Solar Storm: The US National Oceanic and Atmospheric Administration (NOAA) has informed that a solar storm is likely to hit the Earth today, August 3, 2022.
- A 'hole' in the Sun's atmosphere is releasing gaseous materials which combined with a stream of strong solar winds, might result in a minor G1-class solar storm.
- The solar storm is likely to be weak but it is expected to impat satellite disruptions and cause power grid failures.
What are geomagnetic storms?
- A geomagnetic storm is a brief disturbance in the Earth's magnetosphere.
- The magnetosphere is a shield that protects our planet from dangerous solar and cosmic particle radiation, as well as solar wind erosion which is caused by the Sun's continuous outpouring of charged particles.
- When events such as solar flares send higher than normal levels of radiation towards Earth and this radiation interacts with the Earth’s magnetic field, a geomagnetic storm occurs.
- The frequency of occurrence of geomagnetic storms varies with the sunspot cycle which causes significant changes in the currents, plasmas, and fields in the Earth’s magnetosphere
- The US Space Weather Prediction Center (SWPC) defines a Geomagnetic Storm as ‘a major disturbance of 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 NASA, the solar magnetic field "interacts strongly" with the Earth's "oppositely oriented magnetic field".
- The Earth's magnetic field is then peeled open like an onion allowing energetic solar wind particles to stream down the field lines to hit the atmosphere over the poles.
- They are rated on a scale of 1 to 5, with 1 being the weakest and 5 being the strongest.
Solar storms are of the following types:
- Solar Flares: An instant outbreak of electromagnetic radiation in the sun’s atmosphere is known as solar flares. These solar flares are usually seen in active regions and often but not every time, occur with the coronal mass ejections (CME) and other solar phenomena.
- Coronal Mass Ejection: Coronal Mass Ejection (CME) refers to a notable release of plasma and a magnetic field through the solar corona. They frequently follow the solar flares and are generally present during a solar eruption.
- Geomagnetic Storm: Some disturbances in the earth’s magnetosphere occur because of the interaction of solar wind waves and clouds of magnetic fields with the earth’s magnetic field. This disturbance is known as a geomagnetic storm.
- Solar Particle Events: Solar particle events or solar proton event (SPE) or prompt proton event refer to the phenomenon that occurs when photons emitted by the sun become sped up either close to the sun or in interplanetary space by coronal mass ejection and shocks.
What are Sunspots?
- Sunspots dark regions of the Sun that are cooler than the surrounding photosphere which is the lowest layer of the solar atmosphere.
Effect of geo-magnetic storms on earth:
- When geo-magnetic storms occur, there is local heating in Earth's upper atmosphere which causes 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.
- The occurrence causes disruptions in navigation systems such as the Global Navigation Satellite System (GNSS) and create harmful geomagnetic induced currents (GICs) in the power grid and pipelines.
- It can also lead to voltage disruptions leading to power outages, changes in soil voltage that enhance corrosion in oil pipelines, disruption in cellular communications networks, exposure to elevated levels of radiation, and reductions in flights with polar routes.
- Astronauts on spacewalks face health risks from possible exposure to solar radiation outside the Earth’s protective atmosphere.
- Aurora is commonly visible at high latitudes during this time.
Geomagnetic Storm Occurrences:
- The geomagnetic storm of 1859, also called the Carrington storm, was the largest geomagnetic storm ever recorded.
- There were reports of intense brightening of auroras and reports of telegraph systems malfunctioning, electrocuting operators.
- In 1989, a geomagnetic storm generated ground produced currents resulting in power outages throughout most of Quebec and Auroras as far south as Texas.
What is Coronal Mass Ejection (CME)?
- Coronal Mass Ejection (CME) is among the biggest eruptions from the surface of the Sun.
- It contains a billion tons of matter accelerated to several million miles per hour into space.
- It runs through the interplanetary medium.
- It has the potential to impact anything that comes in its path, be it a planet or spacecraft.
How are geomagnetic storms predicted?
Solar Storms or geomagnetic storms are predicted by:
- Solar physicists and other scientists deploy computer models to forecast solar storms and other solar activity.
- Current models can forecast the arrival timing and pace of a storm.
- But the structure or orientation of the storm cannot be foreseen.
- Certain magnetic field orientations can cause the magnetosphere to respond more intensely, resulting in more violent magnetic storms.
- Thus, with the increasing worldwide reliance on satellites for nearly every activity, improved space weather forecasts and more efficient measures to safeguard satellites are required.