There is growing evidence that variability associated with the 11-year solar cycle has an impact at the Earth's surface and influences its weather and climate. Although the direct global response to the Sun's variability is extremely small, a number of different mechanisms have been suggested that could amplify the signal, resulting in regional signals that are much larger than expected. A modulation of the ultra-violet part
of the solar spectrum, influences ozone production in the stratosphere, alter stratospheric circulation with subsequent changes in tropospheric circulation and climate. Solar absorption by the ocean and atmosphere-ocean coupling could amplify regional responses. However, some of the observed solar signatures could be a mere artifact of poor statistics given the shortness of observations. Hence, we are looking for
evidence of solar cycle influences on climate in carefully designed experiments with general circulation models and paleo-climate datasets.