The Effects of Abrupt Wind Shears in the Solar Wind on the Earth's Magnetosphere

Monday, 15 December 2014: 9:00 AM
Joseph E Borovsky1, Athanasios Boudouridis1, Joachim Birn2 and Michael Denton3, (1)Space Science Institute, Boulder, CO, United States, (2)Space Science Institute, Los Alamos, NM, United States, (3)Space Science Institute Boulder, Boulder, CO, United States
The solar wind is filled sudden velocity shears. The shears take the form of vorticity layers co-located with current sheets. The velocity vector makes its change in a few seconds. For shear layers with vector velocity changes greater than 50 km/s, an average of 12 shear layers pass the Earth per day. Global magnetospheric MHD simulations with four different simulation codes have been performed at the Community Coordinated Modeling Center (CCMC) to examine the reaction of the Earth to the solar-wind velocity shears. All 4 simulation codes predict comet-like disconnections of the magnetotail, the magnetosheath, and the bow shock on the flanks as a shear layer passes the Earth. The simulation codes also predict sudden changes in the cross-polar-cap potential and ionospheric Joule dissipation as the shear layers pass the Earth. A data-analysis research effort is underway to look for signatures of the Earth’s reaction to abrupt wind shear events; preliminary results of that effort will be discussed.