10:15 〜 10:30
[MIS16-16] Variation of the North Pacific Ocean circulation during the Late Pleistocene glacial-interglacial cycles
キーワード：北太平洋、氷期−間氷期サイクル、水温復元
The Late Pleistocene glacial-interglacial (G-IG) cycle, characterized by 100 kyr variations in global ice volume and atmospheric CO2 concentration, governs the global climate (e.g., global mean surface temperature). Reported long-term SST records in the Equatorial and North Pacific show a unique response to the orbital forcing, despite their overall patterns reflecting the G-IG cycle. This suggests the reorganization of the ocean-atmosphere circulation in the region associated with the G-IG cycle. However, available SST records in the subarctic region of the North Pacific are limited to the Last Glacial Maxima. Therefore, the whole picture of the North Pacific response to global climate change remains unclear.
In this study, we reconstructed changes in sea surface temperature (SST) at the western and eastern margins of the North Pacific subarctic region for the past 470 kyrs based on TEX86L and UK37’ analyses in Ocean Drilling Program (ODP) Sites ODP 882 and 887. The SST records in Sites 882 and 887 during the last glacial cycle show a typical G-IG pattern. This correspondence confirms the robustness of our reconstruction. However, extended SST records back to 470 ka revealed a unique response to the orbital forcing with relatively low SSTs during the super interglacials compared to the Holocene. The subarctic region's unique response appears to be linked climate variation in the low latitude Pacific, implying large-scale reorganization of the ocean-atmosphere circulation associated with the global climate change.
In this study, we reconstructed changes in sea surface temperature (SST) at the western and eastern margins of the North Pacific subarctic region for the past 470 kyrs based on TEX86L and UK37’ analyses in Ocean Drilling Program (ODP) Sites ODP 882 and 887. The SST records in Sites 882 and 887 during the last glacial cycle show a typical G-IG pattern. This correspondence confirms the robustness of our reconstruction. However, extended SST records back to 470 ka revealed a unique response to the orbital forcing with relatively low SSTs during the super interglacials compared to the Holocene. The subarctic region's unique response appears to be linked climate variation in the low latitude Pacific, implying large-scale reorganization of the ocean-atmosphere circulation associated with the global climate change.