A geomagnetic storm occurred. FILE IMAGE
A geomagnetic storm occurred. FILE IMAGE

Geomagnetic storm could affect radio communication in space

By Genevieve Serra Time of article published Oct 13, 2021

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CAPE TOWN – The South African National Space Agency (Sansa) has confirmed a global geomagnetic storm which could disrupt communications with spacecraft and satellite positions and calculations.

But due to South Africa being at 35 degrees latitude to the sun, it’s predicted local radio disruption and power systems impact is minimal.

On Sunday, an eruption of the sun produced an ejection showing effects to the Earth’s magnetic field.

According to space researchers, eruptions on the sun send a blob of plasma into space and this plasma travels along the Sun’s magnetic field. If this geometry is correct, it can hit Earth and “deform” the Earth’s magnetic field.

Sansa said their Weather Centre is constantly monitoring the disturbances and how it would impact and affect the nation’s technology and operations.

Experts say this is a normal occurrence which happens a few times a year when the sun is active.

A Sansa statement said: “An eruption on the sun a few days ago (9 October 2021) produced a Coronal Mass Ejection (CME) that is now showing its effects on the Earth’s magnetic field. Magnetometer readings around the world are showing moderate disruptions. A disturbance of this size is a G2 storm on the NOAA scale. NOAA is the National Oceanic and Atmospheric Administration and their headquarters are located in Boulder, Colorado, USA.

“The NOAA scale goes from 1 (minor) to 5 (extreme). A G2 storm can disrupt communication with spacecraft and require updates to satellite position calculations from increased drag.

“At high latitudes (above 55 degrees), high frequency radio communication with aircraft can be impacted. South Africa is at 35 degrees latitude, so the forecast for local radio disruption and power systems impact is minimal. The Sansa Space Weather Centre is continuously monitoring solar activity and providing alerts on impacts that affect our nation’s technology and operations.”

They added that the magnitude of the magnetic field’s power was rather low: “The K-index is a measurement of the disturbance of the magnetic field relative to a quiet day.

Sansa’s description. SUPPLIED

They detailed this via graphs sent to the media.

“An undisturbed day will have a K of zero, while the largest known disturbance for a given location will have a K of 9. Values of K less than four are ordinary wiggles in the Earth’s magnetic field.

“Values higher than 4 indicate storms of increasing strength.

“At the storm’s peak Earth experienced a planetary K-index of six, while Sansa in Hermanus observed a slightly lesser K-index disturbance of five. The local geomagnetic disturbance was at G1 storm level based on Hermanus data, but globally a G2 storm was observed.

Sansa’s description. SUPPLIED

“The red line on the planetary K-Index indicating K6 is the value of the magnetic disturbance as observed by earth. It lessens as the latitude decreases.”

Dr Martin Snow, Sansa SARChi research chair in Space Weather, said the disturbance would be minimal and that spacecraft could expect loss of communication at certain frequencies.

“This geomagnetic storm is relatively minor and will primarily impact high latitudes. At the latitude of South Africa, there will be very minor effects.

“Satellite operators, such as Sansa’s team in Hartebeesthoek, will need to compensate for increased atmospheric drag.

“Aircraft at high latitudes will need to be prepared for loss of radio communication at some frequencies.”

Snow told Weekend Argus that this was something that was a common occurrence.

“A geomagnetic storm of this size happens a few times per year when the sun is active,” he said.

He explained the reasons why it happened was due to an exchange of a plasma blob into space which travelled along the sun’s magnetic field then to the Earth’s atmosphere and its occurrence could increase.

“Not every eruption produces an event that hits the Earth, so the space weather forecasters at SANSA are always on the lookout to see where the eruption will go. As the sun becomes more active over the next several years, the strength and number of such storms is likely to increase.”

He added that there was no need to panic as a stronger storm could potentially affect power systems and our GP’s location calculation. “A storm of this size is mostly an alert to spacecraft operators and the aviation sector.

“A stronger storm could impact power systems and introduce errors in GPS location calculations.”

Good news they added, was that a new weather centre was under construction which could be operational next year: “The South African National Space Agency is currently constructing a new state of the art Space Weather Centre.

“This facility will monitor space weather on a 24/7 basis and is on track to be operational in 2022.”

Weekend Argus

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