April 8 total solar eclipse reveals changes in the Sun’s corona and Earth’s atmosphere

At the American Geophysical Union (AGU) meeting in Washington, D.C., on December 10, researchers presented early results from experiments on the total solar eclipse on April 8 by the National Aeronautics and Space Administration (NASA).

This total solar eclipse spanning 18 000 km (11 185 miles), spanning from Mexico to Canada in North America, offered unparalleled opportunities for studying solar-terrestrial interactions. Research teams focused on corona behavior, ionospheric responses, and atmospheric changes collecting data for advancing heliophysics.

Observable transformations in the Sun’s Corona

During the April 8 eclipse, the Sun’s corona displayed noticeable structural changes and variations in electrified plasma temperatures.

The Citizen CATE 2024 project captured over 47 000 images using polarized light and documented transitions in the corona’s magnetic field and plasma flow patterns. The project is compiling these images into an hour-long movie. The movie is expected to be released in mid-2025, to provide a visual analysis of these phenomena.

“The beauty of CATE 2024 is that we blend cutting-edge professional science with community participants from all walks of life,” Sarah Kovac project manager at the Southwest Research Institute, said.

“The dedication of every participant made this project possible.”

High-altitude NASA WB-57 aircraft observed the corona in Fe XIV wavelengths capturing plasma at approximately 1.8 million °C (3.2 million °F). Instruments documented intricate arch-like structures within the corona though some images were blurred because of unexpected wing vibrations. Despite this spectrometers provided high-fidelity data.

“The WB-57 is a remarkable platform for eclipse observations that we will try to capitalize on for future eclipses,” Shadia Habbal of the University of Hawaii, said.

Atmospheric responses to totality (complete eclipse phase)

During the totality phase of the eclipse, when the Moon completely covered the Sun, citizen radio operators engaged in the HamSCI observed ionospheric shifts.

Data analysis from over 52 million observations showed that radio signal absorption decreased at frequencies between 1 and 7 MHz which led to improved communication during the eclipse.

Frequencies above 10 MHz experienced disruptions.

The analysis confirmed that the ionosphere temporarily ascended during the eclipse returning to its normal state afterward.

“The project brings ham radio operators into the science community,” Nathaniel Frissell professor at the University of Scranton.

“Their dedication to their craft made this research possible.”

Tropopause and atmospheric gravity waves

High-altitude balloon data from the Nationwide Eclipse Ballooning Project documented ripples in the atmosphere known as gravity waves caused by the eclipse. Instruments recorded disturbances in the tropopause similar to atmospheric effects observed during sunsets.

“Half of the teams had little to no experience ballooning before the project. But their hard work and research were vital in this finding,” Jie Gong atmospheric scientist at NASA’s Goddard Space Flight Center noted.

These findings aligned with earlier theories suggesting that gravity waves are generated in the atmosphere from rapid temperature and pressure shifts triggered by sudden cooling during an eclipse.

A collective effort

More than 36 000 volunteers contributed to NASA’s eclipse research projects including SunSketcher and GLOBE Observer. These citizen scientists collected 60 000 data points such as temperature variations and solar phenomena demonstrating the value of collaborative science.

As NASA’s Heliophysics Big Year continues through December 2024, further analyses of the collected data promise deeper insights into the intricate dynamics of the Sun’s influence on Earth.

References:

¹ Scientists Share Early Results from NASA’s Solar Eclipse Experiments – NASA – December 10, 2024

Rishika Yadav

Rishika holds a Master’s in International Studies from Stella Maris College, Chennai, India, where she earned a gold medal, and an MCA from the University of Mysore, Karnataka, India. Previously, she served as a Research Assistant at the National Institute of Advanced Studies, Indian Institute of Science, Bengaluru, India. During her tenure, she contributed as a Junior Writer for Europe Monitor on the Global Politics website and as an Assistant Editor for The World This Week. Her work has also been published in The Hindu newspaper, showing her expertise in global affairs. Rishika is also a recipient of the Women Empowerment Award at the district level in Haryana, India, in 2022.

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