Part of the show Forecasting Weather and Climate
Paul in Norwich and Richard in Cambridge asked:
Are there any immediate effects of sun spots on the weather, such as when solar bursts occur? What about long term cycles like the eleven year sun spot cycle. Do they affect jet streams and so on?
I think you do get a slight effect on it because you get more energy input when the sun's particularly active but it's a fairly routine and regularly forecast cycle. So we wouldn't use it hugely to impact on our daily weather forecast. If you're talking about longer term weather and you're starting to talk about climate then it's certainly the case that if you look at, for example, the last century then periods of strong solar activity were associated with periods of warmer temperatures. However, that influence in the latter part of the century was greatly outweighed by the effect of increasing levels of carbon dioxide. If you calculate the amount of energy that comes from the sun you get a little bit extra when the sun spots are very active. That does tend to make the weather a little bit more active but as for its actual impact on me as a weather forecaster, it's relatively small.