8-12 juin, 2014


Solar Contributions to Climate Change

Donald C. Morton (National Research Council, Herzberg Program)

Our sun has been acting strangely lately. The peak sunspot count in cycles 19 (~1958), 21 (~1980) and 22 (~1990) were the highest since telescope observations began in 1610 and cycles 20 and 23 were only a little lower. However, the present cycle 24 has had only half the highest count so far and the minimum beginning about 2003 was unusually broad. Consequently there has been speculation that the sun could be heading for another Dalton Minimum or even a Maunder Minimum when spots were scarce and glaciers worldwide were advancing. Thus it is noteworthy that the rise in global temperature during the last quarter of the 20th century has been followed by a slight decreasing trend, while the concentration of CO2 has continued to rise in our atmosphere. This paper will explore possible ways changing solar activity can influence the earth's climate such as variations in the total irradiance or the UV component and the inverse correlation with the intensity of galactic cosmic rays.
(doit être confirmé par le SOC)