Clouds

The tiny droplets of water or ice crystals are so small and light that they can float in the air, forming clouds.

A cloud is a large collection of very tiny droplets of water or ice crystals. The droplets are so small and light that they can float in the air. When billions of these droplets come together they become a visible cloud. Clouds and rain form a vital part of the water cycle.

All air contains water vapor, this is the result of evaporations of water from rivers, lakes and oceans. As the water vapor accumulate, it leads to the formation of clouds.

Clouds come in various shapes and forms. This one is dark and thick, meaning it is probably a rain cloud.

Clouds are usually white. As the white sunlight, which is made up of red, orange, yellow, green, blue, indigo, and violet, hits a cloud, the water vapor absorbs all the color evenly, which gives the cloud a white and fluffy appearance. 

If the clouds get thick enough, not all the light from above will make it through, resulting in a gray bottom.

The white light of sunlight is composed of all colors of the visible spectrum. Rainbow is another example of white light separating into a spectrum of colors.

Thin clouds scatter and reflect most of the incoming sunlight, which makes them white and translucent.

Thicker clouds absorb more of the light, making them darker and more opaque. 

A cloud will typically have a white top and a darker bottom, this is because the sun is usually shining above the clouds. 

The air around us contains plenty of water, in the form of tiny particles known as water vapor. When the water vapor condenses in the sky, clouds are formed. 

Clouds that become dense enough will release precipitation, usually rain or snow, when the water vapor becomes too heavy or dense to float.

Surface water evaporates from oceans and lakes turning into water vapor in the air.

As the warm, moist air rises, it cools due to the colder air at higher altitude. The condensation process forms a visible cloud.

While the cloud itself cannot move, wind carries the cloud. Temperature or pressure change can also cause cloud to rise or sink.

Tiny droplets inside of clouds join together to form larger drops. Eventually, when thousands of the droplets combine, the drops may become large enough to fall to the ground as rain.

Clouds take on very different characteristics at different latitudes.

The characteristics of clouds are dictated by climate conditions including the amount of water vapor in the air, the temperatures, and the speed of the winds, as well as the interplay of other air masses.

At high latitude locations, the air is cold, and it doesn’t hold a lot of moisture. In these areas, the sky often tends to be clear and free of clouds.

Many different types of clouds form depending on the climate and landscape.

Near the equator, the air is warm and very humid. Large rain-clouds form and dissipate quickly. Thunderstorms are also common.

Clouds come in many different shapes. Many factors contribute to their variety, including altitude, wind, and air temperature. 

The water vapor and ice crystals often form into certain recognizable types that can tell us about their density, origin, and what the conditions are in the atmosphere.

Cirrus clouds are high level clouds that are thin and wispy. They appear during good weather. Because of the high altitude, cirrus clouds are mostly made up of ice crystals.

Cirrocumulus clouds are high clouds that look like tiny cotton balls bunched together.

Stratus clouds are low level clouds that are flat and tend to cover much of the sky. They are gray in color and sometimes may produce light rain or drizzle.

Cumulus clouds are low to mid-level clouds. They are big, white, puffy, and beautiful clouds. They usually mean good weather unless they grow really tall and turn into cumulonimbus clouds, which bring rain, thunder, and lightning.

Occasionally, very odd looking clouds will form due to a combination of rare or unique circumstances. Sometimes they are formations left behind by human activity. They may look strange, but they are still clouds because they still contain water vapor.

Lenticular clouds are caused by a wave wind pattern that is created by the mountains. These stationary clouds that look like lenses, discs, or flying saucers are most often seen near mountains.

Fog is actually a stratus cloud very close to or even touching the ground. Fog exists if the atmospheric visibility near the Earth's surface is reduced to 1 kilometer or less.

Contrails are condensation trails left behind by jet aircraft. When hot, humid jet engine exhaust air meets dry and cold temperatures in the high altitude atmosphere of flight, contrails appear.

Normally we can’t see much when we are inside a cloud. But if we shrink down to the size of a molecule, then we’ll be able to see individual water molecules and nuclei. We will see mostly H2O, two atoms of hydrogen and one of oxygen.

The red sphere is the Oxygen atom, the two white spheres are Hydrogen atoms. Two hydrogen atoms and an oxygen atom make up a water molecule.

A nucleus is any particle that water vapor can stick to for condensation to happen. It could be a piece of dust, a grain of pollen, or a particle of salt.