NOAA’s Space Weather Prediction Center (SWPC) reported strong (G3) geomagnetic storming at 2359 UTC on March 6 in response to above-average coronal hole high-speed stream effects.
“The solar wind environment has tapered since the elevated activity, and as a result the G1 Watch for 07 March has been canceled,” the SWPC said. “Earth’s geomagnetic field is expected to be at quiet to unsettled levels with isolated periods of active conditions possible for the remainder of 07 March.”
According to the SWPC, during geomagnetic storms, “currents in the ionosphere, as well as the energetic particles that precipitate into the ionosphere add energy in the form of heat that can increase the density and distribution of density in the upper atmosphere, causing extra drag on satellites in low-Earth orbit. The local heating also creates strong horizontal variations in the in the ionospheric density that can modify the path of radio signals and create errors in the positioning information provided by GPS.” They also can induce harmful currents in the power grid and pipelines.
Spaceweather.com noted that the high-speed solar wind buffeting Earth’s magnetic field resulted in aurora borealis displays as far south as Massachusetts, Germany, and England. The sky in the north of England was “lit up,” according to one observer.
NOAA forecasters had been predicting a 50 percent chance of more geomagnetic storms on March 7, but that watch has been canceled. Spacewather.com said the negative magnetic polarity of the stream favors auroras.
As of 1400, the A index was 35, and the K index was 2. The A and K indices indicate fluctuations in Earth’s magnetic field, tied to specific geographic locations. The indices are directly related to the maximum amount of fluctuation — relative to a quiet day — in the geomagnetic field over a 3-hour interval. — Thanks to NOAA, Spaceweather.com