HR: 0800h
AN: SH11A-0260    [Abstracts]
TI: Comparison of Stream Interactions between Observation and ENLIL Model
AU: * JIAN, L
EM: jlan@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 595 Charles E Young Dr East, 6862 Slichter, Los Angeles, CA 90095 United States
AU: Russell, C T
EM: ctrussel@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 595 Charles E Young Dr East, 6862 Slichter, Los Angeles, CA 90095 United States
AU: Luhmann, J G
EM: jgluhman@ssl.berkeley.edu
AF: Space Science Laboratory, University of California, Berkeley, SSL University of California Berkeley, 7 Gauss Way, Berkeley, CA 94720 United States
AU: Odstrcil, D
EM: Dusan.Odstrcil@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado; and Space Environment Center, University of Colorado/CIRES, 325 Broadway, Boulder, CO 80805 United States
AB: When fast stream overtakes slow stream in the solar wind, a pressure ridge forms between them to accelerate the slow stream and decelerate the fast stream. The height of this pressure ridge is a measure of the strength of the interaction. We have examined the pressure ridges at 1 AU in the ecliptic plane at stream interactions over a full solar cycle. We find that the solar wind stream structure is surprisingly constant over the solar cycle with a minimum annual average pressure of about 133 pPa and a maximum of about 231 pPa. To understand the radial evolution of these structures, we compare our results with the ENLIL 3D MHD model of the heliosphere installed at the CCMC. This model solves for plasma mass, momentum, energy density, and magnetic field, using a Total-Variation-Diminishing Lax-Friedrichs (TVDLF) algorithm. We find that the current version of the model underestimates the pressure maxima observed in stream interaction ridges. However, some general trends in the parameters are reproduced, suggesting adjustments in the grid resolution or assumed solar wind parameters may improve the comparisons.
DE: 7509 Corona
DE: 7524 Magnetic fields
DE: 7536 Solar activity cycle (2162)
DE: 7599 General or miscellaneous
DE: 7959 Models
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005