scholarly journals Ultra-high resolution snapshots of three multi-decadal periods in an Antarctic ice core

2016 ◽  
Vol 62 (231) ◽  
pp. 31-36 ◽  
Author(s):  
SKYLAR A. HAINES ◽  
PAUL A. MAYEWSKI ◽  
ANDREI V. KURBATOV ◽  
KIRK A. MAASCH ◽  
SHARON B. SNEED ◽  
...  
Keyword(s):  
High Resolution ◽  
Inductively Coupled Plasma ◽  
Decadal Variability ◽  
Ice Core ◽  
Late Glacial ◽  
Snow Accumulation ◽  
High Resolution Data ◽  
Annual Layer ◽  
Age Model ◽  
Chemical Inputs

ABSTRACTWe offer the first sub-seasonal view of glacial age archives from the Siple Dome-A (SDMA) ice core using the ultra-high resolution capabilities of a newly developed laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS; 121 µm sampling resolution) system capable of conducting multi-element glaciochemical analysis. Our ultra-high resolution data demonstrates that: (1) the SDMA ice core record can be annually dated based on seasonality in chemical inputs at a depth not previously possible using previous glaciochemical sampling methods, (2) winter accumulation at the SD site was greater than summer accumulation during the three late glacial periods selected (~15.3, 17.3, 21.4 Ka ago) in this study and (3) resulting annual layer thicknesses results show greater variability than the current SD ice core depth/age model (Brook and others, 2005), possibly due to depositional effects such as wind scouring and/or decadal variability in snow accumulation that is not captured by the resolution of the current depth/age model.

scholarly journals A comparison of annual layer thickness model estimates with observational measurements using the Berkner Island ice core, Antarctica

2017 ◽  
Vol 29 (4) ◽  
pp. 382-393
Author(s):  
A. Massam ◽  
S.B. Sneed ◽  
G.P. Lee ◽  
R.R. Tuckwell ◽  
R. Mulvaney ◽  
...  
Keyword(s):  
High Resolution ◽  
Layer Thickness ◽  
Inductively Coupled Plasma ◽  
Ice Core ◽  
Ultra Violet ◽  
Analytical Techniques ◽  
Inductively Coupled ◽  
Annual Layer ◽  
Icp Ms ◽  
Chemical Profiles

AbstractA model to estimate the annual layer thickness of deposited snowfall at a deep ice core site, compacted by vertical strain with respect to depth, is assessed using ultra-high-resolution laboratory analytical techniques. A recently established technique of high-resolution direct chemical analysis of ice using ultra-violet laser ablation inductively-coupled plasma mass spectrometry (LA ICP-MS) has been applied to ice from the Berkner Island ice core, and compared with results from lower resolution techniques conducted on parallel sections of ice. The results from both techniques have been analysed in order to assess the capability of each technique to recover seasonal cycles from deep Antarctic ice. Results do not agree with the annual layer thickness estimates from the age–depth model for individual samples <1 m long as the model cannot reconstruct the natural variability present in annual accumulation. However, when compared with sections >4 m long, the deviation between the modelled and observational layer thicknesses is minimized to within two standard deviations. This confirms that the model is capable of successfully estimating mean annual layer thicknesses around analysed sections. Furthermore, our results confirm that the LA ICP-MS technique can reliably recover seasonal chemical profiles beyond standard analytical resolution.

Representativeness of decadal-scale climate signals in ice-core aerosol records

2020 ◽  
Author(s):  
Tobias Erhardt ◽  
Camilla Jensen ◽  
Maria Hörhold ◽  
Hubertus Fischer
Keyword(s):  
High Resolution ◽  
Time Scales ◽  
Decadal Variability ◽  
Ice Core ◽  
Ice Cores ◽  
Aerosol Deposition ◽  
High Temporal Resolution ◽  
Annual Layer ◽  
Decadal Scale ◽  
Climate Signals

