Solar Flare Irradiance: Observations and Physical Modeling

Abstract We examine Solar Dynamics Observatory (SDO)/EUV Variability Experiment (EVE) data to better understand solar flare irradiance, and how that irradiance may vary for large events. measure scaling laws relating Geostationary Orbital Environmental Satellites (GOES) classes in 21 lines measured with SDO/EVE, formed across a wide range of temperatures, find this depends on the line-formation temperature. extrapolate these values events, exceeding X10. In order create full spectra, however, we need physical model irradiance. present first results new NRLFLARE, sums together series loops calculate spectral ranging from X-rays through far-UV (?0 1250 Å), constrained only by GOES/X-ray Sensors observations. test against SDO/EVE data. The spectra time evolution compares well high-temperature emission, but cooler show discrepancies. speculate discrepancies are likely due both nonuniform cross-section flaring as opacity effects. then allowing cross-sectional area height significantly improves agreement observations, is therefore crucial parameter needed accurately intensity lines, particularly transition region 4.7 ? log T 6 .