Do Greenland Ice Cores Reflect NW European Interglacial Climate Variations?

AbstractThe climatic evolution during the Eemian and the Holocene in western Europe is compared with the sea-surface conditions in the Norwegian Sea and with the oxygen-isotope-derived paleotemperature signal in the GRIP and Renland ice cores from Greenland. The records show a warm phase (ca. 3000 yr long) early in the Eemian (substage 5e). This suggests that the Greenland ice sheet, in general, recorded the climate in the region during this time. Rapid fluctuations during late stage 6 and late substage 5e in the GRIP ice core apparently are not recorded in the climatic proxies from western Europe and the Norwegian Sea. This may be due to low resolution in the terrestrial and marine records and/or long response time of the biotic changes. The early Holocene climatic optimum recorded in the terrestrial and marine records in the Norwegian Sea-NW European region is not found in the Summit (GRIP and GISP2) ice cores. However, this warm phase is recorded in the Renland ice core. Due to the proximity of Renland to the Norwegian Sea, this area is probably more influenced by changes in polar front positions which may partly explain this discrepancy. A reduction in the elevation at Summit during the Holocene may, however, be just as important. The high-amplitude shifts during substage 5e in the GRIP core could be due to Atlantic water oscillating closer to, and also reaching, the coast of East Greenland. During the Holocene, Atlantic water was generally located farther east in the Norwegian Sea than during the Eemian.

Download Full-text

Tracing the depth of the Holocene ice in North Greenland from radio-echo sounding data

Annals of Glaciology ◽

10.3189/2013aog64a057 ◽

2013 ◽

Vol 54 (64) ◽

pp. 44-50 ◽

Cited By ~ 25

Author(s):

Nanna B. Karlsson ◽

Dorthe Dahl-Jensen ◽

S. Prasad Gogineni ◽

John D. Paden

Keyword(s):

Ice Core ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Ice Cores ◽

The Holocene ◽

Fitting Method ◽

Radio Echo Sounding ◽

North Greenland ◽

Echo Sounding

Abstract Radio-echo sounding surveys over the Greenland ice sheet show clear, extensive internal layering, and comparisons with age–depth scales from deep ice cores allow for dating of the layering along the ice divide. We present one of the first attempts to extend the dated layers beyond the ice core drill sites by locating the depth of the Bølling–Allerød transition in >400 flight-lines using an automated fitting method. Results show that the transition is located in the upper one-third of the ice column in the central part of North Greenland, while the transition lowers towards the margin. This pattern mirrors the present surface accumulation, and also indicates that a substantial amount of pre-Holocene ice must be present in central North Greenland.

Download Full-text

Major dust events in Europe during marine isotope stage 5 (130–74 ka): a climatic interpretation of the "markers"

Climate of the Past ◽

10.5194/cp-9-2213-2013 ◽

2013 ◽

Vol 9 (5) ◽

pp. 2213-2230 ◽

Cited By ~ 14

Author(s):

D.-D. Rousseau ◽

M. Ghil ◽

G. Kukla ◽

A. Sima ◽

P. Antoine ◽

...

Keyword(s):