&lt;p&gt;Records of past aerosol deposition to the polar ice sheets have enabled us to study variability in different parts of the earth system in great temporal detail over past glacial cycles. Furthermore, the high temporal resolution of ice-core aerosol records has been the basis for precise dating of climate records using annual layer counting. Nonetheless, the intermittent character of show deposition and especially the redistribution of snow on the surface of the ice sheet intrinsically affects the preservation of climate signals in the ice. This strongly limits how representative a climate record from a single ice core can be. It has been well established that even though seasonal variability might be preserved in an ice-core aerosol record, the inter annual variability of that record is different from a different core from the same site.&lt;/p&gt;&lt;p&gt;Until now most of the investigations have focused on inter annual representatives. This is mostly due to limited sample availability as multiple long records are needed for investigations on longer time scales. However, with the prospect of new high-resolution records over the Holocene from the EastGRIP ice core, understanding the representativeness of this record on decadal time scales is an important question. To tackle this problem, we use high-resolution aerosol records from multiple closely spaced ice cores from the EastGRIP deep ice core drill site. The records approximately cover the last millennium and are sub-seasonally resolved enabling the study of interannual to decadal variability over multiple aerosol species. All records are dated using annual layer counting and cross dating to the EastGRIP deep ice core using volcanic match points. In the presented pilot study, we focus on records of sea-salt and dust related aerosol species as well as on episodic aerosol signals from volcanos and wildfires.&lt;/p&gt;

scholarly journals A revised Law Dome age model (LD2017) and implications for last glacial climate

2017 ◽  
Author(s):  
Jason Roberts ◽  
Andrew Moy ◽  
Christopher Plummer ◽  
Tas van Ommen ◽  
Mark Curran ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Ice Core ◽  
Chemical Species ◽  
Linear Interpolation ◽  
Snow Accumulation ◽  
Volcanic Event ◽  
Last Glacial ◽  
Annual Layer ◽  
Abrupt Changes ◽  
Age Model

Abstract. Here we present a revised Law Dome, Dome Summit South (DSS) ice core age model (denoted LD2017) that significantly improves the chronology over the last 88 ka. An ensemble approach was used, allowing for the computation of both a median age and associated uncertainty as a function of depth. The revised chronology incorporates extended continuous annual layer counting to 853 m using chemical species with seasonally-varying behaviours. The annual layer counted age at 853 m is 2332 years before 2000 (y b2k) with an error of &amp;plus;13/−7 y, i.e. 2345–2325 y b2k . Below this depth, non-linear interpolation between age ties using a probability density function for age/depth is used to constrain and model the age of the ice. The ice-based age ties below the annual layer counted section are based on matching volcanic event markers, methane (CH4) gas concentration, isotopic composition of ice (δ18O) and the Last Glacial Maximum (LGM) dust peak to other records. For consistency, the timescale used for all matching is the AICC2012 timescale (Veres et al., 2013). The first ice-based age tie is the base of the annual layer counting record (2332 y b2k) and the age ties from ~ 2400–4000 y b2k are volcanic synchronised ice-based age ties. The detection of abrupt changes in CH4 gas concentrations within the DSS record provides further independent gas-based age ties, including the tightly constrained 8200 y b2k event. The improved age control between 9000 and 21000 y b2k is supplemented by CH4 and δ18O ice measurements (Pedro et al., 2011). Over the period 16600 to 18600 y b2k large changes in dust concentration, matched to the EDC dust record, are used to constrain two ice-based age ties. Unlike previous studies, where the modelling was used to simultaneously infer both age and snow accumulation rate, we made an independent estimate of the snow accumulation rate, where required, for the use of gas based age ties.

scholarly journals 2000 years of annual ice core data from Law Dome, East Antarctica

2022 ◽  
Author(s):  
Lenneke M. Jong ◽  
Christopher T. Plummer ◽  
Jason L. Roberts ◽  
Andrew D. Moy ◽  
Mark A. J. Curran ◽  
...  
Keyword(s):  
High Resolution ◽  
Ice Core ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Water Isotopes ◽  
Stable Water Isotopes ◽  
High Resolution Data ◽  
Data Centre ◽  
Level 1 ◽  
Resolution Data

