Quantifying helioseismic measurements of solar magnetic fields with laboratory experiments and simulations

The National Science Foundation Office of Integrative Activities awarded $539,747 to the Space Science Institute on August 1, 2026, under the Geosciences program (CFDA 47.050) to develop a method for producing maps of surface magnetic fields on the far side of the sun using helioseismic measurements.

The project will conduct laboratory experiments to understand acoustic and magnetoacoustic waves that propagate inside the sun, developing the first global magnetoacoustic model (GALE+) that incorporates magnetic field effects. Experimental results will refine existing wave propagation models and quantify measurement uncertainties. The team will apply existing observational helioseismic techniques to these simulations to measure and characterize the uncertainty associated with the measurement methods themselves, enabling creation of the first far-side solar surface magnetic field maps with well-defined error estimates. These maps will provide more complete information for space weather forecasting. All magnetic field maps, computational models, and underlying data will be made available to other researchers.

The work is led by early career researchers and includes a public engagement component to expand heliophysics reach within the research community and broadly.

Performance period runs from August 1, 2026, through July 31, 2029, with work performed in Boulder, Colorado.

Abstract

This project will develop a new method for producing maps of surface magnetic fields on the far side of our sun. Accurate maps are critical for improving predictions of space weather events that could affect humans and technology on earth and in space. Laboratory experiments will be used to better understand the waves that propagate inside the sun; experimental results will be used to refine existing models and create the first ever computational model of these waves that includes the effects of magnetic fields. Existing observational techniques will be applied to these wave simulations in order to measure the uncertainty associated with these measurement techniques. Known uncertainties will enable creation of the first maps of far-side surface magnetic fields with well-defined error estimates, providing more complete information for space weather forecasting. The magnetic field maps, new computational model, and all data will be made available to other researchers. This effort will be led by early career researchers who will expand the reach of heliophysics, both within the research community and through significant public engagement. This project develops a new method for producing maps of photospheric magnetic flux on the solar far-side using global helioseismology, informed by detailed laboratory experiments and new simulation capabilities. The work includes the first ever detailed laboratory tests of conversion between acoustic and magnetoacoustic modes predicted by MHD theory and development of the first global magnetoacoustic model (gale+). Wave behavior in the new model will be compared to both physical and empirical equations tested in the laboratory experiments. Laboratory results also provide a new, more detailed lens for helioseismologists to interpret wave travel time shifts. The far-side time-distance helioseismic technique will be tested on simulated far-side magnetic flux maps to quantify the uncertainty associated with far-side helioseismic detections for the first time. The interdisciplinary nature of the proposed work will bridge the GAP between laboratory, theoretical, simulated, and observed solar plasma physics. The project will produce improved daily maps of estimated far-side photospheric magnetic flux, including quantitative magnetic characterizations of newly-emerged, growing or decaying active regions. These new maps will provide a more accurate inner boundary condition to drive coronal and heliospheric models and improve space weather forecasting capabilities. The gale+ model can be a testbed for validating global helioseismic techniques on physics-based simulations. The magnetic flux maps, gale+ simulations, and data will be published and made available for the community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are planned for this award.