Figure 2: Fourier analysis (using Best Exact N composite algorithm) of the detrended Svalbard 1912–2010 MAAT series. The record is dominated by three periods of about 68.4, 25.7, and 16.8 yr length, all with amplitude greater than 0.8°C. In a statistical sense; however, the 2.45 yr peak is most important. The stippled lines indicate peak-based critical limit significance levels, while the grey tone indicates increasing amplitude. Only frequencies lower than 0.45 yr−1 are shown.