If we were to count all the clouds in the universe, we’d come up with more than 140 trillion – or trillions – if we had to do it ourselves. The 12-billion-year-old cloud contains more water than Earth’s oceans combined. And as water vapor condenses into bigger droplets, it forms precipitation. Heavy enough droplets fall to Earth and freeze into ice.

Cumulonimbus clouds

Most people have only vague memories of what cumulonimbus clouds are, but a recent event in California made them the biggest ever! These clouds are incredibly large and can be several kilometers high, with their bases close to the earth’s surface. Cumulonimbus clouds are often formed from lower-lying cumulus clouds. The clouds float in the air because their density is so low. The tallest cumulonimbus cloud ever observed reached a height of 75,000 feet.

Cumulonimbus clouds are the largest thunderstorms in U.S. history, but they are not the most common type of thunderstorm. They are often found in areas close to the equator, where the climate is warmer. These clouds form when air masses in an area reach a temperature that is warmer than the surrounding air. During a thunderstorm, these updrafts can carry up to six times more water than a typical cumulus cloud, so these storms can be particularly destructive.

Noctilucent clouds

In 1885, a volcanic eruption in Krakatoa, Indonesia, caused a phenomenon that made the skies glow like electric blue. It was then that watching sunsets became an international craze, and people began to notice the mysterious glowing blue clouds. They remained in the sky after the Krakatoa eruption, and the phenomenon has spread southward since then. Originally seen only in the northern sky, noctilucent clouds can now be seen in night skies of Virginia and Colorado.

Observations of noctilucent clouds from satellites have revealed a surprising trend. Despite their name, they are mostly visible at night and occur in areas of the Earth’s upper atmosphere above 70 to 75 degrees latitude. Scientists have since identified a bright scattering layer as the poleward extension of noctilucent clouds. The first satellite to observe them was the Solar Mesospheric Explorer, which had an ultraviolet spectrometer and mapped cloud distributions for the 1980s.

Giant raindrops

Scientists have discovered the giant raindrops in the sky. The scientists were tasked with culling the data collected from several missions that they conducted in 2002. The missions covered the United States, Africa, Brazil, and the South Pacific. Their findings are published in the peer-reviewed journal American Geophysical Union. They are still processing data from all of these missions. They are looking for more evidence of the giant raindrops in the sky.

The researchers of the UW Cloud and Aerosol Research Group observed the giant raindrops during two separate events in 1995. One occurred over the Marshall Islands when a cloud spawned from a burning forest in Brazil. The other occurred when clean marine air over the Marshall Islands rained down from the sky. The researchers are co-authors of a paper on their findings. Interestingly, no one is able to explain why the giant raindrops were formed. The researchers speculate that they were produced by a collision-coalescence process and produced super-large raindrops.

Highest cloud top

A cluster of towering thunderheads spotted over the Pacific Ocean on Dec. 29, 2018 has now been confirmed to have the coldest cloud top ever recorded. The cloud measured minus-168 degrees Fahrenheit – 40 degrees colder than the lowest temperature ever recorded on Earth’s surface in Antarctica in 1983. North America’s previous lowest cloud top temperature was minus-81 degrees in 1947. If this is the coldest cloud top ever recorded, then it might just be the coldest.

Historically, cloud top height was measured using the method of triangulation, where two images acquired from different observation angles were combined to obtain an estimate of cloud top height. This method can only be used for isolated clouds, but it does provide an estimate of cloud top height that is approximately 0.7 kilometers (2.6 miles) higher than the surface of the Earth. A better method of estimating cloud top height using temperature is described in this paper.

Rarest cloud formation

The nacreous clouds are some of the rarest cloud formations. They can be mistaken for cirrus clouds, but they change dramatically before and after sunrise or sunset. They appear as kaleidoscope-like iridescent streaks and are similar in appearance to aurora borealis. They form at high altitudes and are created by two different areas of air moving at very different speeds. This makes them the most interesting and beautiful clouds to observe.

Asperitas is the world’s most rare cloud formation, which first appeared in the International Cloud Atlas in 1951. This cloud is so rare that the International Cloud Atlas has named it a separate entity. In addition, this formation is only visible at certain times of the day, making it one of the most fascinating forms of cloud in the sky. You can catch a glimpse of it from the air in the pictures below. Once you’ve seen it, you’ll wonder how you ever survived without it.