[M-IS03] Evolution and variability of the Asian monsoon in Cenozoic global climate changes

[MIS03-P06] Amplitude modulation of sea surface temperature variability in the Bay of Bengal by 400-kyr eccentricity cycle

*Masanobu Yamamoto¹, Yuko Tsuchiya¹, Steven Clemens² (1.Faculty of Environmental Earth Science, Hokkaido University, 2.Department of Earth, Planetary and Environmental Sciences, Brown University)

Keywords:Bay of Bengal, Sea surface temperature, Mid-Pleistocene Transition

We generated a 1.7 kyr-resolution TEX₈₆-based sea surface temperature (SST) record from the International Ocean Discovery Program Site U1446 in the Bay of Bengal during the last 1.46 Myr. The SST varied synchronously with LR04 benthic foraminifera δ¹⁸O and deep water δ¹³C. The cyclicity changed from 41-kyr to 100-kyr around 900 ka. The amplitude of SST variation responded to the 400-kyr cycles of eccentricity. Higher amplitude corresponded to low eccentricity. This suggests that eccentricity forced climate variability independently of the shift of cyclicity of glacial cycles across the Mid-Pleistocene Transition.