1. 1 Solar Radiation Physical Modeling (SRPM) J. Fontenla June 30, 2005b

2. 2 Emitted SpectraRadiative Losses Mean Intensity and Net Radiative Brackett Radiative Transfer Non-LTE Atmospheric Parameters Continua Molecular Lines Atomic Lines Molecular Continua Populations & Ionization Populations & Ionization Balance Momentum & Energy Balance Atomic Data Molecular Data

3. 3 Critical Next Steps Adjust photospheric models and abundances –Low first-ionization-potential (FIP) contribute to ne and photospheric opacity –High FIP are needed for upper layers Re-think lower chromosphere –Account for radio data showing Tmin<4200 K –Account for UV continua from SOHO-SUMER showing high Tmin –Account for molecular lines (CN, CH, CO) showing low Tmin Re-think upper chromosphere with current abundances and observations Re-compute transition region with updated abundances, atomic data, diffusion and flows, and energy-balance MHD, full-NLTE, 3D simulations of chromospheric variations Prominence eruptions-CMEs

4. 4 Low Chromosphere Issues Fe & C abundance seem good But computed CN lines are not good. Are abundances incorrect? Or is the model chromosphere incorrect? C I line

5. 5 H Ionization and Ly Alpha Line

6. 6 V1.5 Ly  Computed Profiles Continuum too high due to Sulphur continuum Not enough contrast for faculae and plage Umbra profile has reversal unlike the observed

7. 7 Trace Species Ionization For each species and ionization stage Or split the abundance and ionization

8. 8

9. 9 Chromospheric Magnetic Heating Mechanism Farley-Buneman Threshold Term B U, J Hall E,J Ped U thr =C s (1+ψ)

10. 10 Prominence-Eruption-CME 3-D non-LTE radiative transfer & MHD modeling Instrumentation for observing Doppler spectra, spatial- and temporal-evolution