scholarly journals Synchronization of ice core records via atmospheric gases

2007 ◽  
Vol 3 (2) ◽  
pp. 325-330 ◽  
Author(s):  
T. Blunier ◽  
R. Spahni ◽  
J.-M. Barnola ◽  
J. Chappellaz ◽  
L. Loulergue ◽  
...  
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Ice Core ◽  
Ice Cores ◽  
Atmospheric Gases ◽  
Different Types ◽  
Climate Records ◽  
Dronning Maud Land ◽  
Climate Events ◽  
Ice Core Records

Abstract. To interpret new high resolution climate records it becomes more and more important to know about the succession of climate events. Such knowledge is hard to get especially when dealing with different types of climate archives. Even for ice cores a direct synchronization between ice cores from Greenland and Antarctica has not been possible so far due to the lack of time markers occurring in both hemispheres. Fortunately, variations in the time series of global gas records can be used as indirect time markers. Here we discuss in detail the steps that are necessary to synchronize ice cores via global gas records exemplified on the synchronization of the EPICA ice core from Dronning Maud Land to a Greenland record from North GRIP.

scholarly journals Synchronization of ice core records via atmospheric gases

2007 ◽  
Vol 3 (1) ◽  
pp. 365-381 ◽  
Author(s):  
T. Blunier ◽  
R. Spahni ◽  
J.-M. Barnola ◽  
J. Chappellaz ◽  
L. Loulergue ◽  
...  
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Ice Core ◽  
Ice Cores ◽  
Atmospheric Gases ◽  
Different Types ◽  
Climate Records ◽  
Dronning Maud Land ◽  
Climate Events ◽  
Ice Core Records

Abstract. To interpret new high resolution climate records it becomes more and more important to know about the succession of climate events. Such knowledge is hard to get especially when dealing with different types of climate archives. Even for ice cores a direct synchronization between ice cores from Greenland and Antarctica has not been possible so far due to the lack of time markers occurring in both hemispheres. Fortunately, variations in the time series of global gas records can be used as indirect time markers. Here we discuss in detail the steps that are necessary to synchronize ice cores via global gas records exemplified on the synchronization of the EPICA ice core from Dronning Maud Land to a Greenland record from North GRIP.

Tephra in the Greenland Ice cores: Insights into Icelandic volcano-climate impacts

2021 ◽  
Author(s):  
Imogen Gabriel ◽  
Gill Plunkett ◽  
Peter Abbott ◽  
Bergrún Óladóttir ◽  
Joseph McConnell ◽  
...  
Keyword(s):  
High Resolution ◽  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Climate Impacts ◽  
Geochemical Analysis ◽  
Volcanic Events ◽  
Societal Impacts ◽  
The Impact ◽  
Ice Core Records

<p>Volcanic eruptions are considered as one of the primary natural drivers for changes in the global climate system and understanding the impact of past eruptions on the climate is integral to adopt appropriate responses towards future volcanic eruptions.</p><p>The Greenland ice core records are dominated by Icelandic eruptions, with several volcanic systems (Katla, Hekla, Bárðarbunga-Veiðivötn and Grimsvötn) being highly active throughout the Holocene. A notable period of increased Icelandic volcanic activity occurred between 500-1250 AD and coincided with climatic changes in the North Atlantic region which may have facilitated the Viking settlement of Greenland and Iceland. However, a number of these volcanic events are poorly constrained (duration and magnitude). Consequently, the Greenland ice cores offer the opportunity to reliably reconstruct past Icelandic volcanism (duration, magnitude and frequency) due to their high-resolution, the proximity of Iceland to Greenland and subsequent increased likelihood of volcanic fallout deposits (tephra particles and sulphur aerosols) being preserved. However, both the high frequency of eruptions between 500-1250 AD and the geochemical similarity of Iceland’s volcanic centres present challenges in making the required robust geochemical correlations between the source volcano and the ice core records and ultimately reliably assessing the climatic-societal impacts of these eruptions.</p><p>To address this, we use two Greenland ice core records (TUNU2013 and B19) and undertake geochemical analysis on tephra from the volcanic events in the selected time window which have been detected and sampled using novel techniques (insoluble particle peaks and sulphur acidity peaks). Further geochemical analysis of proximal material enables robust correlations to be made between the events in the ice core records and their volcanic centres. The high-resolution of these polar archives provides a precise age for the event and when utilised alongside other proxies (i.e. sulphur aerosols), both the duration and magnitude of these eruptions can be constrained, and the climatic-societal impacts of these eruptions reliably assessed.</p>

scholarly journals High resolution climate reconstructions of recent warming using instrumental and ice core records from coastal Antarctica

