Temperature reconstruction from 10 to 120 kyr b2k from the NGRIP ice core

In order to reconstruct the temperature of the North Greenland Ice Core Project (NGRIP) site, new measurements of δ 15 N have been performed covering the time period from the beginning of the Holocene to Dansgaard–Oeschger (DO) event 8. Together with previously measured and mostly published δ 15 N d...

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Bibliographic Details
Published in:Climate of the Past
Main Authors: P. Kindler, M. Guillevic, M. Baumgartner, J. Schwander, A. Landais, M. Leuenberger
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2014
Subjects:
Environmental pollution
TD172-193.5
Environmental protection
TD169-171.8
Environmental sciences
GE1-350
Greenland
Greenland ice core
Greenland Ice core Project
ice core
Ice Sheet
NGRIP
North Greenland
North Greenland Ice Core Project
Online Access:https://doi.org/10.5194/cp-10-887-2014
https://doaj.org/article/dd23c0e2a4a1464ba46142beb7d47999
Description
Summary:In order to reconstruct the temperature of the North Greenland Ice Core Project (NGRIP) site, new measurements of δ 15 N have been performed covering the time period from the beginning of the Holocene to Dansgaard–Oeschger (DO) event 8. Together with previously measured and mostly published δ 15 N data, we present for the first time a NGRIP temperature reconstruction for the whole last glacial period from 10 to 120 kyr b2k (thousand years before 2000 AD) including every DO event based on δ 15 N isotope measurements combined with a firn densification and heat diffusion model. The detected temperature rises at the onset of DO events range from 5 °C (DO 25) up to 16.5 °C (DO 11) with an uncertainty of ±3 °C. To bring measured and modelled data into agreement, we had to reduce the accumulation rate given by the NGRIP ss09sea06bm timescale in some periods by 30 to 35%, especially during the last glacial maximum. A comparison between reconstructed temperature and δ 18 O ice data confirms that the isotopic composition of the stadial was strongly influenced by seasonality. We evidence an anticorrelation between the variations of the δ 18 O ice sensitivity to temperature (referred to as α) and obliquity in agreement with a simple Rayleigh distillation model. Finally, we suggest that α might be influenced by the Northern Hemisphere ice sheet volume.

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