Fig. 11From: Recovery of the 6-year signal in length of day and its long-term decreasing trendComparison of the relative amplitudes of the 6-year signals in t 1 and t 6 periods (a); the total variation trend of the amplitudes in six periods in time domain and the green cycles refer to the relative amplitudes of the 6-year signal in various periods (b); the time window this paper uses is hamming windowBack to article page