Atmosphere–ocean interactions in the Greenland Sea during solar cycles 23–24, 2002–2011

Abstract

Relationships between solar activity and climate in the North Atlantic region have long been reported and, more recently, mechanisms have been proposed to explain these. Normally such relationships are tested over decadal time scales. Here, daily sea surface temperature fields bridging the period of exceptionally low solar activity between solar cycles 23 and 24 have been analysed. The day-to-day variability of the fields has been measured and the fields have been classified, using cluster analysis. The main water masses are clearly expressed, together with detail of their interactions. Three features relate to the level of solar activity. First, there is a statistically significant difference in the day-to-day variability of the sea surface temperature field between the period of lowest solar activity and the remaining periods. Second, during the transition from summer to winter, there are systematic, inter-annual changes in the day-to-day variability of the sea surface temperature field. Third, the forms of the late summer temperature fields exhibit symmetry about the years of lowest solar activity. These features are attributable to variability in the passage of weather systems. The influence on North Atlantic surface climate of variations in the solar ultraviolet band acting through the stratosphere has been reported in a number of studies. This provides a credible mechanism for solar activity influencing sea surface temperatures in the Greenland Sea.