Articles | Volume 10, issue 6
Clim. Past, 10, 2253–2261, 2014
Clim. Past, 10, 2253–2261, 2014

Research article 23 Dec 2014

Research article | 23 Dec 2014

Millennial meridional dynamics of the Indo-Pacific Warm Pool during the last termination

L. Lo1, C.-C. Shen1, K.-Y. Wei1, G. S. Burr2,1, H.-S. Mii3, M.-T. Chen4, S.-Y. Lee5, and M.-C. Tsai1 L. Lo et al.
  • 1High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan ROC
  • 2NSF-Arizona Accelerator Mass Spectrometry Facility, Department of Physics, University of Arizona, Tucson, AZ 85721, USA
  • 3Department of Earth Sciences, National Taiwan Normal University, Taipei 11677, Taiwan ROC
  • 4Institute of Applied Geosciences, National Taiwan Ocean University, Keelung 20224, Taiwan ROC
  • 5Research Center for Environmental Changes, Academia Sinica, Taipei 11529, Taiwan ROC

Abstract. To develop an in-depth understanding of the natural dynamics of the Indo-Pacific Warm Pool (IPWP) during the last deglaciation, stacked north- (N-) and south-IPWP (S-IPWP) thermal and hydrological records over the past 23–10.5 ka were built using planktonic foraminiferal geochemistry data from a new core, MD05-2925 (9.3° S, 151.5° E water depth 1661 m) in the Solomon Sea and eleven previous sites. Ice-volume-corrected seawater δ18O (δ18OSW-IVC) stacks show that S-IPWP δ18OSW-IVC values are indistinguishable from their northern counterparts through glacial time. The N-IPWP SST (sea surface temperature) stacked record features an increasing trend of 0.5 °C ka−1 since 18 ka. Its S-IPWP counterpart shows an earlier onset of temperature increase at 19 ka and a strong teleconnection to high-latitude climate in the Southern Hemisphere. Meridional SST gradients between the N- and S-IPWP were 1–1.5 °C during the Bølling/Allerød period and 1 °C during both Heinrich event 1 and the Younger Dryas, due to a warmer S-IPWP. A warm S-IPWP during the cold events could weaken the southern hemispheric branch of the Hadley cell and reduce precipitation in the Asian monsoon region.

Short summary
1. We have reconstructed new meridional thermal and precipitation stacked records in the Indo-Pacific Warm Pool (IPWP) during the last termination. 2. Meridional thermal gradient variations in the IPWP show tight links to the Northern Hemisphere millennial timescales event. 3. Anomalous warming in the south IPWP region could induce the southward shifting of the Intertropical Convergence Zone (ITCZ) in the IPWP during the Heinrich 1 and Younger Dryas events.