Abstract. Ice core records from Law Dome in East Antarctica, collected over the the last three decades, provide high resolution data for studies of the climate of Antarctica, Australia and the Southern and Indo-Pacific Oceans. Here we present a set of annually dated records of trace chemistry, stable water isotopes and snow accumulation from Law Dome covering over the period from −11 to 2017 CE (1961 to −66 BP 1950), as well as the level 1 chemistry data from which the annual chemistry records are derived. This dataset provides an update and extensions both forward and back in time of previously published subsets of the data, bringing them together into a coherent set with improved dating. The data are available for download from the Australian Antarctic Data Centre at https://doi.org/10.26179/5zm0-v192.

scholarly journals 1000 year ice-core records from Berkner Island, Antarctica

2002 ◽  
Vol 35 ◽  
pp. 45-51 ◽  
Author(s):  
Robert Mulvaney ◽  
Hans Oerter ◽  
David A. Peel ◽  
Wolfgang Graf ◽  
Carol Arrowsmith ◽  
...  
Keyword(s):  
Decadal Variability ◽  
Ice Core ◽  
Ice Cores ◽  
Aerosol Deposition ◽  
Climate History ◽  
Joint Project ◽  
The Past ◽  
Annual Layer ◽  
History Of ◽  
Field Season

AbstractTwo medium-depth ice cores were retrieved from Berkner Island by a joint project between the Alfred-Wegener-Institut and the British Antarctic Survey in the 1994/95 field season. A 151m deep core from the northern dome (Reinwarthhöhe) of Berkner Island spans 700 years, while a 181 m deep core from the southern dome (Thyssenhöhe) spans approximately 1200 years. Both cores display clear seasonal cycles in electrical conductivity measurements, allowing dating by annual-layer counting and the calculation of accumulation profiles. Stable-isotope measurements (both δ18O and δD), together with the accumulation data, allow us to estimate changes in climate for most of the past millennium: the data show multi-decadal variability around a generally stable long-termmean. In addition, a full suite of major chemistry measurements is available to define the history of aerosol deposition at these sites: again, there is little evidence that the chemistry of the sites has changed over the past six centuries. Finally, we suggest that the southern dome, with an ice thickness of 950 m, is an ideal site from which to gain a climate history of the late stages of the last glacial and the deglaciation for comparison with the records from the deep Antarctic ice cores, and with other intermediate-depth cores such as Taylor Dome and Siple Dome.

Towards an improved understanding of high-resolution impurity signals in deep Antarctic ice cores

2020 ◽  
Author(s):  
Pascal Bohleber ◽  
Marco Roman ◽  
Carlo Barbante ◽  
Barbara Stenni ◽  
Barbara Delmonte
Keyword(s):  
Laser Ablation ◽  
High Resolution ◽  
Inductively Coupled Plasma ◽  
Ice Core ◽  
Ice Cores ◽  
Inductively Coupled ◽  
Icp Ms ◽  
First Results ◽  
Plasma Mass Spectrometry ◽  
Fine Resolution

&lt;p&gt;Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) offers minimally destructive ice core impurity analysis at micron-scale resolution. This technique is especially suited for exploring closely spaced layers of ice within samples collected at low accumulation sites or in regions of highly compressed and thinned ice. Accordingly, LA-ICP-MS promises invaluable insights in the analysis of a future &amp;#8220;Oldest ice core&amp;#8221; from Antarctica. However, in contrast to ice core melting techniques, taking into account the location of impurities is crucial to avoid misinterpretation of ultra-fine resolution signals obtained from newly emerging laser ablation technologies. Here we present first results from a new LA-ICP-MS setup developed at the University of Venice, based on a customized two-volume cryogenic ablation chamber optimized for fast wash-out times. We apply our method for high-resolution chemical imagining analysis of impurities in samples from intermediate and deep sections of the Talos Dome and EPICA Dome C ice cores. We discuss the localization of both soluble and insoluble impurities within the ice matrix and evaluate the spatial significance of a single profile along the main core axis. With this, we aim at establishing a firm basis for a future deployment of the LA-ICP-MS in an &amp;#8220;Oldest Ice Core&amp;#8221;. Moreover, our work illustrates how LA-ICP-MS may offer new means to study the impurity-microstructure interplay in deep polar ice, thereby promising to advance our understanding of these fundamental processes.&lt;/p&gt;

scholarly journals The calcium-dust relationship in high-resolution data from Dome C, Antarctica

