Sea surface temperatures in the Bay of Bengal through the Pliocene-Pleistocene climate transition

Abstract

The Pliocene-Pleistocene climate transition is characterized with a global cooling trend and increased glacial-interglacials. During this climate transition sea surface temperatures (SST) in the Indo-Pacific Warm Pool (IPWP) remained stable, while SST in the eastern equatorial Pacific cooled 1-2°C. There are few SST records in the Indian Ocean regions that link the IPWP to the areas with strong monsoon variations. We reconstructed paleoclimate conditions through the Pliocene-Pleistocene climate transition in the Bay of Bengal at IODP Site 1451A (8°N, 88°E in 3607 m water depth). We used the Mg/Ca of T. sacculifer to establish a SST record that maintained stability with a trend of ~0.6°C that is statistically insignificant. We refined the Site U1451A age model by comparing the Site U1451A U. peregrina benthic δ18O record to the global benthic δ18O record (the LR04 stack). The refined age model defined gives the time interval of ~2.1-3 Ma with an uncertainty of ±20 kyr.