Records of sea surface temperature (SST) over the last 1.5 million years from 16 marine sediment cores, complemented by an Antarctic ice core surface temperature record over the last 800 thousand years, are compiled for the purpose of analysing interglacial and glacial intensities. Records had to meet criteria of resolution, completeness and length, with some leniency to improve spatial coverage. Glacial maxima show an overall trend towards cooler SSTs over the past 1.5 million years, with particularly strong glacials since the Mid-Brunhes Shift (MBS; 450 thousand years ago). Interglacial peak SSTs do not show an overall cooling trend, but exhibit a tendency towards cooler conditions from 1.5 to 0.5 million years ago. Marine Isotope Stage (MIS) 5e emerges as the warmest interglacial of the last 1.5 Myr across most latitudes. Early interglacials MIS 49, 47, 43, 37 are also particularly warm along with MIS 9e. Intensity and termination amplitude are generally more variable at higher latitudes. While there is spatial variability, the data show an overall coherence, with strength or weakness in particular interglacials and glacials generally expressed across latitudes. A relationship between strong glacials and strong subsequent interglacials appears to hold since the MBS. It is coupled with greater termination increases in CO 2 concentration, pointing to a link between ice-sheet size, meltwater forcing and attendant changes in ocean circulation, ocean heat content and the carbon cycle. • We compile sea surface temperature (SST) records covering the last 1.5 Myr. • Glacial maxima show an overall trend towards cooler SSTs over the past 1.5 Myr. • MIS 5e emerges as the warmest interglacial of the last 1.5 Myr across most latitudes. • Strong interglacials follow strong glacials since 450 ka, pointing to: • A link between of ice-sheet size, deglaciation, and release of ocean-stored heat and CO 2 .
Watson et al. (Tue,) studied this question.