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A Characterization of Pleistocene Climate as Revealed by Empirical Mode Decomposition

Alex M. Gerber and Matthew J. Rodrigues


A consensus as to the characterization of the Pleistocene's climate with respect to Milankovich theory (the forcing of climate by orbital dynamics) has remained elusive. In part, this is due of the shortcomings of classical techniques such as Fourier analysis in the study of nonlinear, nonstationary data. Recently, a new ocean sediment record, containing a proxy for global temperature, has been constructed with an age-model devoid of orbital assumptions -- thereby allowing for the testing of the validity of Milankovich theory. We analyze this record using a relatively new data-adaptive technique known as empirical mode decomposition (EMD), which is well suited for the study of nonlinear and nonstationary time data. Our EMD analysis clearly isolates the various components of this complicated time series and provides new insight into the behavior of the climate during the Pleistocene.