Fig. 1: Decadal oscillation in Antarctic sea ice concentration.
From: Decadal oscillation provides skillful multiyear predictions of Antarctic sea ice
a The EOF2 pattern of Antarctic sea ice concentration (SIC). b The corresponding PC2 and the Antarctic decadal oscillation (AADO) index defined as the area-weighted average of SIC in the Ross-Amundsen Seas (180°–125°W, 60°S–75°S). c The local wavelet power spectrum using the Morlet wavelet, and the global wavelet/Fourier spectrums (right-hand panel) of the AADO index. The yellow contour indicates the 95% significance level using a red-noise background spectrum. The red dash line in the right-hand panel indicates the 95% confidence level for the global wavelet spectrum. d The 8-yr lowpass filtered series of the AADO index and the PC2 for the period 1981–2020. The gray shading indicates the positive phase of the AADO. The series has been detrended and normalized. Base map for Fig. 1a was generated using the NCAR Command Language (version 6.6.2).
