Source: http://spaceweather.com/ Saturday, Sep. 29, 2018
THE CHILL OF SOLAR MINIMUM: The sun is entering one of the deepest Solar Minima of the Space Age. Sunspots have been absent for most of 2018, and the sun’s ultraviolet output has sharply dropped. New research shows that Earth’s upper atmosphere is responding.
“We see a cooling trend,” says Martin Mlynczak of NASA’s Langley Research Center. “High above Earth’s surface near the edge of space, our atmosphere is losing heat energy. If current trends continue, the upper atmosphere could soon set a Space Age record for cold.”
These results come from the SABER instrument onboard NASA’s TIMED satellite. SABER monitors infrared emissions from carbon dioxide (CO2) and nitric oxide (NO), two substances that play a key role in the energy balance of air 100 to 300 kilometers above our planet’s surface. By measuring the infrared glow of these molecules, SABER can assess the thermal state of gas at the very top of the atmosphere–a layer researchers call “the thermosphere.”
“The thermosphere always cools off during Solar Minimum. It’s one of the most important ways the 11-year solar cycle affects our planet,” explains Mlynczak, the associate principal investigator for SABER.
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