Western Europe ◽

Ice Core ◽

Sediment Cores ◽

Ice Cores ◽

Fine Sand ◽

Polar Front ◽

Dust Storms ◽

Marine Isotope Stage ◽

Climate Projections ◽

Dust Events

Abstract. At present, major dust storms are occurring at mid-latitudes in the Middle East and Asia, as well as at low latitudes in Northern Africa and in Australia. Western Europe, though, does not experience such dramatic climate events, except for some African dust reaching it from the Sahara. This modern situation is of particular interest, in the context of future climate projections, since the present interglacial is usually interpreted, in this context, as an analog of the warm Eemian interval. European terrestrial records show, however, major dust events during the penultimate interglacial and early glacial. These events are easily observed in loess records by their whitish-color deposits, which lie above and below dark chernozem paleosols in Central European records of Marine Isotope Stage (MIS) 5 age. We describe here the base of the Dolni Vestonice (DV) loess sequence, Czech Republic, as the reference of such records. The dust is deposited during intervals that are characterized by poor vegetation – manifested by high δ13C values and low magnetic susceptibility – while the fine sand and clay in the deposits shows grain sizes that are clearly different from the overlying pleniglacial loess deposits. Some of these dust events have been previously described as "Markers" or Marker Silts (MS) by one of us (G. Kukla), and are dated at about 111–109 ka and 93–92 ka, with a third and last one slightly visible at about 75–73 ka. Other events correspond to the loess material of Kukla's cycles, and are described as eolian silts (ES); they are observed in the same DV sequence and are dated at about 106–105 ka, 88–86 ka, and 78.5–77 ka. These dates are determined by considering the OSL ages with their errors measured on the studied sequence, and the comparison with Greenland ice-core and European speleothem chronologies. The fine eolian deposits mentioned above, MS as well as ES, correspond to short events that lasted about 2 ka; they are synchronous with re-advances of the polar front over the North Atlantic, as observed in marine sediment cores. These deposits also correlate with important changes observed in European vegetation. Some ES and MS events appear to be coeval with significant dust peaks recorded in the Greenland ice cores, while others are not. This decoupling between the European eolian and Greenland dust depositions is of considerable interest, as it differs from the fully glacial situation, in which the Eurasian loess sedimentation mimics the Greenland dust record. Previous field observations supported an interpretation of MS events as caused by continental dust storms. We show here, by a comparison with speleothems of the same age found in the northern Alps, that different atmospheric-circulation modes seem to be responsible for the two categories of dust events, MS vs. ES.

Download Full-text

Synchronizing the Greenland ice core and radiocarbon timescales over the Holocene – Bayesian wiggle-matching of cosmogenic radionuclide records

Climate of the Past ◽

10.5194/cp-12-15-2016 ◽

2016 ◽

Vol 12 (1) ◽

pp. 15-30 ◽

Cited By ~ 38

Author(s):

F. Adolphi ◽

R. Muscheler

Keyword(s):

Statistical Approach ◽

Ice Core ◽

Ice Cores ◽

The Holocene ◽

Counting Error ◽

Climate Reconstructions ◽

Uncertainty Measurement ◽

Uncertainty Estimates ◽

Paleoclimate Records ◽

Cosmogenic Radionuclide

Abstract. Investigations of past climate dynamics rely on accurate and precise chronologies of the employed climate reconstructions. The radiocarbon dating calibration curve (IntCal13) and the Greenland ice core chronology (GICC05) represent two of the most widely used chronological frameworks in paleoclimatology of the past ∼  50 000 years. However, comparisons of climate records anchored on these chronologies are hampered by the precision and accuracy of both timescales. Here we use common variations in the production rates of 14C and 10Be recorded in tree-rings and ice cores, respectively, to assess the differences between both timescales during the Holocene. Compared to earlier work, we employ a novel statistical approach which leads to strongly reduced and yet, more robust, uncertainty estimates. Furthermore, we demonstrate that the inferred timescale differences are robust independent of (i) the applied ice core 10Be records, (ii) assumptions of the mode of 10Be deposition, as well as (iii) carbon cycle effects on 14C, and (iv) in agreement with independent estimates of the timescale differences. Our results imply that the GICC05 counting error is likely underestimated during the most recent 2000 years leading to a dating bias that propagates throughout large parts of the Holocene. Nevertheless, our analysis indicates that the GICC05 counting error is generally a robust uncertainty measurement but care has to be taken when treating it as a nearly Gaussian error distribution. The proposed IntCal13-GICC05 transfer function facilitates the comparison of ice core and radiocarbon dated paleoclimate records at high chronological precision.

Download Full-text

Brief communication: New evidence further constraining Tibetan ice core chronologies to the Holocene

The Cryosphere ◽

10.5194/tc-15-2109-2021 ◽

2021 ◽

Vol 15 (4) ◽

pp. 2109-2114

Author(s):

Shugui Hou ◽

Wangbin Zhang ◽

Ling Fang ◽

Theo M. Jenk ◽

Shuangye Wu ◽

...

