Solar wind and geomagnetic activity

Nowadays, there are a lot of doubts about solar wind generation and most of what is known comes from observations. This is because its generation is too complex and the non-existence of observations in the regions where the wind is accelerated. However, near the Earth its features are well known and always measured. Solar wind interaction with the Earth magnetosphere leads to the formation of several magnetospheric regions. If the conditions are favorable such interaction leads also to geomagnetic activity. Studying geomagnetic activity variations caused by solar wind conditions is a main topic in space physics. For practical and technological aplications such variations can, for instance, damage ground and onbord satellites sistems because of the enhancement in atmospheric currents and levels of radiation, making this kind of research so important. This paper presents a brief revision about some of the main effects of solar wind and Earth's magnetosphere interaction.