Meet clouds by name

Monday, August 3, 2009
by Conrad Storad

Clouds can make us happy. Clouds can make us sad. Big puffy white clouds floating through a bright blue summer sky make us smile. But boiling black storm clouds slashed with jagged lightening and crashing thunder make us run for shelter.

To be precise, a cloud is nothing more than a collection of water particles or ice crystals floating in the atmosphere. There are 10 different types of clouds. In 1803, English pharmacist Luke Howard identified these distinct cloud types. He then devised a system of cloud classification.

Howard’s cloud classification system uses Latin words that describe the placement (high) and appearance (spread out) of clouds. For example, using Howard’s system, a high (alto), spread out (stratus) cloud is called an altostratus cloud.

Images of different cloud typesHIGH

Clouds forming in high altitudes are called cirrus, cirrostratus, and cirrocumulus. It is so cold in the upper atmosphere that high altitude clouds contain ice crystals instead of water particles.

CIRRUS clouds form when the wind blows these ice crystals into wispy streaks that look like thin horse tails.

CIRROCUMULOUS clouds look like upside down waves rolling across the sky.

High, thin CIRROSTRATUS clouds look much like stratus clouds, but cirrostratus clouds contain ice crystals and are much higher.

MIDDLE

Altocumulus and altostratus are middle-altitude clouds. Even though the word alto means “height” in Latin, these are not the highest clouds.

ALTOCUMULUS clouds look fleecy and have dark, shadowed sides.

ALTOSTRATUS clouds are flat and make the sun look as if it is being seen through a misty glass.

LOW

Five of the 10 types of clouds can be found at low altitudes. The low-altitude clouds are called cumulonimbus, cumulus, stratus, stratocumulus, and nimbostratus.

CUMULONIMBUS clouds are piled up high like scoops of dark ice cream. These clouds usually bring rain showers.

STRATOCUMULUS clouds are spread out heaps of dense cover that rise higher in the atmosphere.

Dark, flat NIMBOSTRATUS clouds often produce rain or snow.

CUMULUS clouds look like giant heads of cauliflower because they are white and fluffy.

STRATUS clouds are spread out, dull clouds usually found at ground level. Stratus clouds may so close to the ground they are identified as fog.