Keyword(s):

Tibetan Plateau ◽

Ice Core ◽

Ice Cores ◽

Qilian Mountains ◽

Time Range ◽

The Holocene ◽

Guliya Ice Core ◽

Considerable Controversy ◽

New Evidence

Abstract. There is considerable controversy regarding the age ranges of Tibetan ice cores. The Guliya ice core was reported to reach as far back as ∼760 ka (kiloannum, i.e. 1000 years), whereas chronologies of all other Tibetan cores cover at most the Holocene. Here we present ages for two new ice cores reaching bedrock, from the Zangser Kangri (ZK) glacier in the northwestern Tibetan Plateau and the Shulenanshan (SLNS) glacier in the western Qilian Mountains. We estimated bottom ages of 8.90±0.570.56 ka and 7.46±1.461.79 ka for the ZK and SLNS ice core respectively, further constraining the time range accessible by Tibetan ice cores to the Holocene.

Download Full-text

The Elbrus (Caucasus, Russia) ice core record – Part 1: reconstruction of past anthropogenic sulfur emissions in south-eastern Europe

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-14119-2019 ◽

2019 ◽

Vol 19 (22) ◽

pp. 14119-14132 ◽

Cited By ~ 3

Author(s):

Susanne Preunkert ◽

Michel Legrand ◽

Stanislav Kutuzov ◽

Patrick Ginot ◽

Vladimir Mikhalenko ◽

...

Keyword(s):

Eastern Europe ◽

Western Europe ◽

Ice Core ◽

Ice Cores ◽

Fold Increase ◽

South Eastern ◽

Basal Ice ◽

Ice Core Record ◽

South Eastern Europe ◽

The 19Th Century

Abstract. This study reports on the glaciochemistry of a deep ice core (182 m long) drilled in 2009 at Mount Elbrus in the Caucasus, Russia. Radiocarbon dating of the particulate organic carbon fraction in the ice suggests that the basal ice dates to 280±400 CE (Common Era). Based on chemical stratigraphy, the upper 168.6 m of the core was dated by counting annual layers. The seasonally resolved chemical records cover the years 1774–2009 CE, thus being useful to reconstruct many aspects of atmospheric pollution in south-eastern Europe from pre-industrial times to the present day. After having examined the extent to which the arrival of large dust plumes originating from the Sahara and Middle East modifies the chemical composition of the Elbrus (ELB) snow and ice layers, we focus on the dust-free sulfur pollution. The ELB dust-free sulfate levels indicate a 6- and 7-fold increase from 1774–1900 to 1980–1995 in winter and summer, respectively. Remaining close to 55±10 ppb during the 19th century, the annual dust-free sulfate levels started to rise at a mean rate of ∼3 ppb per year from 1920 to 1950. The annual increase accelerated between 1950 and 1975 (8 ppb per year), with levels reaching a maximum between 1980 and 1990 (376±10 ppb) and subsequently decreasing to 270±18 ppb at the beginning of the 21st century. Long-term dust-free sulfate trends observed in the ELB ice cores are compared with those previously obtained in Alpine and Altai (Siberia) ice, with the most important differences consisting in a much earlier onset and a more pronounced decrease in the sulfur pollution over the last 3 decades in western Europe than south-eastern Europe and Siberia.

Download Full-text

Tracer transport in an isochronal ice-sheet model

Journal of Glaciology ◽

10.1017/jog.2016.111 ◽

2016 ◽

Vol 63 (237) ◽

pp. 22-38 ◽

Cited By ~ 3

Author(s):

ANDREAS BORN

Keyword(s):

Ice Core ◽

Ice Sheet ◽

Vertical Motion ◽

Greenland Ice Sheet ◽

Ice Cores ◽

Model Parameters ◽

Tracer Transport ◽

Geochemical Tracers ◽

Tuning Method ◽

Polar Ice Sheets

ABSTRACTThe full history of ice sheet and climate interactions is recorded in the vertical profiles of geochemical tracers in polar ice sheets. Numerical simulations of these archives promise great advances both in the interpretation of these reconstructions and the validation of the models themselves. However, fundamental mathematical shortcomings of existing models subject tracers to spurious diffusion, thwarting straightforward solutions. Here, I propose a new vertical discretization for ice-sheet models that eliminates numerical diffusion entirely. Vertical motion through the model mesh is avoided by mimicking the real-world flow of ice as a thinning of underlying layers. A new layer is added to the surface at equidistant time intervals, isochronally, thus identifying each layer uniquely by its time of deposition and age. This new approach is implemented for a two-dimensional section through the summit of the Greenland ice sheet. The ability to directly compare simulations of vertical ice cores with reconstructed data is used to find optimal model parameters from a large ensemble of simulations. It is shown that because this tuning method uses information from all times included in the ice core, it constrains ice-sheet sensitivity more robustly than a realistic reproduction of the modern ice-sheet surface.