MAUSAM ◽  
2021 ◽  
Vol 62 (4) ◽  
pp. 665-672
Author(s):  
MELOTH THAMBAN ◽  
SUSHANT S.NAIK ◽  
C.M. LALURAJ ◽  
R. RAVINDRA
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Southern Oscillation ◽  
Ice Core ◽  
Ice Cores ◽  
Temporal Consistency ◽  
The Past ◽  
Proxy Records ◽  
Dronning Maud Land ◽  
Land Region

In-situ observational record of Antarctic surface temperatures is rather sparse. Proxy based ice core studies are thus critical for reconstructing the past climate change on centennial and decadal time scales. The present study review the available instrumental and proxy records from the Dronning Maud Land region of East Antarctica as well as report recent evidences of Antarctic climate change and its global linkages. The monthly mean air temperature records of the Novolazarevskaya (Novo) station, which is the longest (since 1961) and continuous meteorological record in this region, revealed a significant warming trend at a rate of 0.25 °C / decade. To understand the spatial and temporal consistency of this warming, well-dated ice cores from the coastal Dronning Maud Land region were assessed. All proxy records consistently suggest an enhanced warming up to +0.12 °C / decade. This is further supported by a recent assessment of stable oxygen and hydrogen isotope proxy records from two high resolution ice cores (IND-25/B5 and IND-22/B4) from this region. Among these records, the IND-25/B5 provided ultra-high-resolution data for the past 100 years (1905-2005) and the IND-22/B4 core represented the past ~470 years (1530-2002) of Antarctic change. These ice records provided insights on the influence of solar forcing on Antarctic climate system as well as its linkages with the tropical and mid-latitude climatic modes like the Southern Annular Mode (SAM) and El Niño Southern Oscillation (ENSO). The calculated surface air temperatures using these records showed a warming by 0.06-0.1 °C / decade, with greatly enhanced warming during the past several decades (~0.4 °C / decade). It is confirmed that the coastal areas of Dronning Maud Land are indeed warming and the trend is apparently enhancing in the recent decades.

scholarly journals An improved north–south synchronization of ice core records around the 41 kyr <sup>10</sup>Be peak

2017 ◽  
Vol 13 (3) ◽  
pp. 217-229 ◽  
Author(s):  
Grant M. Raisbeck ◽  
Alexandre Cauquoin ◽  
Jean Jouzel ◽  
Amaelle Landais ◽  
Jean-Robert Petit ◽  
...  
Keyword(s):  
High Resolution ◽  
Spectral Properties ◽  
Ice Core ◽  
Ice Cores ◽  
Published Data ◽  
Geomagnetic Excursion ◽  
Depth Difference ◽  
Order Of Magnitude ◽  
Better Than ◽  
Ice Core Records

Abstract. Using new high-resolution 10Be measurements in the NGRIP, EDML and Vostok ice cores, together with previously published data from EDC, we present an improved synchronization between Greenland and Antarctic ice cores during the Laschamp geomagnetic excursion  ∼  41 kyr ago. We estimate the precision of this synchronization to be ±20 years, an order of magnitude better than previous work. We discuss the implications of this new synchronization for making improved estimates of the depth difference between ice and enclosed gas of the same age (Δdepth), difference between age of ice and enclosed gas at the same depth (Δage) in the EDC and EDML ice cores, spectral properties of the 10Be profiles and phasing between Dansgaard–Oeschger-10 (in NGRIP) and AIM-10 (in EDML and EDC).

scholarly journals Duration of Greenland Stadial 22 and ice-gas Δage from counting of annual layers in Greenland NGRIP ice core

2012 ◽  
Vol 8 (6) ◽  
pp. 1839-1847 ◽  
Author(s):  
P. Vallelonga ◽  
G. Bertagna ◽  
T. Blunier ◽  
H. A. Kjær ◽  
T. J. Popp ◽  
...  
Keyword(s):  
High Resolution ◽  
Ice Core ◽  
Ice Age ◽  
Age Difference ◽  
Glacial Period ◽  
Annual Layer ◽  
Chemical Impurities ◽  
Dronning Maud Land ◽  
Ice Core Records

