The Bow Shock Normal and the IMF Angle of Incidence: Preliminary Description

The bow shock is a complex structure wich is formed by the interaction between the geomagnetic field and the incoming plasma from the Sun in the form of solar wind and ICME's. The effects of this interaction are clearly visible in the form of geomagnetic storms, substorms and auroras in high latitude regions. Our current understanding of this interaction is not completely clear but is nowadays is well know that the direction of the IMF plays a central role in the development of most of the associated phenomena involved in the near earth space weather research. In this work we present a preliminary analytical approach to the study of the inteaction between the normal direction, relative to the bow shock, and the IMF angle of incidence in the so called "Quasi-Perpendicular Shocks" (QPS), where the relative angle of incidence is greater than 45 degrees, using the standard shock wave description in the hidrodynamic regime and the MHD approximation. This is the first step for a more comprenhesive study involving spacecraft data, providing the required theoretical background in order to achieve a more solid modeling of this phenomenon.