Wednesday, January 23, 2019

Minor Geomagnetic Storm May Hit Earth on Thursday


A G1-class (minor) geomagnetic storm may hit the Earth on Thursday, January 24, according to latest predictions made by National Oceanic and Atmospheric Administration (NOAA).

The storm is expected to begin when a stream of solar wind reaches our planet’s magnetic field. The gaseous material is flowing a hole in the sun's atmosphere, with a velocity of about 600 km/s (or 1.34 million mph).

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.

A minor geomagnetic storm can trigger auroras visible around Earth's poles and weak power grid fluctuations. Such storm could also have minor impact on satellite operations.

NOAA informs that solar activity is expected to be generally at very low levels until February 16. However, unsettled to active levels of geomagnetic field activity are possible between January 31 and February 3 due to influence from 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 (moderate) 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.

No comments:

Post a Comment