1. A 3D-MHD Model Interface Using Interplanetary Scintillation (IPS) Observations B.V. Jackson 1, H.-S. Yu 1, P.P. Hick 1, A. Buffington 1, D. Odstrcil 2, T.K. Kim 3, N.V. Pogorelov 3, C.-C. Wu 4, M. Tokumaru 5, J. Kim 6, and S. Hong 6 Abstract We at UCSD for over two decades have developed a remote-sensing iterative time-dependent three- dimensional (3D) tomographic reconstruction technique which provides volumetric maps of density, velocity, and magnetic field. These extend from an inner boundary out to nearly the whole inner heliosphere. This modeling requires a “traceback” to the boundary, from any element within the heliospheric volume, which specifies the element origin, time, and change from a 2D location on a set of Carrington maps. Moreover, this process has recently included a traceback from any input volume to yield an updated boundary in velocity, density, temperature, and magnetic field components, based on fitting to data from interplanetary scintillation (IPS) or other remotely- sensed heliospheric measurements. This traceback from an external volume is the most difficult step needed to implement a future UCSD iterative tomographic analysis from any given solar-wind model. Up to now, the iterative UCSD tomographic analysis (fitting STELab, Japan, IPS data) has used an internal solar wind model that conserves mass and mass flux, and as a first step allows an inner boundary to be extracted to drive heliospheric 3D-MHD (magnetohydrodynamic) forward models. Here, three examples are shown where this IPS inner boundary has been used in this way: 1) Analysis of the 2014 September 9-10 halo coronal mass ejections (CMEs) using the ENLIL 3D- MHD code at Earth and at the Rosetta spacecraft situated at 3.7 AU; 2) Analysis of the period during two halo CMEs on 2011 September 24 using the UAH MS-FLUKSS 3D-MHD heliospheric code; 3) Analysis of the 2015 March 15 halo CME and its associated three component magnetic fields with the NRL H3D-MHD code. The UCSD time-dependent Computer-Assisted Tomography program uses the outward motion of structures and an outward-changing weight along the LOS to provide global time-varying 3D reconstructions. So far, this time-dependent reconstruction technique has incorporated a purely kinematic solar wind model that enforces conservation of mass and mass flux and assumes radial outflow (Jackson et al., 2008). The LOS segment 3D weightings are projected back in space and time using a programming algorithm we term a “traceback matrix” to a solar wind inner boundary reference surface (sometimes also called the "source surface") that is usually set at 15 solar radii (Rs). 1. The UCSD Time-Dependent Tomography Analysis IPS weighting response with distance from Earth 1 Center for Astrophysics and Space Sciences, University of California, San Diego, 1 Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, USA E-Mail: bvjackson@ucsd.edu Tel: 858-534-3358 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, USA E-Mail: bvjackson@ucsd.edu Tel: 858-534-3358 2 George Mason University, 4400 University Drive, Fairfax, VA 22030, USA, and NASA/GSFC M/C 674, Greenbelt, MD 20771, USA 3 Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville (UAH), Huntsville, AL, USA 4 Naval Research Laboratory (NRL), 4555 Overlook Ave., Washington, DC 20375, USA 5 Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan 6 Korean Space Weather Center, National Radio Research Agency, 198-6, Gwideok-ro, Hallim-eup, Jeju, 695-922, South Korea Lines of sight traced back from their location in space to the source surface at two given times 2000 July 14 2000 July 13 In the traceback matrix as used in the UCSD kinematic model, the location of the upper level data point (starred) is an interpolation in x of Δx 2 and the unit x distance - Δx 3 distance or (1 - Δx 3 ). Similarly, the value of Δt at the starred point is interpolated by the same spatial distance. Each 3D traceback matrix contains a regular grid of values ΣΔx, ΣΔy, ΣΔt, ΣΔv, and ΣΔm that locates the origin of each point in the grid at each time and its change in velocity and density, etc. from the heliospheric model. Traceback matrix concept in 2D 2. IPS Global Solar Wind Boundaries Interpolation from the kinematic IPS tomography model provides sample inner boundaries of (a) density, (b) velocity, and (c) radial and (d) tangential magnetic field for ENLIL extracted in Earth- centered Heliographic Coordinates at 0.1AU using STELab IPS observations and NSO SOLIS magnetograms (see Yu et al., 2015). Zeeman splitting provides vertical magnetic fields at the solar surface using the Current Sheet Source Surface (CSSS: Zhao and Hoeksema, 1995) model to give accurate vertical fields at a source surface. These fields are extrapolated outward using the global velocity model derived by the IPS to provide radial and tangential field components (in RTN coordinates) anywhere within the volume. *

