Search for plasma and magnetic field cavities in magnetosheath

In the solar wind, foreshock cavities create depressed magnetic field and density regions associated with high energetic particles due bow shock related processes. In this study, we searched for the presence of foreshock type transient events in the magnetosheath using Interball-1 spacecraft data. In our search of four years of magnetosheath magnetic field, density, temperature, velocity and proton flux data, we have not found signatures of these cavities. The relation between magnetosheath parameters and energetic particles is not clearly revelaed in Interball-1 data. While these events are very clear and commonly found in the solar wind, why they are not observed in the magnetosheath emposes an interesting and challenging question on the evolution of these solar wind structures and their relation to the ;magnetosheath dynamics. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.