2011 ◽  
Vol 7 (2) ◽  
pp. 1113-1137 ◽  
Author(s):  
F. Lambert ◽  
M. Bigler ◽  
J. P. Steffensen ◽  
M. Hutterli ◽  
H. Fischer
Keyword(s):  
High Resolution ◽  
Ice Core ◽  
Calcium Content ◽  
Depth Resolution ◽  
Dust Particles ◽  
Radiation Balance ◽  
High Resolution Data ◽  
The Past ◽  
Low Correlation ◽  
Soluble Calcium

Abstract. Ice core data from Antarctica provide detailed insights into the characteristics of past climate, atmospheric circulation, as well as changes in the aerosol load of the atmosphere. We present high-resolution records of soluble calcium (Ca2+), non-sea-salt soluble calcium (nssCa2+), and insoluble mineral aerosol dust from the East Antarctic Plateau at a depth resolution of 1 cm, spanning the past 800 000 yr. The comparison shows that the ratio of ionic proxies such as CaCa2+ (or nssCa2+) to particulate dust aerosol is variable in time. Accordingly, the insoluble dust record is representative of large and small atmospheric particulate dust load changes and better suited to quantify the aerosol effect on the radiation balance in the past. In contrast soluble dust proxies such as Ca2+ and nssCa2+ will underestimate this effect but may be better suited to quantify the deposition of chemically active Ca2+ or other soluble dust derived nutrients into the Southern Ocean. The correlation between nssCa2+ and particulate dust is time dependent with high correlations during glacial and low correlation during interglacial times. The low correlation during warm times may be partly caused by changes in the soluble calcium content of dust particles, possibly due to a more acidic atmosphere during interglacials. The ratio of nssCa2+ to dust is dependent on the dust concentration itself. A simple mixing of two dust end members for glacial and interglacial conditions with nssCa2+ to dust ratios of 0.045 and approximately 0.3, respectively, can explain the overall temporal change in the nssCa2+ to dust ratio over time.

scholarly journals A portable Lightweight In Situ Analysis (LISA) box for ice and snow analysis

2021 ◽  
Author(s):  
Helle Astrid Kjær ◽  
Lisa Lolk Hauge ◽  
Marius Simonsen ◽  
Zurine Yoldi ◽  
Iben Koldtoft ◽  
...  
Keyword(s):  
Ice Core ◽  
Flow Analysis ◽  
Snow Accumulation ◽  
Field Conditions ◽  
In Situ Analysis ◽  
Transport Costs ◽  
Water Conductivity ◽  
Annual Layer ◽  
Drilling Site

Abstract. Polar researchers spend enormous costs transporting snow and ice samples to home laboratories for simple analyses in order to constrain annual layer thicknesses and identifying accumulation rates of specific sites. It is well known that depositional noise, incurred from wind drifts, seasonally-biased deposition, melt layers and more, can influence individual snow and firn records and that multiple cores are required to produce statistically robust time series. Thus at many sites core samples are measured in the field for densification, but the annual accumulation and the content of chemical impurities are often represented by just one core to reduce transport costs. We have developed a portable Light weight in Situ Analysis (LISA) box for ice, firn and snow analysis capable of constraining annual layers through the continuous flow analysis of melt water conductivity and peroxide under field conditions. The box can run using a small gasoline-generator and weighs less than 50 kg. The LISA box was tested under field conditions at the deep ice core drilling site EastGRIP in Northern Greenland. Analysis of the top 2 metres of snow from 7 sites in Northern Greenland (Figure 1) allowed the reconstruction of regional snow accumulation patterns for the period 2015–2019.

