Study of ultra low frequency waves in the magnetosheath of Venus

Abstract

The planet Venus, despite similarities in physical aspects with Earth, has some significant differences, among these differences is the absence of an intrinsic magnetic field on Venus. Even with the absence of the magnetic field, there is a formation of a magnetosphere by the interaction of the solar wind and the Venusian ionosphere, called the induced magnetosphere. Due to the flow of the supersonic or supermagnetosonic solar wind being deflected by the magnetized obstacle of the ionized planetary atmosphere, a shock front occurs in the flow outside the planet. This shock front prevents the solar wind from directly penetrating the planet, being deflected, compressed and disturbed around Venus, thus forming the induced magnetosphere regions. Due to this shock, oscillations of ions and electrons are formed and when energized enough they are reflected along the boundary being transported in abundance in the magnetosheath region, giving rise to ultra low frequency waves (ULF). The propagation of these waves is of paramount importance and should be considered for studies, as such waves play an important role in the transfer of energy and momentum to the internal magnetosphere. Therefore, for a better understanding of the Venusian magnetosphere it is necessary to identify and understand the influences of these waves in the Venusian plasma environments. The main objective of this project is to study and identify the main frequencies of ULF waves in the magnetosheath region of Venus from data on density, temperature, magnetic field, pressure and plasma velocity parameters obtained from instruments that were aboard the probe. Venus Express (VEX). To determine these frequencies, the Wavelet Transform technique will be used in time series of electron density and magnetic field for VEX crossing intervals by the planet's magnetosheath. Wavelet analyzes will be applied for one year in the solar minimum period (2007) and one year during the solar maximum period (2013). (AU)