Work

http://science.howstuffworks.com/cloud.h...

As water molecules shift between vapor, liquid and solid phases, they move throughout the air, even if we can't see them. However, when a parcel of air cools quickly and reaches saturation, there's a chance water vapor will condense and appear as a cloud. This could occur because of different factors, like the terrain pushing it upwards into cooler air (called orographic lifting), or perhaps, because it enters a cold front.

Additionally, cloud formation happens easily when water vapor has something to cling to, allowing the water vapor to change into its liquid or solid phases. A number of particles can act in this function. Commonly called condensation nuclei or freezing nuclei (also known as aerosols or nucleators), the name pretty much says it all if you know about atoms. Typically, things like dust particles, sea salt particles and soot from wildfires will serve as nucleators, and the water droplets or ice crystals form around them. Studies show that bacteria -- specifically certain plant bacteria -- can also serve as the focal point for condensation.

Clouds are, in essence, massive collections of tiny water droplets and crystallized water molecules. The different shapes, textures and other features of clouds depend largely on the conditions under which they form and later develop. For instance, temperature, humidity and altitude are all factors that affect cloud formation.

But how do clouds move and eventually disappear? The difference between air within a cloud and the air surrounding it dictates cloud movement. For example, frontal wedging occurs when a cloud that's part of a warmer air mass encounters a colder air mass. The warmer parcel will likely be forced up, over the cold mass. When this happens, rain usually occurs along the front edge of that meeting point.

This leads us to how clouds dissipate, or more accurately, evolve. Usually, clouds just change from one type to another. Using the previous example, the front where both masses meet could cause drifting cumulus clouds to change into a line of nimbostratus clouds (delivering precipitation). As the warm air continues to rise, those clouds could evolve into altostratus clouds, then cirrostratus clouds, and finally into cirrus clouds. As the weather pattern progresses, the air mass might reach a point where the clouds dissipate. It's only a matter of time before that water vapor joins another cloud, and the process begins again.

Answer 3

look up Brownian motion.

air temps in the sky are not always freezing, but that's not why planes need to be pressurized. it's pressurized so passengers don't suffocate since there's 25-50% of the normal oxygen up there.

Answer 4

Clouds are made of either very tiny water droplets or ice crystals, depending on the temperature of the air where they formed.  The temperature of the air does typically cool as you increase in altitude, but the freezing level (where the air reaches 0 degrees C) varies in height.  Water can exist in liquid form at a temperature below freezing (known as supercooled water), and in fact this is when aircraft icing becomes a problem, because the small supercooled water droplets freeze instantly upon contact with a sub-freezing surface.

The clouds remain in the sky because they are composed of such small water droplets that the upward motion in the air that lead to them forming in the first place is enough to keep the tiny droplets (or ice crystals) suspended in the air.

Answer 5

Clouds are not water vapor, they are tiny water droplets (or ice).  Water vapor, the gaseous form of water in the atmosphere and measured by humidity, is actually invisible.  When water vapor condenses back into liquid water in the air we see a cloud.  If the droplets get big enough it falls as rain.

Clouds don't always float in the sky.  They are affected by gravity as any matter is.  But there are other forces that counteract that gravity and keep clouds in the sky - Usually.  Fog, for example, is just a cloud close to the ground.   There are a couple of reason Clouds 'float' in the sky.

1,  The water droplets are so tiny, any rising air current pushes them up.

2.  When cloud droplets do fall and go from cooler air to warmer air they often turn back into water vapor - and the cloud dissipates below a certain altitude.  Pilots call this the 'ceiling'.  Above it you have visible moisture (clouds) below it there are no clouds.  The altitude of the ceiling depends on temperature and moisture content of the air, so it varies day to day, place to place.