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World Meteorological Day celebrates importance of clouds for weather, climate and water

A formation of Altocumulus clouds. Source: WMO
A formation of Altocumulus clouds. Source: WMO

World Meteorological Day celebrates importance of clouds for weather, climate and water

Clouds inspire art and thought, but few natural phenomena are as important to weather, climate or water, the United Nations meteorological agency today said, launching a digital cloud atlas to celebrate World Meteorological Day.

“If we want to forecast weather we have to understand clouds. If we want to model the climate system we have to understand clouds. And if we want to predict the availability of water resources, we have to understand clouds,” said said World Meteorological Organization (WMO) Secretary-General Petteri Taalas.

World Meteorological Day commemorates the coming into force on 23 March 1950 of the convention establishing the WMO. This year's theme is “Understanding Clouds.”

In conjunction with the Day, WMO today launched for the first time a primarily on-line digital edition of the International Cloud Atlas, which features hundreds of images and information about clouds, as well as meteorological marvels, such as rainbows and halos.

The new Atlas “combines 19th century traditions with 21st century technology,” the UN agency said, noting that the International Cloud Atlas was first published some 200 years ago.

VIDEO: International Clouds Atlas Web. Credit: WMO

It contains pictures, definitions, and explanations that are accepted and used by all of WMO's 191 members, as well as all types of measurements from space and through remote sensing.

For example, the Atlas includes “volutus, a roll cloud; clouds from human activities such as the contrail, a vapour trail sometimes produced by airplanes; and asperitas, a dramatic undulated cloud which captured the public imagination,” according to WMO.

In his message for the Day, Mr. Taalas noted the importance of understanding weather and climate changes in protecting people and property, and assisting communities to become more resilient.

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