Abstract. High-resolution measurements of chemical impurities and methane concentrations in Greenland ice core samples from the early glacial period allow the extension of annual-layer counted chronologies and the improvement of gas age-ice age difference (Δage) essential to the synchronization of ice core records. We report high-resolution measurements of a 50 m section of the NorthGRIP ice core and corresponding annual layer thicknesses in order to constrain the duration of the Greenland Stadial 22 (GS-22) between Greenland Interstadials (GIs) 21 and 22, for which inconsistent durations and ages have been reported from Greenland and Antarctic ice core records as well as European speleothems. Depending on the chronology used, GS-22 occurred between approximately 89 (end of GI-22) and 83 kyr b2k (onset of GI-21). From annual layer counting, we find that GS-22 lasted between 2696 and 3092 years and was followed by a GI-21 pre-cursor event lasting between 331 and 369 yr. Our layer-based counting agrees with the duration of stadial 22 as determined from the NALPS speleothem record (3250 ± 526 yr) but not with that of the GICC05modelext chronology (2620 yr) or an alternative chronology based on gas-marker synchronization to EPICA Dronning Maud Land ice core. These results show that GICC05modelext overestimates accumulation and/or underestimates thinning in this early part of the last glacial period. We also revise the possible ranges of NorthGRIP Δdepth (5.49 to 5.85 m) and Δage (498 to 601 yr) at the warming onset of GI-21 as well as the Δage range at the onset of the GI-21 precursor warming (523 to 654 yr), observing that temperature (represented by the δ15N proxy) increases before CH4 concentration by no more than a few decades.

scholarly journals Accumulation variability derived from an ice core from coastal Dronning Maud Land, Antarctica

2004 ◽  
Vol 39 ◽  
pp. 339-345 ◽  
Author(s):  
Marzena Kaczmarska ◽  
Elisabeth Isaksson ◽  
Lars Karlöf ◽  
Jan-Gunnar Winther ◽  
Jack Kohler ◽  
...  
Keyword(s):  
High Resolution ◽  
Accumulation Rate ◽  
Ice Core ◽  
Austral Summer ◽  
Conductivity Measurement ◽  
Ice Cores ◽  
Electrical Conductivity Measurement ◽  
Regional Pattern ◽  
Dronning Maud Land

AbstractA 100 m long ice core was retrieved from the coastal area of Dronning Maud Land (DML), Antarctica, in the 2000/01 austral summer. The core was dated to AD 1737 by identification of volcanic horizons in dielectrical profiling and electrical conductivity measurement records in combination with seasonal layer counting from high-resolution oxygen isotope (δ18O) data. A mean long-term accumulation rate of 0.29 ma–1w.e. was derived from the high-resolution δ18O record as well as accumulation rates during periods in between the identified volcanic horizons. A statistically significant decrease in accumulation was found from about 1920 to the present. A comparison with other coastal ice cores from DML suggests that this is a regional pattern.

scholarly journals Changes in black carbon deposition to Antarctica from two high-resolution ice core records, 1850–2000 AD

2012 ◽  
Vol 12 (9) ◽  
pp. 4107-4115 ◽  
Author(s):  
M. M. Bisiaux ◽  
R. Edwards ◽  
J. R. McConnell ◽  
M. A. J. Curran ◽  
T. D. Van Ommen ◽  
...  
Keyword(s):  
High Resolution ◽  
Black Carbon ◽  
Atmospheric Chemistry ◽  
Ice Core ◽  
Ice Sheet ◽  
Ice Cores ◽  
Fire Regimes ◽  
Antarctic Ice Sheet ◽  
Continental Hydrology ◽  
Ice Core Records

Abstract. Refractory black carbon aerosols (rBC) emitted by biomass burning (fires) and fossil fuel combustion, affect global climate and atmospheric chemistry. In the Southern Hemisphere (SH), rBC is transported in the atmosphere from low- and mid-latitudes to Antarctica and deposited to the polar ice sheet preserving a history of emissions and atmospheric transport. Here, we present two high-resolution Antarctic rBC ice core records drilled from the West Antarctic Ice Sheet divide and Law Dome on the periphery of the East Antarctic ice sheet. Separated by ~3500 km, the records span calendar years 1850–2001 and reflect the rBC distribution over the Indian and Pacific ocean sectors of the Southern Ocean. Concentrations of rBC in the ice cores displayed significant variability at annual to decadal time scales, notably in ENSO-QBO and AAO frequency bands. The delay observed between rBC and ENSO variability suggested that ENSO does not directly affect rBC transport, but rather continental hydrology, subsequent fire regimes, and aerosol emissions. From 1850 to 1950, the two ice core records were uncorrelated but were highly correlated from 1950 to 2002 (cross-correlation coefficient at annual resolution: r = 0.54, p < 0.01) due to a common decrease in rBC variability. The decrease in ice-core rBC from the 1950s to late 1980s displays similarities with inventories of SH rBC grass fires and biofuel emissions, which show reduced emission estimates over that period.