scholarly journals A first chronology for the East GReenland Ice-core Project (EGRIP) over the Holocene and last glacial termination

2019 ◽  
Author(s):  
Seyedhamidreza Mojtabavi ◽  
Frank Wilhelms ◽  
Eliza Cook ◽  
Siwan Davies ◽  
Giulia Sinnl ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Data Sets ◽  
High Resolution Data ◽  
East Greenland ◽  
The Holocene ◽  
Last Glacial ◽  
Annual Layer ◽  
Geographical Regions ◽  
Core Project

Abstract. This paper provides the first chronology for the deep ice core from the East GReenland Ice-core Project (EGRIP) over the Holocene and late last glacial period. We rely mainly on volcanic events and common patterns of peaks in dielectric profiling (DEP), electrical conductivity measurements (ECM) and tephra records for the synchronization between the EGRIP, NEEM and NGRIP ice cores in Greenland. We transfer the annual-layer-counted Greenland Ice Core Chronology 2005 (GICC05) timescale from the NGRIP core to the EGRIP ice core by means of 373 match points. The NEEM ice core is only used for supporting match-point identification. We name our EGRIP time scale GICC05-EGRIP-1. Over the uppermost 1383.84 m, we establish a depth–age relationship dating back to 14,965 a b2k (years before the year 2000 CE). Tephra horizons provide an independent validation of our match points. In addition, we compare the ratio of annual layer thicknesses between ice cores in-between the match points to assess our results in view of the different ice-flow patterns and accumulation regimes of the different periods and geographical regions. This initial timescale is the basis of interpretation and refinement of the presently derived EGRIP high-resolution data sets of chemical impurities.

scholarly journals On the occurrence of annual layers in Dome Fuji ice core early Holocene ice

2015 ◽  
Vol 11 (9) ◽  
pp. 1127-1137 ◽  
Author(s):  
A. Svensson ◽  
S. Fujita ◽  
M. Bigler ◽  
M. Braun ◽  
R. Dallmayr ◽  
...  
Keyword(s):  
Ice Core ◽  
Flow Analysis ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Early Holocene ◽  
High Temporal Resolution ◽  
High Accumulation ◽  
Data Set ◽  
Antarctic Plateau ◽  
Annual Layer

Abstract. Whereas ice cores from high-accumulation sites in coastal Antarctica clearly demonstrate annual layering, it is debated whether a seasonal signal is also preserved in ice cores from lower-accumulation sites further inland and particularly on the East Antarctic Plateau. In this study, we examine 5 m of early Holocene ice from the Dome Fuji (DF) ice core at a high temporal resolution by continuous flow analysis. The ice was continuously analysed for concentrations of dust, sodium, ammonium, liquid conductivity, and water isotopic composition. Furthermore, a dielectric profiling was performed on the solid ice. In most of the analysed ice, the multi-parameter impurity data set appears to resolve the seasonal variability although the identification of annual layers is not always unambiguous. The study thus provides information on the snow accumulation process in central East Antarctica. A layer counting based on the same principles as those previously applied to the NGRIP (North Greenland Ice core Project) and the Antarctic EPICA (European Project for Ice Coring in Antarctica) Dronning Maud Land (EDML) ice cores leads to a mean annual layer thickness for the DF ice of 3.0 ± 0.3 cm that compares well to existing estimates. The measured DF section is linked to the EDML ice core through a characteristic pattern of three significant acidity peaks that are present in both cores. The corresponding section of the EDML ice core has recently been dated by annual layer counting and the number of years identified independently in the two cores agree within error estimates. We therefore conclude that, to first order, the annual signal is preserved in this section of the DF core. This case study demonstrates the feasibility of determining annually deposited strata on the central East Antarctic Plateau. It also opens the possibility of resolving annual layers in the Eemian section of Antarctic ice cores where the accumulation is estimated to have been greater than in the Holocene.

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