The Earth's magnetic field deflects about 1.5 million tons of material ejected from the Sun every second. If it were not there, the atmosphere would suffer direct and continuous erosion.
The connection between the magnetosphere and the solar wind is the heart of what is known as space weather. The magnetic field is twice as intense at the poles as at the equator. It is also inclined 11.5 degrees with respect to the planet's axis of rotation, which is what defines the geographical north and south poles.