It constantly releases charged subatomic particles. These stream through the Solar System as the solar wind, carrying with them an imprint of the Sun's magnetic field. It is these 'field rays' that interact with, and partially shield the Earth from, cosmic rays. The strength of the solar wind depends on the level of solar activity, and so varies with the sunspot cycle. When the solar wind blows less forcefully, more cosmic rays streak through our atmosphere.
Clouds have a strong yet subtle effect on climate.
Clouds that form low in the sky are relatively warm and made up of tiny water droplets. These tend to cool the planet by reflecting sunlight back into space. High clouds are colder, consisting mostly of ice particles, and they can have the opposite effect of warming the Earth by trapping heat. Clouds higher than these appear insensitive to changes in the flux. They argue that the imprint of the solar magnetic field in the solar wind has increased over the past century.