Team produces first 3D map of the Sun’s coronal magnetic field

A research team produced the first global three-dimensional map of the Sun’s coronal magnetic field, extending beyond the visible solar disk into nearby space. The Astrophysical Journal Letters published the findings on Oct. 28, 2026.

The paper, “A First Global Full-vector Coronal Magnetic Field Inference Using MLSO CoMP and UCoMP Observations,” by Alin Razvan Paraschiv et al., appeared under DOI 10.3847/2041-8213/aead9e. The authors describe the result as a shift from a theoretically proven method to an observationally proven capability. They caution that the first maps are still limited and need more development and validation before routine use.

For decades, researchers could observe the structure of the Sun’s corona, but they previously lacked measurements of the entire magnetic field that shapes it. The team applied a new technique on existing Mauna Loa Solar Observatory data to close that observational gap. The U.S. National Science Foundation National Center for Atmospheric Research runs the observatory. Researchers studied the corona’s structure for decades while lacking a full measurement of its shaping magnetic field, so this result fills a long-standing observational gap using existing observatory data instead of new hardware.

Instead of gathering fresh observations, the team drew on archived CoMP observations from Oct. 14, 2016, and UCoMP observations from June 1, 2022. They pulled wave-encoded information from the corona and used it to rebuild the three-dimensional coronal magnetic field. The work recovered magnetic information encoded in coronal waves using archived data from two instrument versions. No new observations were collected for the reconstruction.

The research group drew on NSF NCAR, the National Solar Observatory, and Southwest Research Institute, and the National Science Foundation funded the research. The National Science Foundation supports the National Solar Observatory. Alin Paraschiv, an NSF NSO researcher and the paper’s lead author, said humanity can now see the Sun’s hidden magnetic structure in three dimensions by reading coronal light and waves rather than building new instruments. He tied the work to the solar wind and auroras and said viewing the Sun’s hidden magnetic architecture in three dimensions could transform scientific understanding of the star.

Daniela Lacatus, an NSF NCAR researcher and paper co-author, said the method produced the first measurements of coronal magnetic-field strength and direction in three dimensions for regions covered by MLSO observations, ending a decades-long bottleneck. She added that validation results looked reasonable and met expectations, and that others were excited about the work. She described the earlier measurement gap as a major bottleneck.

Lacatus said, “These results help to overcome a major bottleneck in measuring the coronal magnetic field that has persisted for decades.” She said the team hopes the community will test and refine the approach because it works and needs broad availability.

Earlier work produced the first global coronal magnetic-field maps in two dimensions using UCoMP at MLSO, and another study introduced the IQUD inversion following theoretical and statistical testing. Mauna Loa Solar Observatory’s CoMP and UCoMP data are public. Using the IQUD inversion, researchers can create three-dimensional coronal maps on any day that has suitable observations from either instrument. The method does not require fresh observations, but usable observations must exist for any given day.

Paraschiv’s method is openly available. Operational observatory pipelines do not yet carry it as a data product. The team hopes the method becomes a standard product for the advanced COSMO observatory network. The team published its analysis software and data sets and asked other scientists to test, refine, and extend the technique.

The work aims to improve solar-activity models and forecasts of solar magnetic eruptions that drive extreme space weather affecting critical infrastructure on Earth. The source calls solar magnetic eruptions the underlying cause of extreme space weather, which can damage critical Earth-based infrastructure. Satellite operators and power-grid managers would benefit from better eruption forecasts. The work marks progress toward better solar-activity models and eruption forecasts.

Tom Berger, the MLSO director, described the observatory data as a pathfinder for better solar-eruption forecasts. He said the planned COSMO coronagraph network will replace MLSO, produce new magnetic-field observations, and close a major gap in monitoring space weather. Berger tied the finding to the future COSMO network and said the advanced coronagraph network would close a major observational gap for space-weather drivers. The network would succeed the current Mauna Loa Solar Observatory.