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Volcanoes. You might think of big, loud eruptions.

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Glowing lava and dark volcanic ash entering the sky.

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But when volcanoes aren’t erupting

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they can leak reactive gases into the atmosphere

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that form tiny particles known as aerosols.

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Aerosols are these tiny particles which are suspended in the atmosphere

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and they’re many times smaller than the human hair.

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They can scatter and absorb light and can affect clouds.

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Studies have shown that volcanic aerosols can change

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the properties of water droplets that make up clouds.

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To learn more about these changes

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scientists analyzed several years of observations

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from NASA and European Space Agency satellites.

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They specifically looked at how the properties of water droplets

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changed around active volcanoes

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To avoid interference from other aerosol sources, such as city pollution

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researchers compared three isolated islands with volcanic activity to three islands without.

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Around the islands with no volcanic activity,

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water droplets were mostly unaffected

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but around the islands with volcanic activity

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water droplets were smaller and the clouds appeared brighter.

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Clouds with smaller droplets tend to be brighter 

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and reflect more heat energy back to space.

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If the amount of heat reflected into space changes

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this can affect things like rainfall and winds.

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Learning more about aerosols and how they interact with clouds 

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will help scientists like me to better understand and predict future weather and climate.

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