FöRFATTARE
Westerberg, Lars-Göran

INSTITUTION
Tillämpad fysik, maskin- och materialteknik / Strömningslära

SAMMANFATTNING
The solar wind interaction with the terrestrial magnetosphere is a source for many spectacular phenomena on or close the Earth's surface. A key question during the last fifty years have been how the solar wind plasma can enter the terrestrial magnetic shield represented by the magnetosphere and its outermost layer called the magnetopause. This have been the seed for many controversies among researchers throughout the years. Today we know that there are several possibilities for the solar wind to break through the magnetic boundary of the Earth. The main plasma transport mechanism at the magnetopause is called magnetic reconnection, where the magnetic energy stored in the solar wind is converted to kinetic energy through a localized break-down of the ideal frozen-in condition of the magnetic field within the plasma. Since its introduction to the space-physical community in the late 1950's, reconnection research have had its primary focus on understanding the onset mechanisms inside the diffusion region where the solar wind magnetic field is reconnected with the magnetospheric magnetic field. In this thesis work we put the context well out of the diffusion region and focuses on the implications of magnetic reconnection onto the surrounding solar wind plasma, rather than on the main mechanisms which initiates the process. We present solutions for the structure of the plasma flow through the magnetopause surface during conditions of ongoing reconnection. This is done through viscous-resistive reconnection models together with models where finite gyro-radius effects are considered. In order to validate the viscous-resistive model we also couple the analytical solutions with \textit{in situ} measurements made by the Cluster spacecraft fleet. This results in an entirely new way of determining the magnetopause transition layer thickness and the location of the reconnection site from spacecraft data.

ISSN 1402-1544 / ISRN LTU-DT--07/33--SE / NR 2007:33