Mirror modes observed with Cluster in the Earth's magnetosheath : statistical study and IMF/solar wind dependence

Vincent Génot (1) , E. Budnik (1) , C. Jacquey (1) , I. Dandouras (1) , E. Lucek (2)

1 CESR - Centre d'étude spatiale des rayonnements
2 Blackett Laboratory

We present a statistical analysis of 5 years of Cluster mission data in the magnetosheath. Our primary focus is to exhibit the spatial distribution of mirror mode events. The automatized detection is based on Minimum Variance Analysis and the amplitude of events. The results are displayed in the GIPM reference frame to enable comparison with a previous similar study using ISEE- 1 data. These results compare favorably with each other and with studies focusing on Jupiter's and Saturn's magnetosheaths. We further analyze the dependence of the mirror events with solar wind parameters and Interplanetary Magnetic Field (IMF) orientation. We notably reveal that the occurrence of mirror modes is relatively more probable during periods of time when the IMF is not following the common Parker spiral orientation.

Mots clés: Magnetosheath turbulence; Mirror mode; Statistical data analysis; Cluster observations

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]

Vincent Génot, E. Budnik, C. Jacquey, I. Dandouras, E. Lucek. Mirror modes observed with Cluster in the Earth's magnetosheath : statistical study and IMF/solar wind dependence. ADVANCES IN GEOSCIENCES, World Scientific Publishing Co., pp.1, 2009. ⟨hal-00378804⟩