Clouds form when water vapor condenses as liquid water onto particles in the Earth's atmosphere and are composed of billions of tiny water droplets or ice crystals, depending on how high they are in the atmosphere. The three basic patterns of clouds are cirrus (wispy), stratus (sheets, or layers) and cumulus (the fluffy, cotton ball-like ones). Clouds can form low to the ground (like stratus clouds), in the middle of the atmosphere (like altocumulus clouds) or high up (like cirrus clouds). Clouds can affect Earth's climate by either reflecting incoming solar rays back out to space or by absorbing and re-emitting infrared radiation coming from Earth's surface. Read the latest research on the various types of clouds and how clouds form below.
In July there was a large "A" written in the sky over the ocean near the Kamchatka Peninsula, in eastern Russia. In an image of this "A" snapped from space, the letter looks like it could have been made by an airplane that was using standard skywriting.
Green globs of little critters in the ocean are responsible for half of the cloud droplets that cover the Southern Ocean during the summer – the link between the critters and clouds provides needed insight for predicting the effects of climate change.