2. (http://ips.ucsd.edu/) (ftp://cass185.ucsd.edu/data/IPSBD_Real_Time/) Real-Time IPS forecasting (http://ips.ucsd.edu/), IPS ENLIL Boundary (ftp://cass185.ucsd.edu/data/IPSBD_Real_Time/) (http://helioweather.net/models/ipsbd/den1r2e4b/index.html) and a Real-Time IPS Boundary-Driven ENLIL (http://helioweather.net/models/ipsbd/den1r2e4b/index.html), http://www.spaceweather.go.kr/models/ipsdenlil or at the Korean Space Weather Center (KSWC) see: http://www.spaceweather.go.kr/models/ipsdenlil The UCSD kinematic analyses of IPS data provide global measurements over a time cadence of about one day for both density and velocity, and slightly longer cadences for some magnetic field components. These currently provide boundaries from three different 3D-MHD models. The 3D-MHD simulation results using IPS boundaries as input compare fairly well with in-situ measurements. Real-time IPS boundary data for driving MHD model (ENLIL) are now available. We are well on our way in providing a system whereby the UCSD IPS tomography updates each 3D-MHD model iteratively for a refined-propagation analysis using these heliospheric models. References McKenna-Lawlor, S., Ip, W., Jackson, B., Odstrcil, D., Nieminen, P., Evans, H., Burch, J., Mandt, K., Goldstein, R., Richter, I., and Dryer, M., 2015, “Space Weather at comet 67P/Churyumov-Gerasimenko before its perihelion”, Earth, Moon, and Planets (submitted). Jackson, B.V., Hick, P.P., Buffington, A., Bisi, M.M., Clover, J.M., and Tokumaru, M., 2008, “Solar Mass Ejection Imager (SMEI) and Interplanetary Scintillation (IPS) 3D-Reconstructions of the Inner Heliosphere”, Adv. in Geosciences, 21, 339-366 Jackson, B.V., Odstrcil, D., Yu, H.-S., Hick, P.P., Buffington, A., Mejia-Ambriz, J.C., Kim, J., Hong, S., Kim, Y., Han, J., and Tokumaru, M., 2015, “The UCSD IPS Solar Wind Boundary and its use in the ENLIL 3D-MHD Prediction Model”, Space Weather, 13, 104, doi: 10.1002/2014SW001130. Kim, T.K., Pogorelov, N.V., Borovikov, S.N., Jackson, B.V., Yu, H.-S., Tokumaru, M., 2014, “MHD heliosphere with boundary conditions from a tomographic reconstruction using interplanetary scintillation data”, J. Geophys. Res., 119, 7981, doi:10.1002/2013JA019755. Odstrcil, D., et al. 2008. in ASP Conference Series Proceedings - Numerical Modeling of Space Plasma Flows, eds. N. V. Pogorelov, E. Audit, & G. P. Zank, “Numerical Simulations of Solar Wind Disturbances by Coupled Models”, 385, 167. Yu, H.-S., Jackson, B. V., Hick, P. P., Buffington, A., Odstrcil, D., Wu, C.-C., Davies, J. A., Bisi, M. M., and Tokumaru, M., 2015, “3D Reconstruction of Interplanetary Scintillation (IPS) Remote-Sensing Data: Global Solar Wind Boundaries for Driving 3D-MHD Models”, Solar Phys., doi: 10.1007/s11207-015-0685-0. Wu, C.-C., Liou, K., Jackson, B.V., Yu, H.S., Hutting, L., Lepping, R.P., Plunkett, S., Howard, R.A., and Socker, D., 2015, “The first super geomagnetic storm of solar cycle 24: The St. Patrick day (17 March 2015) event”, submitted to the SCOSTEP-WDS Workshop, NICT, Tokyo, Japan 28-30 September. Zhao, X.P., and Hoeksema, J.T., 1995, “Prediction of the interplanetary magnetic field strength,”, J. Geophys. Res., 100 (A1), 19-33. 6. Summary 3. Real-Time ENLIL and Rosetta Archival Analyses ENLIL driven by an IPS archival boundary provides a large, density enhancement at the Rosetta spacecraft situated 60° from the Sun- Earth line at 3.7 AU. The enhancement arriving at Rosetta was marked by an energetic solar wind plasma event at Rosetta on September 19 at 12 UT and is a combination of the 2014 September 9 &10 halo CMEs, the latter associated with an X1.6 flare at 17:30 UT and a geomagnetic storm at Earth ( McKenna-Lawlor et al., 2015 ). 4. 2011 September 24 Halo CMEs Using the UAH MS-FLUKSS ftp://cass185.ucsd.edu/data/IPS_Rosetta_Real_Time/ (For a Real-Time Rosetta IPS Kinematic Analysis see: ftp://cass185.ucsd.edu/data/IPS_Rosetta_Real_Time/ ) 5. 2015 March 15 Halo CMEs Using NRL’s H3D-MHD MS-FLUKSS driven by an archival IPS boundary analysis (see Kim et al., 2014) here provides a large, velocity enhancement from the 2011 September 24 Halo CMEs from a 0.1 AU boundary. Left) Time series showing radial velocity, from the IPS kinematic tomography and the IPS-driven MS-FLUKSS compared with OMNI data. Right) A radial cut at 1 AU from the MS-FLUKSS IPS- driven model at the time indicated by the blue arrow on the left plot. Pre-CME Solar Wind 1.0 AU Velocity CME Time of Radial Cut H3D-MHD driven by an archival IPS boundary analysis (Wu et al., 2015) provides a large enhancement from the 2015 March 15 Halo CMEs from a 40 Rs boundary. UCSD fields are input as Br, Bt, and Bn boundaries (RTN kinematic model B in-situ fits to the ACE spacecraft are shown). (see Jackson et al., 2015; Yu et al., 2015; Odstrcil et al., 2008)