From Fourier analysis we can determine that the Pacific Decadal Oscillation, which affects temperature, has a period of about 24 years. Sunspots have an oscillation period of about 12 years and also affect temperature. (I have adjusted the numbers slightly to make one period exactly twice the other period.) Carefully sketch a graph of the resulting temperature oscillations (so graph temperature vs. time) for each of these temperature oscillations, and then sketch a graph of how these temperature oscillations will combine.