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How does the Sun create space weather near Earth?

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Space weather Earth's full North Polar auroral oval, in an image taken in ultraviolet light by the U.S. Polar spacecraft over northern Canada, April 6, 1996. In the colour-coded image, which simultaneously shows dayside and nightside auroral activity, the most intense levels of activity are red, and the lowest levels are blue. Polar, launched in February 1996, was designed to further scientists' understanding of how plasma energy contained in the solar wind interacts with Earth's magnetosphere.

The Sun creates space weather near Earth primarily through the solar wind, a continuous stream of charged particles and magnetic fields flowing from the solar corona.12

When this solar wind encounters Earth’s magnetic field, it forms a protective cavity known as the magnetosphere. Space weather phenomena arise from the dynamic interaction between the solar wind and this magnetosphere, driven by several key mechanisms:13

Magnetic Reconnection: This process allows solar plasma to enter the magnetosphere by linking the Sun’s magnetic field with Earth’s. It can explosively release energy, leading to geomagnetic storms and auroral displays.13
Solar Activity: Events such as solar flares and coronal mass ejections increase the flux of energetic particles, which can disturb the ionosphere and interfere with satellite communication and navigation systems.145
Ionospheric Perturbations: Solar radiation and particle impacts alter ionospheric density, which can absorb or refract radio waves, impacting global technology and power grids.465

These effects vary significantly over the 11-year solar cycle, with the most intense space weather occurring during the solar maximum.1