Joanna D. Haigh

'Solar Variability and Climate Change'

Since ancient times, and the observation of variations in sunspot numbers, it has been speculated that changes in solar activity may influence the climate on Earth. The scientific literature provides a large number of examples of studies claiming correlations between different solar and meteorological parameters, although many of these do not stand rigorous statistical analysis and, until recently, the whole subject area was viewed with mistrust, if not derision, by the meteorological establishment. Since the availability of solar irradiance measurements from earth-orbiting satellites, however, it has been established that the solar “constant” is not. Furthermore, advances in computer power have enabled the development of sophisticated climate models that can incorporate many of the relevant processes.

This talk will outline the chequered history of solar-climate studies, review the evidence for an influence of the Sun on the lower atmosphere and discuss recent work using numerical circulation models that are helping to unravel some of the physical mechanisms involved.

Space and Atmospheric Physics, Imperial College London