Solar-Terrestrial Influence

Summary

The sun extends far away: the earth is in the sun.

It is therefore no surprise that the sun has a direct influence on the earth. The sun’s influence on the earth and the planet exerts itself through gravitational, particles from the solar wind, the magnetic field and radiation. Nearly all the related effects have been studied or discovered mainly because of advances in space research. 25 years of space research have indeed revealed the existence of the solar wind and the structure of the interplanetary medium between the earth and the sun as well as the structure of the solar magnetic field, and the detailed shape and evolution of the earth magnetosphere.

The interaction between the earth’s amosphere and solar radiation is strongly dependent upon the portion of the spectrum that is considered. The upper layers are directly influenced by the ultraviolet whose intensity is strongly dependent upon the degree of activity of the sun.

How far down this influence extend in proximity to the ground and to what extent is the climate of the earth influenced by the variation in the total radiative output of the sun are questions of major interest to humanity. Not only do they relate to our daily activity (the weather, the climate) but also to the evolution of life.

These various problems are discussed. historical aspects as well as the most recent results provided by space research are described.