1. ST23-D2-PM2-P-013
The UCSD Kinematic Global Solar Wind Boundary for use in ENLIL 3D-MHD Forecasting
Bernard JACKSON1#+, Hsiu-Shan YU1, Paul HICK1, Andrew BUFFINGTON1, Nolan LUCKETT1,
Dusan ODSTRCIL2,
Sunhak HONG3, Jaehun KIM 3,
and Munetoshi TOKUMARU4
1Center for Astrophysics and Space Sciences, University of California, San Diego
9500 Gilman Drive #0424, La Jolla, CA , U.S.A.
2George Mason University, VA and NASA/GSFC, U.S.A.
3Korean Space Weather Center, Jeju, South Korea
4STELab, Nagoya University, Furo-cho, Chikusa-ku, Nagoya , Japan
#Corresponding author: +Presenter
(Sponsored by: AFOSR FA , NSF AGS , and the KSWC, Jeju, South Korea)
Abstract
The University of California, San Diego (UCSD) IPS time-dependent iterative kinematic modeling technique has been used and expanded-upon for over more than a decade to provide some of the most accurate forecasts of heliospheric solar-wind parameters now available. These parameters include global models of velocity, density, and through convection upward of magnetic fields from the solar surface, radial and tangential heliospheric fields. The precise time-dependent results can be extracted at any solar distance and are now being exploited as inner boundary values to drive the ENLIL 3D-MHD model in real-time. The advantage of this system is that it uses the superior physics of 3D-MHD modeling to provide an automatic forecast of CMEs and corotating structures several days in advance of the present at Earth without using coronagraph observations. Here, we explore the current differences between the IPS real-time kinematic analyses and those from the ENLIL 3D-MHD modeling using IPS-derived real-time boundaries.
1. Interplanetary Scintillation (IPS)
STELab IPS array systems
500 km
Interplanetary Scintillation (IPS) observations have long been used to remotely-sense small-scale ( km) heliospheric density variations along the line of sight in the solar wind. These density inhomogeneities disturb the signal from compact radio sources to produce an intensity variation when projected on the Earth’s surface. This pattern moves along the ground away from the Sun with the projected solar wind speed.
Solar-Terrestrial Environment Laboratory (STELab) radio array, Japan; the Fuji system is shown. USCD currently maintains a near-real-time website that analyzes and displays IPS data from the STELab. This modeling-analysis capability is also available at the CCMC (Community Coordinated Modeling Center) and the KSWC (Korean Space Weather Center) Jeju, South Korea.
This pattern, measured and correlated between different radio sites in Japan allows a determination of the solar wind speed. By cross-correlating the radio signal obtained at different IPS observing sites, we determine the solar wind speed. By measuring the scintillation strength of the IPS source, we can also determine the solar wind density.
STELab Website:
USCD Real-Time Website: http//:ips.ucsd.edu/ CCMC Website:
KSWC Website:
2. Real-Time UCSD Kinematic Model Forecast Webpages
Link to UCSD resources 
 Link to STELab website
Links to additional plots/services
UCSD velocity and density in-situ forecasts.
UCSD IPS forecast website front page.
See authors for the latest forecasts
(also see Jackson et al., 2010; 2013)
Links to additional plots/services
UCSD velocity and density ecliptic cut forecasts.
KSWC velocity and density ecliptic cuts and in-situ forecasts.

2. 4. Real-Time IPS-driven ENLIL Forecast Webpages
3. Global Solar Wind Boundary (ftp://cass185.ucsd.edu/data/IPSBD_Real_Time/)
Evaluating the 3D reconstruction at a given spherical radius provides a “global solar wind lower boundary” which can then be extrapolated outward by 3D-MHD models. Results of this extrapolation can be compared with in-situ measurements as a “ground truth” verification of this technique. These inner boundaries are extracted at Earth-centered Heliographic Coordinates at 0.1 AU for ENLIL 3D-MHD modeling (Odstrcil et al., 2008).
Density (a), velocity (b), and radial (c) and tangential (d) magnetic field inner boundaries for ENLIL extracted at 0.1AU from 3D time-dependent tomography using STELab IPS observations and NSO magnetograms.
4. Real-Time IPS-driven ENLIL Forecast Webpages
Links to additional models
Links to additional model plots
IPS-driven ENLIL 3D-MHD modeling forecasts. Velocity ecliptic cuts – in-situ time series.
IPS-driven ENLIL 3D-MHD modeling forecasts. Density ecliptic cuts – in-situ time series.
See authors for the latest forecasts
Detailed comparisons of the UCSD kinematic and 3D-MHD ENLIL results driven by time-dependent IPS boundaries compared with in-situ WIND results for two CMEs.
IPS
IPS
Correlation
Correlation
0.938
0.937
ENLIL
ENLIL
Correlation
Correlation
0.515
0.847
CME With a shock (red arrow) CME without (purple arrow) .
IPS
ENLIL
IPS
ENLIL
3-hour averaged in-situ observations.
5. Summary
The analysis of IPS data provides low-resolution global forecasts of solar wind density and velocity with a time cadence of one day for both density and velocity.
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.
References
Jackson, B. V., P.P. Hick, M.M. Bisi, J.M. Clover, A. and Buffington, 2010, “Inclusion of In-Situ Velocity Measurements into the UCSD Time-Dependent Tomography to Constrain
and Better-Forecast Remote-Sensing Observations”, Solar Phys., 265,
Jackson, B.V., Hick, P.P., Bisi, M.M., Clover, J.M., and Buffington, A., 2013, “Inclusion of Real-Time in-situ Measurements into the UCSD Time-Dependent Tomography and
Its Use as a Forecast Algorithm”, Solar Phys., 285, , doi: /s x.
Odstrcil, D., Pizzo, V.J., Arge, C.N., Bissi, M.M., Hick, P.P., Jackson, B.V., Ledvina, S.A., Luhmann, J.G., Linker, J.A., Mikic, Z., and Riley, P., 2008, “Numerical Simulations of
Solar Wind Disturbances by Coupled Models”, in ASP Conference Series Proceedings - Numerical Modeling of Space Plasma Flows, eds. N. V. Pogorelov, E. Audit,
and G. P. Zank , 385,