Download Full-text

Some comments on climatic reconstructions from ice cores drilled in areas of high melt

Journal of Glaciology ◽

10.1017/s0022143000002847 ◽

1997 ◽

Vol 43 (143) ◽

pp. 90-97 ◽

Cited By ~ 74

Author(s):

Roy M. Koerner

Keyword(s):

Time Scales ◽

Ice Core ◽

Ice Cores ◽

The Holocene ◽

Ice Caps ◽

Ice Cap ◽

Thermal Maximum ◽

Devon Ice Cap ◽

Seasonal Signals ◽

Cross Correlations

AbstractPoor consideration has been given in many Arctic circum-polar ice-core studies to the effect of summer snow melt on chemistry, stable-isotope concentrations and time-scales. Many of these corps are drilled close to the firn line where melt is intense. Some come from below the firn line where accumulation is solely in the form of super-imposed ice. In all cases, seasonal signals are reduced or removed and, in some, time gaps develop during periods of excessive melting which situate the drill site in the ablation zone. Consequently, cross correlations of assumed synchronous events among the cores are invalid, so that time-scales along the same cores differ between authors by factors of over 2. Many so-called climatic signals are imaginary rather than real. By reference to published analyses of cores from the superimposed ice zone on Devon Ice Cap (Koerner, 1970) and Meighen Ice Cap (Koerner and Paterson, 1974), it is shown how melt affects all the normally well-established ice-core proxies and leads to their misinterpretation. Despite these limitations, the cores can give valuable low-resolution records for all or part of the Holocene. They show that the thermal maximum in the circum-polar Arctic occurred in the early Holocene. This maximum, effected negative balances on all the ice caps and removed the smaller ones. Cooler conditions in the second half of the Holocene have caused the regrowth of these same ice caps.

Download Full-text

High-resolution mineral dust and sea ice proxy records from the Talos Dome ice core

Climate of the Past ◽

10.5194/cp-9-2789-2013 ◽

2013 ◽

Vol 9 (6) ◽

pp. 2789-2807 ◽

Cited By ~ 18

Author(s):

S. Schüpbach ◽

U. Federer ◽

P. R. Kaufmann ◽

S. Albani ◽

C. Barbante ◽

...

Keyword(s):

Southern Ocean ◽

Sea Ice ◽

Ross Sea ◽

Transport Model ◽

Mineral Dust ◽

Ice Core ◽

Ice Cores ◽

Last Interglacial ◽

The Holocene ◽

Proxy Records

Abstract. In this study we report on new non-sea salt calcium (nssCa2+, mineral dust proxy) and sea salt sodium (ssNa+, sea ice proxy) records along the East Antarctic Talos Dome deep ice core in centennial resolution reaching back 150 thousand years (ka) before present. During glacial conditions nssCa2+ fluxes in Talos Dome are strongly related to temperature as has been observed before in other deep Antarctic ice core records, and has been associated with synchronous changes in the main source region (southern South America) during climate variations in the last glacial. However, during warmer climate conditions Talos Dome mineral dust input is clearly elevated compared to other records mainly due to the contribution of additional local dust sources in the Ross Sea area. Based on a simple transport model, we compare nssCa2+ fluxes of different East Antarctic ice cores. From this multi-site comparison we conclude that changes in transport efficiency or atmospheric lifetime of dust particles do have a minor effect compared to source strength changes on the large-scale concentration changes observed in Antarctic ice cores during climate variations of the past 150 ka. Our transport model applied on ice core data is further validated by climate model data. The availability of multiple East Antarctic nssCa2+ records also allows for a revision of a former estimate on the atmospheric CO2 sensitivity to reduced dust induced iron fertilisation in the Southern Ocean during the transition from the Last Glacial Maximum to the Holocene (T1). While a former estimate based on the EPICA Dome C (EDC) record only suggested 20 ppm, we find that reduced dust induced iron fertilisation in the Southern Ocean may be responsible for up to 40 ppm of the total atmospheric CO2 increase during T1. During the last interglacial, ssNa+ levels of EDC and EPICA Dronning Maud Land (EDML) are only half of the Holocene levels, in line with higher temperatures during that period, indicating much reduced sea ice extent in the Atlantic as well as the Indian Ocean sector of the Southern Ocean. In contrast, Holocene ssNa+ flux in Talos Dome is about the same as during the last interglacial, indicating that there was similar ice cover present in the Ross Sea area during MIS 5.5 as during the Holocene.