Reconstructing an Interdecadal Pacific Oscillation Index from a Pacific Basin–Wide Collection of Ice Core Records

2021 ◽  
Vol 34 (10) ◽  
pp. 3839-3852
Author(s):  
Stacy E. Porter ◽  
Ellen Mosley-Thompson ◽  
Lonnie G. Thompson ◽  
Aaron B. Wilson
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Tropical Pacific ◽  
Ice Age ◽  
Pacific Basin ◽  
Interdecadal Pacific Oscillation ◽  
The Pacific ◽  
Instrumental Period ◽  
The Tropical Pacific ◽  
Ice Core Records

AbstractUsing an assemblage of four ice cores collected around the Pacific basin, one of the first basinwide histories of Pacific climate variability has been created. This ice core–derived index of the interdecadal Pacific oscillation (IPO) incorporates ice core records from South America, the Himalayas, the Antarctic Peninsula, and northwestern North America. The reconstructed IPO is annually resolved and dates to 1450 CE. The IPO index compares well with observations during the instrumental period and with paleo-proxy assimilated datasets throughout the entire record, which indicates a robust and temporally stationary IPO signal for the last ~550 years. Paleoclimate reconstructions from the tropical Pacific region vary greatly during the Little Ice Age (LIA), although the reconstructed IPO index in this study suggests that the LIA was primarily defined by a weak, negative IPO phase and hence more La Niña–like conditions. Although the mean state of the tropical Pacific Ocean during the LIA remains uncertain, the reconstructed IPO reveals some interesting dynamical relationships with the intertropical convergence zone (ITCZ). In the current warm period, a positive (negative) IPO coincides with an expansion (contraction) of the seasonal latitudinal range of the ITCZ. This relationship is not stationary, however, and is virtually absent throughout the LIA, suggesting that external forcing, such as that from volcanoes and/or reduced solar irradiance, could be driving either the ITCZ shifts or the climate dominating the ice core sites used in the IPO reconstruction.

scholarly journals Towards a quasi-complete reconstruction of past atmospheric aerosol load and composition (organic and inorganic) over Europe since 1920 inferred from Alpine ice cores

2013 ◽  
Vol 9 (4) ◽  
pp. 1403-1416 ◽  
Author(s):  
S. Preunkert ◽  
M. Legrand
Keyword(s):  
World War Ii ◽  
Organic Carbon ◽  
Atmospheric Aerosol ◽  
Ice Core ◽  
Ice Cores ◽  
Organic Aerosol ◽  
Water Soluble ◽  
Climate Forcing ◽  
World War ◽  
Ice Core Records

Abstract. Seasonally resolved chemical ice core records available from the Col du Dôme glacier (4250 m elevation, French Alps), are here used to reconstruct past aerosol load and composition of the free European troposphere from before World War II to present. Available ice core records include inorganic (Na+, Ca2+, NH4+, Cl−, NO3−, and SO42−) and organic (carboxylates, HCHO, humic-like substances, dissolved organic carbon, water-insoluble organic carbon, and black carbon) compounds and fractions that permit reconstructing the key aerosol components and their changes over the past. It is shown that the atmospheric load of submicron aerosol has been increased by a factor of 3 from the 1921–1951 to 1971–1988 years, mainly as a result of a large increase of sulfate (a factor of 5), ammonium and water-soluble organic aerosol (a factor of 3). Thus, not only growing anthropogenic emissions of sulfur dioxide and ammonia have caused the enhancement of the atmospheric aerosol load but also biogenic emissions producing water-soluble organic aerosol. This unexpected change of biospheric source of organic aerosol after 1950 needs to be considered and further investigated in scenarios dealing with climate forcing by atmospheric aerosol.

scholarly journals Detecting dynamical anomalies in time series from different palaeoclimate proxy archives using windowed recurrence network analysis

2019 ◽  
Author(s):  
Jaqueline Lekscha ◽  
Reik V. Donner
Keyword(s):  
Time Series ◽  
Network Analysis ◽  
Nonlinear Filtering ◽  
Ice Cores ◽  
Second Step ◽  
Different Types ◽  
Output Time ◽  
Input Time ◽  
Past Climate Variability ◽  
Input Time Series

Abstract. Analysing palaeoclimate proxy time series using windowed recurrence network analysis (wRNA) has been shown to provide valuable information on past climate variability. In turn, it has also been found that the robustness of the obtained results differs among proxies from different palaeoclimate archives. To systematically test the suitability of wRNA for studying different types of palaeoclimate proxy time series, we use the framework of forward proxy modelling. For this, we create artificial input time series with different properties and, in a first step, compare the time series properties of the input and the model output time series. In a second step, we compare the areawise significant anomalies detected using wRNA. For proxies from tree and lake archives, we find that significant anomalies present in the input time series are sometimes missed in the input time series after the nonlinear filtering by the corresponding models. For proxies from speleothems, we observe falsely identified significant anomalies that are not present in the input time series. Finally, for proxies from ice cores, the wRNA results show the best correspondence with those for the input data. Our results contribute to improve the interpretation of windowed recurrence network analysis results obtained from real-world palaeoclimate time series.

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