Researchers have found that the last time the thermosphere was rated ‘hot’ was around 2003 (see chart below). Now with a deep solar minimum upon us, the obvious question is: what effect might this have on our planet as a whole?
Sept. 27, 2018: The sun is entering one of the deepest Solar Minima of the Space Age, says Dr. Tony Phillips at Space Weather.
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, it 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 solar cycle affects our planet,” explains Mlynczak, who is the associate principal investigator for SABER.
When the thermosphere cools, it shrinks, literally decreasing the radius of Earth’s atmosphere.
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Above: An historical record of the Thermosphere Climate Index. Mlynczak and colleagues recently published a paper on the TCI showing that the state of the thermosphere can be discussed using a set of five plain language terms: Cold, Cool, Neutral, Warm, and Hot.
via Tallbloke’s Talkshop
September 28, 2018 at 04:28AM