Download Full-text

Interglacial climates: Advances in our understanding of warm climate episodes

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133310386869 ◽

2010 ◽

Vol 34 (6) ◽

pp. 845-856 ◽

Cited By ~ 8

Author(s):

Danielle Schreve ◽

Ian Candy

Keyword(s):

Western Europe ◽

Ice Sheets ◽

Ice Cores ◽

Temperate Climate ◽

Warm Climate ◽

Climatic Evolution ◽

Extreme Cold ◽

New Research ◽

Continental Ice Sheets ◽

Shed Light

The Quaternary is characterized by the alternation of relatively brief periods of temperate climate (interglacials) with episodes of extreme cold, often with the build-up of extensive continental ice sheets. Over the last decade, new research has revealed far greater complexity and diversity in the interglacial record than previously recognized, with temperate-climate episodes of markedly different duration, stability and intensity. These findings not only shed light on the climatic parameters behind changing floras and faunas during the Pleistocene but also aid our understanding of climatic evolution during the Holocene (the current interglacial), in particular the search for the most appropriate past analogues. In this progress report, we review the basis for interglacial complexity, drawing upon the evidence from long continuous terrestrial records in the Mediterranean, Antarctic ice cores and river terrace sequences in western Europe, before using the details of the British Quaternary interglacial record as an example of how marine and terrestrial records can be linked.

Download Full-text

First continuous high-resolution aerosol record from the East Greenland Ice Core Project (EGRIP), covering the last 15,000 years

10.5194/egusphere-egu2020-15202 ◽

2020 ◽

Author(s):

Camilla Marie Jensen ◽

Tobias Erhardt ◽

Giulia Sinnl ◽

Hubertus Fischer

Keyword(s):

High Resolution ◽

Biomass Burning ◽

Forest Fires ◽

Ice Core ◽

Greenland Ice Sheet ◽

Ice Cores ◽

Background Level ◽

Volcanic Eruptions ◽

Atmospheric Conditions ◽

Data Set

Ice sheets are reliable archives of atmospheric impurities such as aerosols and gasses of both natural and anthropogenic origin. Impurity records from Greenland ice cores reveal much information about previous atmospheric conditions and long-range transport in the Northern hemisphere going back more than a hundred thousand years.Here we present the data from the upper 1,411 m from the EGRIP ice core, measuring conductivity, dust, sodium, calcium, ammonium, and nitrate. These records contain information about ocean sources, transport of terrestrial dust, soil and vegetation emissions as well as biomass burning, volcanic eruptions, etc., covering approximately the past 15,000 years. This newly obtained data set is unique as it provides the first high-resolution information about several thousands of years of the mid-Holocene period in Greenland that none of the previous impurity records from the other deep Greenland ice cores had managed to cover before due to brittle ice. This will contribute to further understanding of the atmospheric conditions for the pre-industrial period.The ammonium record contains peaks significantly higher than the background level. These peaks are caused by biomass burning or forest fires emitting plumes of ammonia large enough so that they can extend to the free troposphere and be efficiently transported all the way to the Greenland ice sheet. Here we present preliminary results of the wild fire frequency covering the entire Holocene, where the wild fires are defined as outliers in the ammonium record of annual means.

Download Full-text