CLOUDS 

What are the clouds exactly?

A cloud is an aerosol consisting of a visible mass of minute liquid droplets, ice crystals, or other particles suspended in the atmosphere of a planetary body or comparable space, according to meteorology.

What causes clouds to form?

When warm, wet air rises and cools, it forms a cloud. Why? Moisture is constantly present in the air. When the sun shines and the temperature rises, puddles, rivers, and the sea evaporate, releasing moisture into the air. When compared to warm air, cool air may contain less moisture. As a result, when warm air containing a lot of moisture cools down, the moisture condenses into little cloud droplets in the air. As it climbs, the air becomes cooler. Because the pressure is lower higher up in the sky, the air expands and cools as it expands. As a result, when moist air rises in the atmosphere, part of the water vapour condenses and forms small cloud droplets.

What causes certain clouds to be grey and others to be white?

Because little white cumulus clouds (fair weather clouds) have little water, there isn't much to prevent sunlight from flowing through them and turning them white. The water in the dark grey rain clouds absorbs or blocks the sunlight that falls on them. They also tend to obscure the sky, making it difficult for sunlight to be reflected off their sides.

Why do we believe that clouds, such as lenticular clouds that develop over hills, remain stationary despite severe winds?

Lenticular clouds resemble stationary clouds that originate mostly in the troposphere and are usually perpendicular to the wind direction. Because the cloud's droplets move quickly with the wind, yet fresh cloud drops constantly form in the same spot where the air is pushed up towards the hill, the cloud's front appears to be immobile. The droplets evaporate back into vapour towards the rear of the cloud, where the air comes down from the hill, thus the back of the cloud appears to remain motionless as well.

Massive Clouds Wildfires in Oregon have complicated firefighting efforts.

The Bootleg Fire is one of dozens of wildfires raging throughout the western United States, fuelled by dryness, heat, wind, and, in some cases, lightning. In all, the National Interagency Fire Center is monitoring 70 major fires that have burned over 1 million acres in 11 states, nearly all of which are located in the western part of the country. This does not include a slew of additional minor blazes. Thousands of people have been forced to flee their homes as a result of the fires, which have burned several properties along their path.

The fire was powerful enough to produce its own weather, releasing massive pyrocumulus clouds into the sky. According to fire authorities, one of those clouds fell on Thursday, causing embers to spread from the fire, triggering a new round of evacuation orders for towns on the fire's east flank.

Clouds' shape and structure

The height of the cloud's base above the Earth's surface divides most clouds into three groups (high, middle, and low). Other clouds are classified based on their distinct properties, such as whether they originate alongside mountains (lenticular clouds) or beneath existing clouds (Mammatus clouds).

Cloud height                                      Cloud type

5-13km (high clouds)                                            Cirrus, Cirrocumulus, Cirrostratus

2-7km (middle clouds)                                           altocumulus, altostratus

Surface-2km (low clouds)                                    stratus, stratocumulus, nimbostratus

Surface-13km (clouds with vertical growth)          Cumulus cumulonimbus

5-13km (contrails)                                                 contrails

The cloud heights in this table are for mid-latitudes only. The tropics and polar regions have varied cloud heights. A few more cloud forms can also be found in the upper layers of the atmosphere. Polar stratospheric clouds are found in the stratosphere, a layer of the atmosphere. Polar mesospheric clouds, also known as noctilucent clouds, are found in the mesosphere, a layer of the atmosphere.

The primary types of stratospheric and mesospheric clouds have common names. There might be stratiform veils or sheets, cirriform wisps, or stratocumuliform bands or ripples. They're only seen on rare occasions, mostly in the Earth's polar regions. Clouds have been discovered in the atmospheres of several planets and moons in the Solar System and beyond. They are typically composed of various chemicals, such as methane, ammonia, and sulfuric acid, as well as water, due to their different temperature properties.

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