When the wind's magnetic field is opposite from Earth's, an connection occurs. Imbalances are formed between the sunlit and dark side. After magnetic reconnection happens, charged particles rush into the magnetosphere causing magnetic storms and auroras. The solar wind, which has its own magnetic field, pushes against the magnetosphere. It compresses the day side and stretches the night side, like a wind sock.
Auroras are usually a result of magnetic reconnection.
Think of the sun as a big jet engine in the sky, and the solar wind is the exhaust of that jet engine. When solar wind arrives at Earth, it has the capability of disrupting the size and shape of the earth's magnetic field and can cause tears in our magnetic cocoon, allowing solar particles into our atmosphere. The sun has a magnetic field, but it is far more complex than Earth's. The year 2000 is the year of the solar maximum. This is NOT a finished production and contains no narration.