March 9, 2014

expert reaction to new study on solar forcing

Research in Nature Geoscience looked at seafloor sediments as a measure of  how changes in the sun’s energy output may have contributed to natural climate change in Europe over the last 1000 years.

Prof Joanna Haigh, Professor of Atmospheric Physics at Imperial College London, said:

“This paper presents 1000-year long records of solar irradiance, ocean temperature and salinity derived from isotope records in ocean sediment cores extracted from two locations in the North Atlantic.   

“It shows a positive correlation between solar activity and ocean temperature on centennial timescales, with notable cooler periods, at the core locations, coinciding with minima in sunspot activity, and thus provides a significant new contribution to understanding the links between the Sun and the climate on regional scales.  Interpretation of the observations, using a computer model of the atmosphere and ocean, confirms previous studies which suggest that solar-induced changes in the position of the jet stream and storm tracks result in cooler temperatures over north-western Europe when the Sun is less active.

“This effect may help to explain some aspects of local climate variations but, as stressed by the paper’s authors, it does not suggest that the Sun is responsible for global warming over the past 150 years.”

‘Solar forcing of North Atlantic surface temperature and salinity over the past millennium’ by Paola Moffa-Sánchez et al. published in Nature Geoscience Sunday 9 March.