Supermagnetosonic subsolar magnetosheath jets and their effects: from the solar wind to the ionospheric convection

Abstract

It has recently been proposed that ripples inherent to the bow shock during radial interplanetary magnetic field (IMF) may produce local high speed flows in the magnetosheath. These jets can have a dynamic pressure much larger than the dynamic pressure of the solar wind. On 17 March 2007, several jets of this type were observed by the Cluster spacecraft. We study in detail these jets and their effects on the magnetopause, the magnetosphere, and the ionospheric convection. We find that (1) the jets could have a scale size of up to a few RE but less than similar to 6 R-E transverse to the XGSE axis; (2) the jets caused significant local magnetopause perturbations due to their high dynamic pressure; (3) during the period when the jets were observed, irregular pulsations at the geostationary orbit and localised flow enhancements in the ionosphere were detected. We suggest that these inner magnetospheric phenomena were caused by the magnetosheath jets.

Description

Keywords

Interplanetary physics, Planetary bow shocks, Magnetospheric physics, Magnetosheath, Solar wind-magnetosphere interactions, Flux-transfer events, Parallel bow shock, Upstream pressure variations, High-latitude convection, Quasi-parallel, Magnetic fluids, Earths, Magnetosheath, Radar observations, Ion reflection, Cluster, Astronomy & astrophysics, Geosciences, multidisciplinary, Meteorology, Atmospheric sciences

Citation

Hietala, H., Partamies, N., Laitinen, T. V., Clausen, L. B. N., Facskó, G., Vaivads, A., Koskinen, H. E. J., Dandouras, I., Rème, H., and Lucek, E. A.: Supermagnetosonic subsolar magnetosheath jets and their effects: from the solar wind to the ionospheric convection, Ann. Geophys., 30, 33-48, doi:10.5194/angeo-30-33-2012, 2012.