Geomagnetic Storm Likely To Hit Earth Today, Could Impact Power Systems, Satellite Operations

A geomagnetic storm is a major disturbance in the Earth's magnetosphere that occurs when there is a very efficient exchange of energy from the solar wind into the space environment surrounding Earth.

New Delhi: A minor geomagnetic storm is likely to hit Earth on April 7, Thursday, according to the Space Weather Prediction Center (SWPC) of the National Oceanic and Atmospheric Administration (NOAA). 

"A G1 (Minor) geomagnetic storm watch is in effect for 6-7 Apr in response to the anticipated arrival of the 3 April CME, which originated from a filament eruption that was centered near S22W30," the SWPC said on its website.

A storm watch means that severe weather has not occurred yet, but upcoming weather conditions are expected to result in potentially dangerous weather. 

What Is A Geomagnetic Storm?

A geomagnetic storm is a major disturbance in the Earth's magnetosphere that occurs when there is a very efficient exchange of energy from the solar wind into the space environment surrounding Earth, according to the NOAA. Geomagnetic storms result from variations in the solar wind that produce major changes in the currents, plasmas, and fields in Earth's magnetosphere. The solar wind conditions that are effective for creating geomagnetic storms are sustained for several hours of high-speed solar wind. Most importantly, a southward directed solar wind magnetic field is sustained at the dayside of the magnetosphere. 

Geomagnetic storms are measured by ground-based instruments that observe how much the horizontal component of Earth's magnetic field varies. Based on this measurement, the geomagnetic storms are categorised from G1 (minor) to G5 (extreme). 

Transformers in power grids are damaged in the most extreme cases. Spacecraft operation and satellite tracking can also be hindered, high frequency radio propagation and satellite navigation systems can be blocked.

What Is A Coronal Mass Ejection?

Coronal Mass Ejections (CMEs) are large expulsions of plasma and magnetic field from the Sun's corona, or the outer solar atmosphere, and can eject billions of tons of coronal material. 

The corona is structured by strong magnetic fields. When these fields are closed, often above sunspot groups, the confined solar atmosphere can suddenly and violently release bubbles of gas and magnetic fields called coronal mass ejections. 

Billions of tons of coronal material can be accelerated to several million miles per hour in a spectacular explosion. Solar material streams out through the interplanetary medium, and impacts any planet or spacecraft in its path. 

Predictions Of A CME Strike And Geomagnetic Storm

According to spaceweather.com, April 6 passed "quietly", contrary to the predictions of a CME strike and geomagnetic storm. However, it is likely that the Earth will be hit by a CME on April 7. 

"NOAA forecasters expect a glancing blow on April 7, possibly sparking minor G 1-class geomagnetic storms," SpaceWeather said on its website. 

How Could The G 1-Class Geomagnetic Storm Impact Earth?

A minor geomagnetic storm could impact power systems and spacecraft operations. For instance, weak power grid fluctuations can occur. Satellite operations could be impacted, and migratory animals may be affected. 

People living in northern Michigan and Maine can witness a spectacular view in the night sky because aurora is commonly visible at high latitudes.