Solar Wind Variations Related to Fluctuations of the North Atlantic Oscillation

A study on a possible solar wind interaction with the North AtlanticOscillation (NAO) is performed. Results are presented suggesting arelationship between the NAO index and the electric field strength E ofthe solar wind. A possible scenario for the suggested interaction isthat an electromagnetic disturbance is generated by the solar wind inthe global electric circuit of the ionosphere. This disturbance is thendynamically propagating downward through the atmosphere and subsequentlyinfluencing the large-scale pressure system in the North Atlanticregion. A relationship is also evident on longer time-scales when usingthe group sunspot number as a proxy for the solar wind. (Art. No. 1718

Solar mean magnetic field variability: A wavelet approach to Wilcox Solar Observatory and SOHO/Michelson Doppler Imager observations

Solar mean magnetic field (SMMF) measurements from the Wilcox Solar Observatory and with the SOHO/MDI instrument are described and analyzed. Even though two completely different methods of observation are used, the two data sets obtained show a strong similarity. Using continuous wavelet transforms, SMMF variability is found at a number of temporal scales. Detected SMMF signals with a 1–2 year period are considered to be linked to variations in the internal rotation of the Sun. Intermediate SMMF oscillations with a period of 80–200 days are probably connected to the evolution of large active regions. We also find evidence for 90 min variations with coronal mass ejections as a suggested origin

Brief communication: Impact of common ice mask in surface mass balance estimates over the Antarctic ice sheet

Regional climate models compute ice sheet surface mass balance (SMB) over a mask that defines the area covered by glacier ice, but ice masks have not been harmonised between models. Intercomparison studies of modelled SMB therefore use a common ice mask. The SMB in areas outside the common ice mask, which are typically coastal and high-precipitation regions, is discarded. Ice mask differences change integrated SMB by between 40.5 and 140.6 Gt yr(-1) (1.8 % to 6.0 % of ensemble mean SMB), equivalent to the entire Antarctic mass imbalance. We conclude there is a pressing need for a common ice mask protocol