Geophysical Research Letters (Sep 2022)

Decoupled Land and Ocean Temperature Trends in the Early‐Middle Pleistocene

  • Hongxuan Lu,
  • Weiguo Liu,
  • Hong Yang,
  • Qin Leng,
  • Zhonghui Liu,
  • Yunning Cao,
  • Jing Hu,
  • Weijuan Sheng,
  • Huanye Wang,
  • Zheng Wang,
  • Zeke Zhang,
  • Youbin Sun,
  • Weijian Zhou,
  • Zhisheng An

DOI
https://doi.org/10.1029/2022GL099520
Journal volume & issue
Vol. 49, no. 17
pp. n/a – n/a

Abstract

Read online

Abstract Record of long‐term land temperature changes remains ephemeral, discontinuous, and isolated, thus leaving the common view that Pleistocene land temperature evolution should have followed ocean temperatures unconfirmed. Here, we present a continuous land surface temperature reconstruction in the Asian monsoon region over the past 3.0 Myr based on the distribution of soil bacterial lipids from the Chinese Loess Plateau. The land temperature record indicates an unexpected warming trend over the Pleistocene, which is opposite to the cooling trend in Pleistocene ocean temperatures, resulting in increased land‐sea thermal contrast. We propose that the previously unrecognized increase of land‐sea thermal contrast during much of the Pleistocene is a regional climate phenomenon that provides a likely mechanism in favor of the long‐term enhancement of the Pleistocene East Asian summer monsoon.