EXPI, NOAA/SEC, UAH and GI/UAF

1. NASA Grant NAG5-12527 and NASA Interagency Transfer W-10,118Period of Performance: Sep. 1, 2002 - Aug. 31, 2005 We predicted disturbances in the ecliptic plane IMF out to 10 AU during the October-November 2003 “Halloween events”. Red lines indicate “away sectors” (field lines directed outward from the Sun) and blue lines show “toward sectors” (inward-directed field lines). We also used the outputs of the solar wind model to predict the Ap geomagnetic storm index, a key space weather indicator. We compared the observed AP (blue) with our prediction (red) and evaluated our forecast skill. Green is the difference. EXPI, NOAA/SEC, UAH and GI/UAF

2. Project Goal: We want to understand the relationship between the observed features on the Sun and the behavior of the solar wind, the IMF, and the terrestrial response over the 11-year solar activity cycle. Significance: The solar wind is a key link in the chain of space weather extending from the Sun to the Earth and beyond. Understanding it is critical to predicting geomagnetic storms and space radiation hazards. What we are doing: We are developing a Hybrid Kinematic/3D MHD solar wind model (H3DM) and using it to study the causes of IMF Bz over the solar activity cycle. Key features of the system are: it couples two mature solar wind models - HAF (Hakamada-Akasofu-Fry) and IGMV (Interplanetary Global Model, Vectorized); it is driven by solar observations and provides time-dependent solar wind conditions at the locations of spacecraft in interplanetary space. What we’ve done so far: Using only solar observations as inputs, we simulated the propagation of interplanetary shocks from the Sun to beyond 10 AU during the Halloween event period (Oct.–Nov., 2003). We compared HAF model simulation results with observations from spacecraft including Advanced Composition Explorer (ACE), Mars Global Surveyor (MGS), Ulysses, Cassini, Voyager 1 and 2. The realistic simulations allowed us to interpret spacecraft observations at Earth and Mars following the Oct. 28, 2003, X17 solar event. We evaluated IGMV-based predictions of the Ap geomagnetic index for the years 1994, 1995 and 2002. Scientific impact during the first two years of the project: We published 22 papers in scientific journals (or are in press), 25 were submitted or in preparation, and we made 40 presentations at organized national and international scientific meetings.