Solar Winds Rock Earth, Trigger Geomagnetic Storms

A high-speed solar wind stream is buffeting Earth's magnetic field and causing geomagnetic storms around the Arctic Circle, according to the National Oceanic and Atmospheric Administration (NOAA).

Geomagnetic storms occur when a strong gust of solar wind hits the Earth's magnetosphere and can cause Aurora in high-latitude parts of the Earth (mostly northern Michigan and Maine).

The solar wind speeds have exceeded 700 kilometer per second (or 1.5 million miles/hour), which are coming from a large coronal hole in the northern hemisphere of the Sun.

The high speed solar wind could possibly interfere with satellites and power grid fluctuations can occur. Migratory animals are affected due to the geomagnetic storms at the G1 Minor level and higher levels.

“Last night saw the expected arrival of a co-rotating interaction region (CIR) and the subsequent high speed solar wind. These high speed winds should continue for at least 2 more days, buffeting the Earth and giving us some chances of minor geomagnetic storming,” NOAA said in a statement.

Co-rotating interaction region are long lasting large-scale plasma structures generated in low and middle latitude regions of the heliosphere by the interaction of a stable fast solar wind stream with the surrounding slow solar wind.

Co-rotating interaction regions possibly play a role in determining solar modulation of galactic and anomalous cosmic rays during periods of low to moderate solar activity.

Earth itself is largely protected from the solar wind by its magnetic field, which deflects most of the charged particles. However some of the charged particles are trapped in the Van Allen radiation belt.

A smaller number of particles from the solar wind manage to travel, as though on an electromagnetic energy transmission line, to the Earth's upper atmosphere and ionosphere in the auroral zones. The only time the solar wind is observable on the Earth is when it is strong enough to produce phenomena such as the aurora and geomagnetic storms.

The solar wind creates the heliosphere, a vast bubble in the interstellar medium that surrounds the solar system. Other phenomena include geomagnetic storms that can knock out power grids on Earth, the aurorae (northern and southern lights), and the plasma tails of comets that always point away from the Sun.

NOAA space weather prediction center issued a 3-day solar-geophysical forecast on August 24 at 10:00 pm UTC, when solar activity is expected to be very low for the next three days.

Geomagnetic field activity is expected to be at unsettled-to-active levels on August 25, and at mostly-unsettled levels on August 26 due to a recurrent coronal hole high speed stream, the space weather prediction center said.

The center said activity on August 27 will at quiet- to-unsettled levels as the effects of the coronal hole high speed stream subside.

The greater than 2 megaelectron volt (MeV) electron-flux at geosynchronous orbit is expected to be at high levels from August 25 to September 12, the center said in the solar and geomagnetic activity forecast.