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

Abstract

Abstract. In order to reconstruct the temperature of the North Greenland Ice Core Project (NGRIP) site, new measurements of δ15N 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 δ15N 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 δ15N 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 δ18Oice data confirms that the isotopic composition of the stadial was strongly influenced by seasonality. We evidence an anticorrelation between the variations of the δ18Oice 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.

Black Sea temperature response to glacial millennial‐scale climate variability

“…The mean annual Black Sea surface TEX 86 temperature record closely mimics the DO oscillations seen in the NGRIP Greenland ice core [Dansgaard et al, 1993;Kindler et al, 2014] (Figure 1a) and ranges between~5°C during stadials and~9°C during interstadials (today: 15°C). Our TEX 86 and Mg/Ca ostracods records suggest that HE and non-HE stadials cooled to about 5.5°C, with no significant difference between them.…”

“…Interstadial warming was shown to be strongest in Greenland [Kindler et al, 2014] and HE cooling most prominent in the midlatitude North Atlantic and western Mediterranean Sea [Bard et al, 2000;Martrat et al, 2004Martrat et al, , 2007. Climate models suggest that this spatial heterogeneity in the North Atlantic climate response was transmitted to the continental interior, with DO cycle temperature anomalies penetrating deeper into the continent than HE-associated cooling [Ganopolski and Rahmstorf, 2001;Zhang et al, 2014].…”

“…Climate conditions in Greenland and the Black Sea "Lake" during the last glacial (65-20 ka). (a) Greenland temperature [Kindler et al, 2014] (NGRIP); TEX 86 -based mean annual lake surface temperature (LST). The variability in bottom water temperature was estimated from the Mg/Ca of benthic ostracods, with ΔT reflecting a minimum estimate of the temperature changes [Bahr et al, 2008].…”

Stable isotope compositions of speleothems from the last interglacial – Spatial patterns of climate fluctuations in Europe

“…9A-C). This abrupt change may be related to an approximately 5 °C warming in Greenland (Kindler et al, 2014), which can be detected in small positive δ 18 O carb peaks in the BAR-II and the Schneckenloch and the Hölloch caves' records (Boch et al, 2011;Moseley et al, 2015). This peak is, however, negligible compared to the sudden δ 18 O carb decrease in the BAR-II stalagmite at 117 ka coupled with a rise in δ 13 C.…”

Dating, synthesis, and interpretation of palaeoclimatic records of the Last Glacial cycle and model-data integration: advances by the INTIMATE (INTegration of Ice-core, MArine and TErrestrial records) COST Action ES0907

“…The data have provided startling evidence not only of the amplitude of climate change over the last interglacial-glacial cycle, but also of the rapidity of those changes with, in many instances, temperatures shifting by more than 10˚C within decades (Johnsen et al, 1992;Kindler et al, 2014;NEEM community members, 2013;North Greenland Ice Core Project members, 2004;Steffensen et al, 2008).…”