Time dependence of the regional surface response to a Grand Solar Minimum in a climate model

We investigate the possible impacts of a Grand Solar Minimum over the 21st century on surface climate in the HadGEM2-CC model. The sensitivity to the assumed parameterization of solar UV variability is examined.

The high latitude surface response is found to be time dependent and sensitive to the magnitude of the ΔUV perturbation. For a 6% decrease in solar UV, a strong negative NAO response occurs in the mid 20th century but decreases by 2100 while greenhouse gas concentrations continue to increase. In contrast, for a 0.8% decrease in solar UV the high latitude response increases in magnitude over the 21st century but less closely resembles the NAO. Changes in tropospheric blocking frequency in response to the solar minimum are also analysed. As expected, the impacts on global mean surface temperature are small in both sets of experiments.