Thermal coupling of the Indo-Pacific warm pool and Southern Ocean over the past 30,000 years

The role of the tropical Pacific Ocean and its linkages to the southern hemisphere during the last deglacial warming remain highly controversial. This study explores the evolution of Pacific horizontal and vertical thermal gradients over the past 30 kyr using 340 sea surface and 7 subsurface temperature records, plus a new ocean heat content record. La Niña-like conditions dominated during deglaciation due to more intense warming in the western Pacific warm pool. Subsurface temperature and ocean heat content in the warm pool rose earlier than sea surface temperature, in phase with South Pacific subsurface temperature and orbital precession. This suggests heat exchange between the tropical upper water column and the extratropical Southern Ocean facilitated faster warming in the western Pacific, highlighting the thermal coupling between the warm pool and Southern Ocean's key role in global warming.

Shuai Zhang, Zhoufei Yu, Yue Wang, Xun Gong, Ann Holbourn, Fengming Chang, Heng Liu, Xuhua Cheng, Tiegang Li