ESA's SMOS and Swarm Satellites Uncover the Magnitude of a Solar Storm's Impact on Earth

ESA's SMOS and Swarm Satellites Uncover the Magnitude of a Solar Storm's Impact on Earth
by Erica Marchand
Paris, France (SPX) Mar 27, 2024

Over the recent weekend, a significant celestial event unfolded as the Sun unleashed an extraordinary amount of electromagnetic radiation towards Earth. This solar activity not only produced the awe-inspiring aurora borealis, lighting up the night sky in a dazzling display of colors but also brought to the forefront the capabilities of the European Space Agency's (ESA) two unassuming satellites: SMOS and Swarm. Together, these satellites embarked on a new mission to track and analyze the effects of this substantial solar storm on Earth's magnetic field, marking a pivotal moment in space weather observation.

Solar weather phenomena, including electromagnetic radiation and particles such as solar flares and coronal mass ejections (CMEs), have always held a place of fascination and concern within the scientific community and the general public alike. While the phenomenon contributes to creating the stunning visual spectacle known as auroras, it also harbors the potential to disrupt modern technology. From satellites orbiting our planet to the intricate networks of communication and power grids that crisscross the continents, the impact of solar weather can be far-reaching and multifaceted.

The Solar Flare of 23 March 2024
The event that drew the global attention of scientists and aurora enthusiasts alike began on 23 March 2024, with the Sun emitting a powerful X1.1 class solar flare. Originating from an active sunspot directly facing Earth, this flare was followed closely by a coronal mass ejection (CME), setting a course directly towards our planet. This development placed the scientific community on high alert due to the potential ramifications of such a direct hit.

Swarm Satellites' Response to the Solar Event
The Swarm satellite constellation, specifically designed to monitor variations in Earth's magnetic field, found itself at the forefront of this celestial event. Each satellite within the constellation is equipped with a magnetometer, enabling precise measurements of magnetic field strength. These instruments were crucial in detecting the changes brought about by the incoming CME, which arrived earlier than anticipated on the afternoon of 24 March. This early arrival precipitated a geomagnetic storm of severe intensity, providing a unique opportunity to put Swarm's near-real-time data capabilities to the test.

Swarm Alpha was the first to detect the geomagnetic disturbances, with Swarm Bravo and Charlie providing complementary data. The information collected offered unprecedented insights into the alterations within Earth's magnetic field at both high and lower latitudes. Despite the storm's relatively short duration, its intensity and the significant perturbations it caused in the magnetic field have been a subject of ongoing analysis and study within the scientific community.

SMOS Satellite's Unexpected Role
Perhaps one of the more surprising developments was the involvement of ESA's Soil Moisture and Ocean Salinity (SMOS) satellite in monitoring the solar event. Known primarily for its role in measuring Earth's soil moisture and ocean salinity, SMOS found itself in a unique position to capture the solar radio burst associated with the flare, thanks to its Miras interferometer radiometer. This instrument, which typically detects 'L-band' radio waves emitted from Earth, inadvertently became a tool for space weather observation.

The solar flare's radio emissions, normally considered noise in Earth observation data, were instead utilized by space weather scientists to glean valuable insights. The real-time monitoring capabilities of SMOS provided critical data on the solar flare's impact on global navigation satellite systems (GNSS), as well as on flight radar and L-band communications. This unexpected application of SMOS data highlighted the satellite's versatility and its potential for contributing to space weather research.

Collaborative Efforts Enhance Space Weather Understanding
The collaborative efforts of the SMOS and Swarm missions in monitoring this solar storm have not only demonstrated the capabilities and adaptability of ESA's Earth Explorer satellites but have also significantly advanced our understanding of space weather dynamics. As the Sun continues its march towards the solar maximum expected in 2025, the insights gained from these missions will be invaluable. The increasing solar activity anticipated in the lead-up to the solar maximum underscores the importance of continued and enhanced monitoring of space weather phenomena.

The Future of Space Weather Monitoring
Looking ahead, ESA's commitment to advancing our understanding of space weather and its impacts on Earth is exemplified by the planned launch of the Vigil mission in 2031. This mission aims to provide early warnings of solar activity by monitoring the Sun's side not currently visible from Earth. By increasing the lead time for space weather forecasts, Vigil promises to enhance our preparedness for and resilience against the potential hazards posed by solar storms.

The remarkable collaboration between ESA's SMOS and Swarm satellites in tracking and analyzing the recent solar storm serves as a testament to the critical role of space weather observation in our increasingly technologically dependent society. As we continue to unravel the complexities of solar-terrestrial interactions, missions like SMOS, Swarm, and the future Vigil will be instrumental in safeguarding our planet's technological infrastructure against the unpredictable nature of space weather.