The impact of solar activities on the boreal winter climate and its decadal variation

A lot of analysis revealed the relation between the variation of solar activity and climate over pole and high latitudes. Among them, Artic oscillation (AO) demonstrates a closely relationship with solar activity. Based on the F10.7cm solar radiant flux and NCEP reanalysis data sets from 1952 to 2011, we studied the impact of the variation of solar activity on the boreal winter climate over north hemisphere. Results show that solar activity closely related with the winter atmospheric circulation over East Asia. However, the relationship exhibits obviously differences between strong and weak solar activity periods. It suggests solar activity present an asymmetric influence on winter climate over East Asia. Further investigation indicates that the linkage between solar activity and East Asia winter climate is robust during active solar period but the connection is fairly weak during inactive phases. The more detail analysis reveals that the spacial characteristic of the atmospheric response to the solar variation is obviously different before and after later years 1970s. AO and F10.7cm flux appears a negative relation before 1978 but distinct positive relationship during the later years. During the period from 1952 to 1978, the variation of the solar activity is related to the sea surface temperature anomaly over Pacific and atmospheric zonal wind over tropical and low latitudes. On the other hand, it has a more closely relationship with temperature anomaly over Europe and Asian continent and the atmospheric circulation over mid-high latitudes during the time from 1979 to 2011. It is possibly caused by the climate condition transition in later 1970s and the solar radiant decadal variation influence on stratosphere and troposphere interaction.