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Reduction in solar energy…

Reduction in solar energy… 7 February 2018

Reduced energy from the sun might occur by mid–century: Now scientists know by how much (via ScienceDaily)

The Sun might emit less radiation by mid–century, giving planet Earth a chance to warm a bit more slowly but not halt the trend of human–induced climate change.

The cooldown would be the result of what scientists call a grand minimum, a periodic event during which the Sun’s magnetism diminishes, sunspots form infrequently, and less ultraviolet radiation makes it to the surface of the planet. Scientists believe that the event is triggered at irregular intervals by random fluctuations related to the Sun’s magnetic field.

Scientists have used reconstructions based on geological and historical data to attribute a cold period in Europe in the mid–17th Century to such an event, named the “Maunder Minimum.” Temperatures were low enough to freeze the Thames River on a regular basis and freeze the Baltic Sea to such an extent that a Swedish army was able to invade Denmark in 1658 on foot by marching across the sea ice.

A team of scientists led by research physicist Dan Lubin at Scripps Institution of Oceanography at the University of California San Diego has created for the first time an estimate of how much dimmer the Sun should be when the next minimum takes place.

There is a well–known 11–year cycle in which the Sun’s ultraviolet radiation peaks and declines as a result of sunspot activity. During a grand minimum, Lubin estimates that ultraviolet radiation diminishes an additional seven percent beyond the lowest point of that cycle. His team’s study, “Ultraviolet Flux Decrease Under a Grand Minimum from IUE Short–wavelength Observation of Solar Analogs,” appears in the publication Astrophysical Journal Letters and was funded by the state of California.

Read more via ScienceDaily…