Proxy and simulation data for marine sediment core MD01-2414 from the central Okhotsk Sea

Recent reduction in high-latitude sea ice extent demonstrates that sea ice is highly sensitive to external and internal radiative forcings. In order to better understand sea ice system responses to external orbital forcing and internal oscillations on orbital timescales, here we reconstruct changes...

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Bibliographic Details
Main Authors: Lo, Li, Belt, Simon T, Lattaud, Julie, Friedrich, Tobias, Zeeden, Christian, Schouten, Stefan, Smik, Lukas, Timmermann, Axel, Cabedo-Sanz, Patricia, Huang, Jyh-Jaan, Zhou, Liping, Ou, Tsong-Hua, Chang, Yuan-Pin, Wang, Liang-Chi, Chou, Yu-Min, Shen, Chuan-Chou, Chen, Min-Te, Wei, Kuo-Yen, Song, Sheng-Rong, Fang, Tien-Hsi, Gorbarenko, Sergey A, Wang, Wei-Lung, Lee, Teh-Quei, Elderfield, Henry, Hodell, David A
Format: Other/Unknown Material
Language:English
Published: PANGAEA 2018
Subjects:
Giant piston corer
GPC
IMAGES VII - WEPAMA
Marion Dufresne (1995)
MD012414
MD01-2414
MD122
Sea of Ochotsk
Okhotsk
okhotsk sea
Sea ice
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.886808
https://doi.org/10.1594/PANGAEA.886808
Description
Summary:Recent reduction in high-latitude sea ice extent demonstrates that sea ice is highly sensitive to external and internal radiative forcings. In order to better understand sea ice system responses to external orbital forcing and internal oscillations on orbital timescales, here we reconstruct changes in sea ice extent and summer sea surface temperature (SSST) over the past 130,000 yrs in the central Okhotsk Sea. We applied novel organic geochemical proxies of sea ice (IP25), SSST (TEXL86) and open water marine productivity (a tri-unsaturated highly branched isoprenoid and biogenic opal) to marine sediment core MD01-2414 (53°11.77'N, 149°34.80'E, water depth 1123 m). To complement the proxy data, we also carried out transient Earth system model simulations and sensitivity tests to identify contributions of different climatic forcing factors. Our results show that the central Okhotsk Sea was ice-free during Marine Isotope Stage (MIS) 5e and the early-mid Holocene, but experienced variable sea ice cover during MIS 2-4, consistent with intervals of relatively high and low SSST, respectively. Our data also show that the sea ice extent was governed by precession-dominated insolation changes during intervals of atmospheric CO2 concentrations ranging from 190 to 260 ppm. However, the proxy record and the model simulation data show that the central Okhotsk Sea was near ice-free regardless of insolation forcing throughout the penultimate interglacial, and during the Holocene, when atmospheric CO2 was above ~260 ppm. Past sea ice conditions in the central Okhotsk Sea were therefore strongly modulated by both orbital-driven insolation and CO2-induced radiative forcing during the past glacial/interglacial cycle.

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