July 16: In a groundbreaking discovery, Indian astrophysicists have decoded the extraordinary solar activity that turned Ladakh’s skies into a celestial canvas of northern lights in May 2024. The phenomenon, caused by a rare chain of six powerful Coronal Mass Ejections (CMEs) from the Sun, resulted in one of the strongest geomagnetic storms in two decades, researchers revealed.
CMEs are massive eruptions of magnetized plasma from the Sun’s outer layer, known as the corona. When directed toward Earth, they can trigger geomagnetic storms capable of disrupting satellites, communications, and power grids. The May 2024 storm, which began on 10th May, was exceptional—not just for its intensity but for its complexity. Scientists linked it to six interacting CMEs erupting in quick succession, each associated with solar flares and filament eruptions from a dynamic active region on the Sun.
For years, understanding the thermodynamic evolution of CMEs during their journey from the Sun to Earth has been a challenge due to limited observations. To bridge this gap, a research team led by Dr. Wageesh Mishra from the Indian Institute of Astrophysics (IIA) used data from NASA and ESA missions, alongside observations from IIA’s Indian Astronomical Observatory in Hanle, Ladakh.
Using a novel analytical framework called the Flux Rope Internal State (FRIS) model, the team traced the CMEs’ paths, magnetic states, and temperature changes across interplanetary space. Their findings were striking: these solar storms do not behave thermally as expected. Initially, CMEs released heat, but later entered a state where they absorbed and retained energy, stabilizing at near-constant temperatures as they expanded away from the Sun.
Even more surprising, near-Earth observations from NASA’s Wind spacecraft revealed a double flux rope structure—two interwoven magnetic fields within the final CME, behaving like tangled magnetic braids. This interaction led to unusual heating and cooling patterns, with electrons releasing heat while ions showed mixed thermal behaviors.
“This is the first study, both in India and globally, to capture continuous thermodynamic changes in multiple interacting CMEs over such vast distances,” said Soumyaranjan Khuntia, lead author and doctoral scholar at IIA. Published in Astronomy and Astrophysics Journal, the research marks a major advance in space weather forecasting, offering hope for predicting geomagnetic storms that threaten satellites and critical infrastructure.
The team now plans to integrate data from India’s Aditya-L1 solar mission, including instruments like the Visible Emission Line Coronagraph (VELC) and ASPEX, to enable complete Sun-to-Earth tracking of CME events.
As scientists continue decoding these cosmic tempests, one thing is clear: understanding the Sun’s fiery outbursts is key to safeguarding our planet in the era of space-dependent technology.
