1. Solar Wind Model at LMSAL AIA/HMI Science Team Meeting Session S3 15 February 2006 Marc DeRosa

2. Evolving Surface-Flux Model Basic principle: All magnetic flux on the model surface is subject to transport by differential rotation, meridional flows, flux-dependent random-walk dispersal. Basic principle: All magnetic flux on the model surface is subject to transport by differential rotation, meridional flows, flux-dependent random-walk dispersal. When available, MDI line-of-sight magnetogram data is assimilated into the flux-transport model. When available, MDI line-of-sight magnetogram data is assimilated into the flux-transport model.

3. Potential Field Extrapolation Full-surface magnetic field data is then used as a lower boundary condition for the potential field source surface (PFSS) model of the coronal magnetic field. Full-surface magnetic field data is then used as a lower boundary condition for the potential field source surface (PFSS) model of the coronal magnetic field. PFSS model provides magnetic field between photosphere and the source surface located at R SS = 2.5 R sun. PFSS model provides magnetic field between photosphere and the source surface located at R SS = 2.5 R sun. By definition, PFSS model contains no currents, but it compares well with large-scale EUV loops, and locations of coronal holes. By definition, PFSS model contains no currents, but it compares well with large-scale EUV loops, and locations of coronal holes.

4. Quiescent Solar Wind Model A ballistic solar wind model is then used to determine the solar wind speed throughout interplanetary space. A ballistic solar wind model is then used to determine the solar wind speed throughout interplanetary space. Solar wind streams are given a velocity at R SS dependent on the base field strength of each ecliptic fieldline. Solar wind streams are given a velocity at R SS dependent on the base field strength of each ecliptic fieldline. Streams are then allowed to interact as they pass through the heliosphere. Streams are then allowed to interact as they pass through the heliosphere. (The potential nature of the coronal field precludes the modeling of transients.) (The potential nature of the coronal field precludes the modeling of transients.) top-down view of ecliptic plane showing wind speeds and polarities

5. Forecasting Efforts Allowing the surface field to evolve in time past the current date enables us to forecast the quiescent wind. Allowing the surface field to evolve in time past the current date enables us to forecast the quiescent wind. wind forecast ACE measurement sector boundaries

6. Forecasting Efforts Time-space plot of base field strength illustrates one source of uncertainty in the wind forecast. Time-space plot of base field strength illustrates one source of uncertainty in the wind forecast. PAST FUTURE

7. Some Final Thoughts Current model is affected by: Current model is affected by: incomplete physics (e.g. no transients) incomplete physics (e.g. no transients) incomplete knowledge of magnetic fields on sides/back/poles incomplete knowledge of magnetic fields on sides/back/poles calibration issues, especially saturation of MDI in strong fields calibration issues, especially saturation of MDI in strong fields lack of knowledge of stream-stream interactions and deflections between sun and 1 AU lack of knowledge of stream-stream interactions and deflections between sun and 1 AU no particles no particles