Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

February 15, 1999
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La Niña Earth
Credit: TOPEX/Poseidon Team, CNES, JPL, NASA

Explanation: La Niña is a temporary climate change caused by unusually cold water in the central Pacific Ocean. Cold water topping an unusually low sea level is shown as purple in the above false-colour picture taken by the orbiting TOPEX/Poseidon satellite in mid-January. Such cold water tends to deflect winds around it, changing the course of weather systems locally and the nature of weather patterns globally. This year's La Niña appears to have weakened over the past few months, indicating a slow return to more normal seasonal weather. The full effects of the preceding El Niño and the present La Niña are still under study.

Tomorrow's picture: Bubbles from M87


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
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