Over the weekend, a middle latitude coronal hole (88) started to face earth. This is the same coronal hole that was responsible for a moderate (G2) geomagnetic storm last month. Now it seems like the same coronal hole is at it again, spewing high-speed solar wind – headed towards Earth this week.
According to Space Weather Prediction Center (SWPC), a minor (G1) geomagnetic storm watch is now in effect for Tuesday and Wednesday. The storm watch was issued “due to the arrival of a negative polarity coronal hole high-speed stream,” SWPC detailed on its website.
C. Alex Young, associate director for science in the heliophysics science division at NASA’s Goddard Space Flight Center, published in a report Monday that “three substantial coronal holes” arrived on his radar last week. Young describes coronal holes as an “open magnetic field from which high-speed solar wind rushes out into space.” If the high-speed solar wind is earth facing, then “it interacts with Earth’s magnetosphere” and lead to all sorts of problems.
“For much of this week the sun featured three substantial coronal holes (Apr. 3-6, 2018). Coronal holes appear as large dark areas which are identified with arrows in the still image. These are areas of open magnetic field from which high speed solar wind rushes out into space. This wind, if it interacts with Earth’s magnetosphere, can cause aurora to appear near the poles. They are not at all uncommon. Credit: Solar Dynamics Observatory, NASA.”
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