Polar Climate Connections of the Last Glacial Period

Ever since the cross-core chronology became available, the connection between the Earth’s polar regions - or the lack of such [Wunsch, 2003; 2006] - has been an on-going debate in the paleoclimate community. While the inverse relationship inferred from the bipolar seesaw model [Crowley, 1992] could not account for the difference in signal shape of the polar records, integration/differentiation (I/D) has been proposed as the linkage between them [Schmittner et al., 2003; Huybers, 2004; Roe and Steig, 2004; Schmittner et al., 2004]. Stoker and Johnsen [2003] have proposed a revised (thermal) bipolar seesaw model (TBS), demonstrating that the climate record from Antarctic is that of the Greenland convolved with an exponential decaying function, which represents the heat reservoir of the Southern Ocean. More recently, Rial [2012] has proposed phase synchronization (PS) as the polar climate connection from which polar climate records can be treated approximately as a Hilbert transform pair. All three models (I/D, TBS, and PS) have been used to reconstruct past climate of the north from the longer climate record of the south [Siddall et al., 2006; Barker et al., 2011; Oh et al., 2014]. However, no comparison has been made to test and analyze these models against one another for their performance and stabilities. Here we investigated the aforementioned models with polar climate data on the recent AICC2012 chronology to derive the similarities and differences among them in both time and frequency domains. Most importantly we discussed how such differences translate to the discrepancies in reconstructions of the northern climate and possible physical mechanism(s) of connection each model limits and allows.