Scientists have discovered that sunspots are not the only thing from the Sun that have a significant and varied impact on the Earth.
There is a “solar cycle” of approximately 11 years. Variation of the Sun’s impact on the Earth during those 11 years is generally thought to be due to sunspots. The Sun also shoots high-speed winds at the Earth, however, and scientists have just discovered that these super winds significantly affect the Earth in several ways.
Earth Blasted with High-Speed Solar Winds
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The lead author of the new study, Sarah Gibson, states: “The Sun continues to surprise us…. The solar wind can hit Earth like a fire hose even when there are virtually no sunspots.”
Researchers from the High Altitude Observatory of the National Center for Atmospheric Research (NCAR) and the University of Michigan conducted this new study. They reported this week that the Earth was significantly affected last year by these super winds, despite there being low solar energy and nearly no sunspots. “Earth was bombarded last year with high levels of solar energy at a time when the Sun was in an unusually quiet phase and sunspots had virtually disappeared.”
Sunspots
Sunspots are concentrated magnetic fields that look like dark spots on the sun’s surface. At solar maximum (during the 11-year solar cycle) the sunspots are most abundant. At this time, “intense solar flares occur daily and geomagnetic storms frequently buffet Earth.” This knocks out satellites and causes troubles with our communications networks. Scientists have known about these sunspots for centuries.
Solar High-Speed Winds
The researchers of this new study decided to examine something scientists don’t know so much about — streams of high-speed winds from the Sun. In addition to sunspots, these streams of wind also send “turbulent magnetic fields” outwards into the solar system and to Earth.
The result of these high-speed solar winds on Earth is that they “intensify the energy of the planet’s outer radiation belt” and result in serious weather hazards, navigation problems, and hazards for communications satellites. They also threaten astronauts in the International Space Station.
These high-speed winds can effect Earth for as long as 7-10 days. They come periodically because of the Sun’s rotation. “The streams strike Earth periodically, spraying out in full force like water from a fire hose as the Sun revolves.”
Previously, scientists thought that these wind streams decreased (or mostly disappeared even) when the solar cycle was at its lowest extent. However, the researchers identified that these solar streams remained strong during the solar minimum this decade. And the Sun’s effect on Earth’s outer radiation belt “was more than three times greater last year than in 1996.” During this time, “strong, long, and recurring high-speed streams of charged particles buffeted Earth.”
Results for Humans
All of the effects on Earth and humans are unknown. We know that these magnetic streams cause problems for satellites and technology, but the full extent is unclear.
Janet Kozyra, co-author of the study from the University of Michigan, states: “The Sun-Earth interaction is complex, and we haven’t yet discovered all the consequences for the Earth’s environment of the unusual solar winds this cycle.”
Co-authored by scientists from the National Oceanic and Atmospheric Administration (NOAA) and NASA, the study was published in the journal Geophysical Research – Space Physics on Friday.
Image Credit 1: Ethan Hein via flickr under a Creative Commons license
Image Credit 2: Ethan Hein via flicker under a Creative Commons license
Image Credit 3: Ethan Hein via flickr under a Creative Commons license
Image Credit 4: Ethan Hein via flickr under a Creative Commons license