Migrations of the Indo-Pacific Warm Pool through the past eight glacial cycles

High-resolution and long-term paleorecords from the central Indo-Pacific Warm Pool (IPWP) will help us understand tropical climates. Here, we present a high-resolution record (alkenone SST, alkenone mass accumulation rate and opal content %) of piston core MD01-2380 retrieved from the Banda Sea, eastern Indonesia, to track changes in sea surface temperature, paleo-productivity, and upwelling activities in the Banda Sea. Combined with published paleo-time series from the same region, we have reconstructed the zonal (east-west) and meridional (equator to mid-latitudes) gradients in sea surface temperature of the warm pool over the past eight glacial cycles. These gradients control zonal and meridional atmospheric circulations and reflect the dynamics of expansion and contraction of the warm pool. The pronounced zonal gradients in sea surface temperature show different patterns before and after the Middle Brunhes Event (MBE), as well as enhanced upwelling in the Banda Sea after the MBE. We suggest that shoaling of the western equatorial Pacific thermocline has induced more CO2 release into the atmosphere from the deep sea.