Solar maximum is a peak in the sun’s activity that occurs around the middle of each solar cycle.
The incoming maximum could have a greater impact on space weather and the power grid than the previous one.
People on Earth obviously won’t notice most of these effects, but you may see brighter auroras.
This recounted essay is based on a conversation with Matthew Owensprofessor of space physics at the University of Reading which researches space science and weather in relation to solar activity and solar maximum. It has been edited for length and clarity.
We are close to the next solar maximum, expected for 2025.
Solar maximum represents a peak in solar activity when the sun’s magnetic field reaches its strongest, messiest, and most dynamic point.
This increased solar activity can cause extreme space weather events, including solar flares and eruptions. It can also disrupt radio communications and the electrical grid and have serious consequences for the health of astronauts.
The dangers mainly concern large-scale infrastructure. On an individual level, people on Earth are unlikely to see the effects of solar maximum directly.
This solar maximum will likely be stronger than the last one
Solar cycles typically last 11 years, and solar maximum occurs roughly in the middle of each cycle.
The last solar maximum occurred between 2012 and 2014 and was particularly weak, one of the smallest in about 100 years. As a result, space weather was generally weaker than normal.
This next solar maximum, however, looks like it could return to mean values. This means that we could see a greater impact on space weather and its potential consequences.
What does solar maximum mean for the Earth
Solar activity occurs primarily due to the agitated motions of plasma within the sun, which creates and changes the sun’s magnetic field.
The sun’s magnetic field reaches its strongest during solar maximum, leading to an increase in events such as solar flares and coronal mass ejections.
Solar flares consist of high-energy photons, such as X-rays, which can increase ionization in Earth’s upper atmosphere and disrupt radio communications.
CMEs, on the other hand, are eruptions of the sun’s magnetic field and material that fuel geomagnetic storms. These disturbances to the earth’s magnetic field can damage the energy distribution network.
During solar maximum, we will also see more explosions of very high-energy particles traveling towards Earth. These outbursts are about four times more likely to occur during a solar maximum than a solar minimum.
And because the particles in these explosions are radiation, they pose a serious health risk to astronauts, passengers and crew on high-latitude, high-altitude aircraft. They can also damage space hardware and lead to the loss of the satellite.
You probably won’t notice most of these effects
Many effects of solar maximum are ephemeral, which remains a major challenge in studying space weather.
For example, it’s often difficult to definitively link a problem in the power grid to space weather, even if solar activity caused that problem.
The only concrete effect that we can predict with certainty is that you will probably see auroras, i.e. the northern and southern lights, more frequently at different latitudes.
During solar maximum, more solar particles interacting with molecules in Earth’s atmosphere result in brighter displays of auroras that may extend further north or south than usual.
Scientists have also found signs of the solar cycle, such as changes in temperature and ozone levels, in the Earth’s stratosphere.
While scientists include these changes from the sun when considering long-term climate variations, these effects on climate aren’t as significant or severe as factors like volcanoes, carbon dioxide emissions and other human activities.
Our addiction to technology ups the ante
Our collective dependence on technology and space increases every year, which makes space weather an ever greater risk.
The threat it poses to the electricity grid is of greater concern, not least because of the cascading risks presented by power failure for an extended period.
It all boils down to probability, though. A stronger solar cycle just means a higher probability of extreme space weather events. It does not guarantee extreme space weather conditions.
In fact, extreme space weather can occur even in small solar cycles. During Cycle 24’s Small Solar Maximum, a spacecraft far from Earth encountered one of the most energetic CMEs ever seen.
A CME of this magnitude aimed at Earth could have caused serious interruptions to the energy distribution network or serious damage to the satellite hardware.
Read the original article on Business Insider