ABSTRACT
Previous studies documented that the low solar activity since the beginning of the 21st century could directly drive the wintertime climate variability resembling the negative Arctic Oscillation (AO) responses. This study investigates the interdecadal variations of the solar-AO relationship and the related Arctic climate change. Results show that with more solar radiation mild (cold) winters are in the east (west) of Greenland after mid-1980s, in accordance with the positive AO-like pattern, which can be well explained by the coupling between stratosphere and troposphere. By contrast, the solar-related circulation anomalies are totally reversed before mid-1930s, corresponding to the opposite solar-AO connection.
Arctic Oscillation (AO) is an annular mode, extending from surface to the stratosphere, which represents the dominant interannual variability of the extratropical Northern Hemisphere with a seesaw of sea level pressure (SLP) anomalies between the high and middle latitudes (Thompson and Wallace, 1998). It has been widely documented that the AO has a substantial influence on global weather and climate (e.g. Gong et al., 2001; Park et al., 2011; Chen et al., 2016). For different areas in the entire Arctic region, the impacts of the AO on the surface air temperature/sea ice variations are different (Wang and Ikeda, 2000; Stroeve et al., 2011; Yang et al., 2016). A positive phase of AO favors increased (reduced) sea ice to the west (east) of Greenland through horizontal sea ice and temperature advection (Rigor et al. 2002; Zhang et al. 2003). Previous studies have also demonstrated that the interdecadal variability of the AO and its impacts on the large-scale circulation variations (Li et al., 2014; Chen et al., 2017). For instance, Wei and Su (2014) have reported that the Arctic SLP has experienced a decrease tendency since late-1980s and the rising temperature over Arctic region during the last decades of the 20th century has close relation with the AO variations (Overland and Wang, 2005a).
