Sunday, November 5, 2017

Minor Geomagnetic Storm Expected to Hit Earth November 7-8

Credit: NOAA

National Oceanic and Atmospheric Administration (NOAA) reports that a G1-class (minor) geomagnetic storm is expected to hit Earth when a new solar wind stream wind will arrive at our planet on November 7-8. The source of this stream is a large northern hole in the sun's atmosphere.

As a result of the upcoming minor geomagnetic storm, auroras could be visible around Earth's poles and weak power grid fluctuations could occur. Such storm could also have minor impact on satellite operations.

In general, geomagnetic storms 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. While the storms create beautiful aurora, they also can disrupt navigation systems such as the Global Navigation Satellite System (GNSS) and create harmful geomagnetic induced currents in the power grid and pipelines.

NOAA also informed that solar activity is expected to be generally at very low levels in November with a slight chance for C-class solar flares between November 15 and 25 due to
flare potential from Active Regions (AR) on the sun, designated AR 2685 and 2686. Moreover, NOAA forecasts that there is also a chance of a G2-class geomagnetic storm on November 9 due to recurrent coronal hole high speed streams (CH HSSs) effects.

Fast CH HSSs can impact Earth’s magnetosphere enough to cause periods of geomagnetic storming to the G1-G2 levels; although rarer cases of stronger storming may also occur. The larger and more expansive coronal holes can often be a source for high solar wind speeds that buffet Earth for many days.

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