Tuesday, May 22, 2018

Minor Geomagnetic Storm Possible on Wednesday


A G1-class (minor) geomagnetic storm may hit Earth on Wednesday, May 23, when a stream of solar wind is expected to arrive at our planet. The gaseous stream originates from a northern hole in the Sun's atmosphere.

In result of the possible Wednesday’s storm, visible auroras could be concentrated around Earth's poles and weak power grid fluctuations could occur. The 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.

National Oceanic and Atmospheric Administration (NOAA) informs that solar activity is expected to be generally very low in the coming weeks. A moderate (G2-class) geomagnetic storm is predicted for June 2 due to the influence of a recurrent, negative polarity coronal hole high-speed stream (CH HSS).

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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