SBIR-STTR Award

Solar active regions have a major impact on space weather. Knowledge of active regions in the Sun’s far hemisphere can improve forecasts of impending solar storms and future UV irradiance variations that negatively impact spacecraft, communications, and navigation facilities, thus making knowledge of active region locations and strengths of great benefit to society. We will use algorithms based on seismology of acoustic waves in the Sun to monitor the Sun’s far hemisphere: computational seismic holography and time-distance tomography. We will develop a large-active-region discriminator, capable of partitioning seismic signatures into simple individual elements for the purpose of identifying and characterizing the far-side active regions. For the Phase I study, primary emphasis will be on validating the helioseismic assessment of the locations, strengths, and growth rates of active regions in the Sun’s far hemisphere in terms of stability and consistency over a 5-year period. Based upon these results, we will develop plans for a Phase II project to make synoptic seismic monitoring of the Sun’s far hemisphere a crucial role of helioseismic observatories in space weather forecasting in the twenty-first century.

Magnetic regions in the Sun’s outer atmosphere exert major impacts on space weather in the near-Earth environment. Near-term impacts at Earth are predominantly due to magnetic regions in the Sun’s near hemisphere; however, because the Sun rotates, mag- netic regions in the far hemisphere cross into the near hemisphere with little warning—except for our ability to monitor the Sun’s far hemisphere from vantages in the helio- sphere other than that of Earth. For the past several years NASA’s twin STEREO spacecraft have been in positions to view the entirety of the far hemisphere from the far side of the solar system. We are now approaching a period of most of a decade in length during which STEREO coverage of the Sun’s far hemisphere will be greatly diminished or nil. We have developed algorithms capable of analyzing seismic observations of the Sun’s near hemisphere to map large active regions with full coverage of the Sun’s far hemisphere. We propose to use these algorithms to produce a data product of synoptic seismic maps of the Sun’s far hemisphere that can take over the role of STEREO in the service of our nation’s space-weather forecasting needs.