The Sun is experiencing long-term changes, as revealed by an international team of researchers led by the University of Birmingham, who have identified a major squeeze in the four most recent solar activity cycles.

A recent paper in the Monthly Notices of the Royal Astronomical Society by the University of Birmingham-led team reveals that Solar magnetic activity is now being forced into a shallow layer of the Sun, just beneath the solar surface, marking a major change to our host star’s active biorhythm.

The Sun’s 11-year cycles of activity range from a low ebb to robust periods, producing explosive events such as highly charged particle ejections and coronal mass ejections, which are major drivers of dangerous space weather.

Inside the Sun

Below the solar surface, processes generate the Sun’s magnetic field, which drives the solar cycles, which in turn drive space weather. Space weather can be extremely hazardous to the electronic and communications infrastructure we rely on, both in space and on Earth’s surface, including GPS systems and the power grid. Therefore, as our reliance on that infrastructure grows, accurately predicting space weather has become an increasingly important concern.

Scientists have primarily used external markers, such as sunspots, to track solar activity, but, like in any system, much of what drives the Sun occurs beneath the surface. To pierce the solar veil, the researchers have adopted a technique called helioseismology, which allows them to listen to small sound waves from inside the Sun. These waves reveal minute changes beneath the surface, providing a very different understanding of the most recent solar cycles than what could be observed from external markers.

A History of the Sun

The research relied on nearly four decades of helioseismic data collected by the Birmingham Solar Oscillations Network (BiSON) of six telescopes located around the globe. Finally, researchers had sufficient historical data on the Sun’s inner workings to conduct a lengthy study of how these workings have changed over time.

In their analysis of that data, the international team identified a slow but growing change in the structure of the Sun’s interior, occurring across multiple cycles.

“The Sun has its own ‘active biorhythm’ creating rising and falling magnetic activity that shapes space weather,” said lead author Professor Bill Chaplin, from the University of Birmingham. “However, traditional surface measures don’t capture the full story – that the Sun may be entering a different mode of behavior unfolding over decades.”

“We have uncovered evidence of systematic changes in the solar activity cycle,” Chaplin added. “Crucially, magnetic activity is becoming more tightly confined near the surface with each cycle. This is the first such discovery and would have been impossible without the long BiSON observations.”

A Deeper Look

From 1987 through 2025, during cycles 22-25, shifts in p-mode oscillations driven by magnetic activity revealed internal changes in the Sun. The team identified three different groups of oscillations, marked by the low, medium, and high-frequency bands, each penetrating the solar surface to a different depth. Compared with traditional external markers, the data revealed three unique elements. 

Since cycle 23, oscillation frequencies and external markers have begun telling very different stories, indicating major changes in the Sun’s internal workings. As time goes on, more and more of the changes are occurring near the surface, at depths of less than 1,000 kilometers. In the most recent cycle, 25, helioseismic data are giving off much stronger indications of this activity than surface markers.

According to the researchers, weakening magnetic fields cannot account for the changes observed, suggesting a major structural reorganization beneath the Sun’s surface. 

The team says that continuing exploitation of the BiSON data into cycle 26 will be essential to determining whether this indicates a sustained change in solar activity. 

The paper, “Sub-Surface Structural Changes Associated with Successive 11-yr Solar Activity Cycles Have Been Progressively More Confined Near the Surface: New Helioseismic Results on Cycles 22– 25 from BiSON,” appeared in Monthly Notices of the Royal Astronomical Society on May 28, 2026.

Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.

A mysterious weather anomaly on Venus has finally been explained in new research, providing deeper insights into the weather volatility of other planets in our solar system.

University of Tokyo researchers revealed their findings in a recent paper published in the Journal of Geophysical Research, focused on their investigation of a massive cloud disturbance observed on the second planet from the Sun.

This unusual cloud phenomenon involves a 6,000-kilometer-wide wave front that travels around Venus over just a few Earth days, and scientists believe it could potentially affect future space missions.

A Weather Aberration on Venus

Japan’s Akatsuki Venus orbiter first observed Venus’s enormous, 6,000-kilometer-wide atmospheric wave move across the planet’s equator at tremendous speed in 2016. Now, a decade later, the University of Tokyo team has some answers about this peculiar feature.

Compared to Earth, Venus is a slow mover, with its rotation even slower than its 243-day orbit. Despite this, Venusian clouds move at an incredible pace, 60 times the planet’s rotational speed in what is known as “superrotation,” a phenomenon also observed on Mars, the Sun, and Earth’s supersonic atmosphere.

“We identified the phenomena, but for years we couldn’t understand it,” said lead author Professor Takeshi Imamura from the Graduate School of Frontier Sciences at the University of Tokyo. “However, thanks to this research, we’re now able to show that this cloud disruption is caused by the largest known hydraulic jump in the solar system.”

A Natural Weather Lab

The Venusian atmosphere is hot, dense, and toxic, being composed of almost 97% carbon dioxide. This results in constant cloud cover, which rains sulfuric acid. While this creates a deadly environment for humans, at a distance, it’s a perfect natural weather laboratory. This extreme cloud density makes hard-to-spot weather patterns and processes more readily apparent than they would be on a planet such as ours.

The strange formation in the Venusian atmosphere resulted from a sudden slowdown of the fluid, known as a hydraulic jump, produced when a large atmospheric Kelvin wave moving east across Venus becomes unstable in the lower to middle cloud region. The Kelvin wave’s sudden slowing produces an updraft, pushing sulfuric acid vapor into the upper atmosphere, where it can condense into clouds. As though clouds trail, they form the enormous wavefront spotted by Akatsuki Venus.

“Venus has three distinct cloud layers, and the dynamics of the lower and middle layers are not so well understood,” said Imamura. “Our discovery of a hydraulic jump on Venus connecting a very large-scale horizontal process with a strong localized vertical wave is unexpected, as in fluid dynamics these are usually disconnected.”

Analyzing Venusian Weather

The Japanese researchers used a fluid-dynamic model to simulate the hydraulic jump observed on Venus, combined with a microphysical box model to track air flow through the atmosphere. In their analysis, the University of Tokyo researchers identified how the cloud disturbance maintains the Venusian atmosphere’s superrotation.

“Up until now, we used a global circulation model (GCM) for Venus that is similar to Earth’s, but this model doesn’t include the hydraulic jump which we have now identified,” explained Imamura. “Our next step will be to test this discovery within a more inclusive climate model that includes other atmospheric processes. We will face challenges due to the significant processing power required to run such simulations. Even with modern supercomputers, it isn’t easy.”

This marks the first hydraulic jump observed on another planet, but the researchers say this may be a portent of things to come as scientists get a closer look at other bodies in the universe. 

“Under some circumstances, Mars’ atmosphere may also have the right conditions for a hydraulic jump,” mentioned Imamura. 

As humanity stretches out into space with hopes of crewed Mars landings in the coming decades, advancing models of extraterrestrial atmospheric conditions will be essential to mission safety.

The paper, “A Planetary-Scale Hydraulic Jump Driving Venus’ Cloud Front,” appeared in the Journal of Geophysical Research on April 24, 2026.

Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.