The Expanded Owens Valley Solar Array as a Community Facility

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Solar flares and active regions in the solar atmosphere represent two phenomena that are key to better understanding of initiation mechanisms of solar activity. The evolving magnetic fields power explosive releases of the solar energy, and their measurements are therefore of utmost importance for understanding and forecasting of solar activity that impact the Earth and near-Earth space environment (Space Weather). The work will support operations and research conducted at the Expanded Owens Valley Solar Array (EOVSA). EOVSA is the US sole solar-dedicated radio facility with the capability to provide routine spectral imaging of the solar activity and directly measure the solar magnetic fields in 3D. The recently passed bipartisan PROSWIFT Act (Promoting Research and Observations of Space Weather to Improve the Forecasting of Tomorrow) calls, among other things, for "sustaining ground-based observational capability" including "maintain and improve ground-based observations of the Sun." The work directly addresses this call by providing solar radio data during the rising phase of Solar Cycle 25. This work will also develop the mathematical framework to deduce information about solar environment from the currently unutilized polarized data, which will provide key information for both active region structure and theoretical understanding of particle acceleration in solar flares. Further, this project will improve image reconstruction techniques by more accurately accounting for differential solar rotation, which will greatly enhance the capability to image solar flares and active regions. This project will stimulate integration of research and education by directly supporting several graduate students at the New Jersey Institute of Technology and the University of California Berkeley who will be responsible for EOVSA operations on a rotating basis as well as develop STEM workforce by supporting and involving students and early-career postdoctoral researcher.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.