Science for Everyone

On Cloud Nine

Post by Bailey Moritz, Scallop Research Intern

Wherever you are right now, stop, go outside, and look up at the sky. Are there clouds up there? Do they appear fluffy, wispy, or flat? Maybe its sunset and they are streaked with colors. What shapes come to mind? In The Cloudspotter’s Guide,  Gavin Pretor-Pinney describes clouds as the most egalitarian of natures displays, because anyone can view them, at absolutely any time they want. And when you start to pay more attention to them, you begin to notice the variety of clouds that appear are as vast as the sky itself. Summer is the time to have your head in the clouds, and here are a few of the types we have seen flying high above Hurricane Island recently;

On a sunny day, the cumulus clouds are piling up, with a cirrus cloud known as a horsetail in the background.

Cumulus- When we think of clouds, this puffy, friendly type is probably the first image that comes to mind. As water evaporates from the earths surface, it creates a thermal column of air that begins to form water droplets once it reaches a layer of cooler air. These water droplets build and “accumulate” to form a cumulus cloud. As more and more water evaporates, the cloud grows bigger, and eventually becomes the giant storm cloud, cumulonimbus, capable of showering us with lightning, rain, and hail. The water in a typical cumulus cloud weights about as much as 80 elephants!

Cirrus- These clouds are the highest forming variety. Deriving from the latin word for “lock of hair”, the cirrus’ wispy appearance is actually due to the fact that they are made of ice crystals expanding across the upper reaches of the atmosphere. Even on the hottest of days, there may be snow overhead!

A family of virga fall from above.

Virga- When higher clouds like cirrus actually start to precipitate, or rain down their water, charismatic formations known as virga may appear. As the precipitation falls, it hits a warmer, dryer layer of air and the water evaporates before reaching the earth.

Fog- Fog is something we are very familiar with on the coast of Maine. A type of stratus cloud, coastal fog forms when air passes over a stretch of warm ocean water, and then encounters a colder current. This sudden drop in temperature right at the waters surface basically causes a water droplet cloud to form low to the ground, enveloping us all.

Contrails- We leave our mark on the sky as much as we do on the earth. Contrails form when the hot exhaust from airplanes cools rapidly into ice crystals in its wake. The tiny particles in the exhaust give the ice something to cling to and they can grow rapidly. If contrails don’t appear behind a plane or they disappear really quickly, it’s a sign that the air is dry and clear skies will likely continue.

Fog rolls in over the quarry

Who knows what worldy destinations these contrails lead to.

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