A long-lived cluster of sunspots, AR 3697 erupted in a number of M-class flares on 8 June, resulting in a solar radiation storm that caused a blackout of high-frequency radio communications on the sunlit side of the Earth. Instruments have now indicated that this was the most intense solar radiation storm in seven years.
The Sun on 8 June. (Image Credit: NASA/SDO).
New Delhi: M-class flares from a fierce and long-lived cluster of sunspots designated as Active Region 3697 caused the most intense solar radiation storm in seven years, on 8 June. The Space Weather Prediction Centre (SWPC) of the US National Oceanic and Atmospheric Administration (NOAA) had initially forecasted a moderate solar radiation storm, but the instruments have now revealed that the event was a strong solar radiation storm, the strongest recorded since 2017. This is a different type of event than the historic May geomagnetic storm.
The alert issued by the SWPC. (Image Credit: NOAA).
The different types of Sun storms
A solar radiation storm consists of a soup of high energy particles travelling outwards from the Sun at tremendous speeds. These particles are primarily protons, that travel at nearly the speed of light, arriving at the Earth within minutes of an eruption. Plasma or hot gas from the outer atmosphere of the Sun is violently shed during coronal mass ejections (CMEs), that move slowly, travel at different speeds, and arrive at the Earth a few days later, disrupting power grids, interfering with satellite communications and increasing the volume of the atmosphere.
How are Sun storms measured?
Solar Radiation Storms are measured on a scale that goes through S1 to S5, while Geomagnetic Storms are measured on a scale that goes from G1 to G5. Radio blackouts are measured on a scale that goes from R1 to R5. The numbers on each of these scales are associated with minor, moderate, strong, severe and extreme events. In May, a G5 geomagnetic storm was observed, while the 8 June event was a R3 solar radiation storm.
The effects of solar radiation storms
Minor solar radiation storms just cause temporary blackouts of high-frequency radio comms on the sunlit side of the Earth. In more intense events, passengers and crew of high altitude aircraft as well as astronauts on board space stations are exposed to elevated levels of radiation. Extreme solar radiation storms can knock out satellites, permanently destroy solar panels, and cause serious noise in imaging data gathered by satellites.
Shambhu Kumar is a science communicator, making complex scientific topics accessible to all. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
