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Driving Models of the Solar Corona Using Photospheric Observations

Event Details

Event Dates: 

Thursday, April 4, 2013 - 4:00pm

Seminar Location: 

  • JILA Auditorium

Speaker Name(s): 

Brian Welsch

Speaker Affiliation(s): 

Space Sciences Laboratory, University of California, Berkeley
Seminar Type/Subject

Scientific Seminar Type: 

  • Astrophysical & Planetary Sciences Seminar

Event Details & Abstract: 

Solar flares and coronal mass ejections (CMEs) are driven by the release of magnetic energy stored in electric currents in the coronal magnetic field. Given the corona's high Alfven speed (compared to that at the photosphere) and low diffusivity, the large-scale coronal field could rapidly obtaining near-equilibrium without photospheric forcing. Consequently, photospheric evolution plays a central role in the injection, storage, and release of coronal magnetic energy. But fundamental questions about each stage of this "storage and release" flare paradigm remain open: How does magnetic energy build up in the corona? Where is this energy stored? And what triggers its release? The unprecedented combination of high cadence, resolution, and duty cycle of the Helioseismic and Magnetic Imager (HMI) vector magnetograph enables modeling coronal magnetic evolution in response to photospheric driving, a powerful approach to addressing these questions. I will describe efforts to use HMI vector magneotgrams of NOAA AR 11158 to derive time-dependent boundary conditions for data-driven coronal magnetic field models. These efforts will play a key role in development of the Coronal Global Evolutionary Model (CGEM), a five-year project to create a data-driven, time-dependent model of the global coronal field, recently selected for funding by NASA's Living With a Star program and NSF's Division of Atmospheric and Geospace Sciences.