Influence of the Magnetosheath Waves on the Dayside Reconnection

We investigate the influence of the magnetosheath waves on the temporal and spatial variations of the dayside magnetopause reconnection using the global hybrid-Vlasov simulation Vlasiator (http://vlasiator.fmi.fi) developed at the Finnish Meteorological Institute. In simulations with steady solar wind conditions we observe waves with the characteristics of mirror modes form behind the terrestrial bow shock and advect to the magnetopause. These compressional waves have anticorrelated magnetic field and density causing large beta variations and thus could cause variation in the properties of reconnection. At the magnetopause boundary there is strong evidence for magnetic reconnection including the formation of two-dimensional equivalents of flux transfer events (FTE). There are large variations in the temporal and spatial properties of the FTEs indicating a possible connection to the variations in the magnetosheath inflow region. Finally, we compare our results with THEMIS observation from the magnetopause crossings.