scholarly journals A 21 000-year record of fluorescent organic matter markers in the WAIS Divide ice core

2017 ◽  
Vol 13 (5) ◽  
pp. 533-544 ◽  
Author(s):  
Juliana D'Andrilli ◽  
Christine M. Foreman ◽  
Michael Sigl ◽  
John C. Priscu ◽  
Joseph R. McConnell
Keyword(s):  
Fluorescence Spectroscopy ◽  
Ice Core ◽  
Temporal Trends ◽  
Three Dimensional ◽  
Chemical Species ◽  
Chemical Components ◽  
Last Deglaciation ◽  
Sea Ice Extent ◽  
West Antarctic ◽  
Carbon Productivity

Abstract. Englacial ice contains a significant reservoir of organic material (OM), preserving a chronological record of materials from Earth's past. Here, we investigate if OM composition surveys in ice core research can provide paleoecological information on the dynamic nature of our Earth through time. Temporal trends in OM composition from the early Holocene extending back to the Last Glacial Maximum (LGM) of the West Antarctic Ice Sheet Divide (WD) ice core were measured by fluorescence spectroscopy. Multivariate parallel factor (PARAFAC) analysis is widely used to isolate the chemical components that best describe the observed variation across three-dimensional fluorescence spectroscopy (excitation–emission matrices; EEMs) assays. Fluorescent OM markers identified by PARAFAC modeling of the EEMs from the LGM (27.0–18.0 kyr BP; before present 1950) through the last deglaciation (LD; 18.0–11.5 kyr BP), to the mid-Holocene (11.5–6.0 kyr BP) provided evidence of different types of fluorescent OM composition and origin in the WD ice core over 21.0 kyr. Low excitation–emission wavelength fluorescent PARAFAC component one (C1), associated with chemical species similar to simple lignin phenols was the greatest contributor throughout the ice core, suggesting a strong signature of terrestrial OM in all climate periods. The component two (C2) OM marker, encompassed distinct variability in the ice core describing chemical species similar to tannin- and phenylalanine-like material. Component three (C3), associated with humic-like terrestrial material further resistant to biodegradation, was only characteristic of the Holocene, suggesting that more complex organic polymers such as lignins or tannins may be an ecological marker of warmer climates. We suggest that fluorescent OM markers observed during the LGM were the result of greater continental dust loading of lignin precursor (monolignol) material in a drier climate, with lower marine influences when sea ice extent was higher and continents had more expansive tundra cover. As the climate warmed, the record of OM markers in the WD ice core changed, reflecting shifts in carbon productivity as a result of global ecosystem response.

scholarly journals A 21,000 year record of organic matter quality in the WAIS Divide ice core

2016 ◽  
Author(s):  
Juliana D'Andrilli ◽  
Christine M. Foreman ◽  
Michael Sigl ◽  
John C. Priscu ◽  
Joseph R. McConnell
Keyword(s):  
Environmental Changes ◽  
Ice Core ◽  
Temporal Trends ◽  
Chemical Species ◽  
Last Deglaciation ◽  
Sea Ice Extent ◽  
Organic Matter Quality ◽  
Fluorescent Intensity ◽  
West Antarctic ◽  
Carbon Productivity

Abstract. Englacial ice contains a significant reservoir of organic material (OM), preserving a chronological record of materials from Earth's past. Here, we investigate if OM quality surveys in ice core research can provide paleoecological information on the dynamic nature of our Earth through time. Temporal trends in OM quality from the early Holocene extending back to the Last Glacial Maximum (LGM) of the West Antarctic Ice Sheet Divide (WD) ice core were measured by fluorescence spectroscopy. Fluorescent intensity fluctuations and PARAFAC modelling of fluorescent OM from the LGM (27.0–18,0 kyrs BP; before present 1950), through the last deglaciation (LD; 18.0–11.5 kyrs BP), to the early to mid-Holocene (11.5–6.0 kyrs BP) provided evidence of different types of OM chemical species in the WD ice core over 21.0 kyrs. Two proteinaceous PARAFAC components (C1 and C2) were characteristic of fluorescent OM prevailing in all climate periods, suggesting a strong signature of labile microbial OM. A humic-like component (C3), characteristic of terrestrial and marine OM fluorescence, was only observed during the Holocene, suggesting that recalcitrant OM may be an ecological marker of warmer climates. Fluctuations in WD ice core OM fluorescence over 21.0 kyrs BP may be driven by environmental changes at the source, and potentially its interaction with the atmosphere. We suggest that fluorescent OM signatures observed during the LGM were the result of greater continental dust loading of microbially derived proteinaceous material in a drier climate, with lower marine influences when sea ice extent was higher, and continents had more expansive tundra cover. As the climate warmed, the OM quality record in the WD ice core changed, reflecting shifts in carbon productivity as a result of global ecosystem response.

scholarly journals The Amundsen Sea Low: Variability, Change, and Impact on Antarctic Climate

2016 ◽  
Vol 97 (1) ◽  
pp. 111-121 ◽  
Author(s):  
M. N. Raphael ◽  
G. J. Marshall ◽  
J. Turner ◽  
R. L. Fogt ◽  
D. Schneider ◽  
...  
Keyword(s):  
Sea Ice ◽  
Climate Model ◽  
Ross Sea ◽  
Ice Core ◽  
Meridional Wind ◽  
West Antarctica ◽  
Sea Ice Extent ◽  
Amundsen Sea ◽  
West Antarctic ◽  
Climate Model Simulations

Abstract The Amundsen Sea low (ASL) is a climatological low pressure center that exerts considerable influence on the climate of West Antarctica. Its potential to explain important recent changes in Antarctic climate, for example, in temperature and sea ice extent, means that it has become the focus of an increasing number of studies. Here, the authors summarize the current understanding of the ASL, using reanalysis datasets to analyze recent variability and trends, as well as ice-core chemistry and climate model projections, to examine past and future changes in the ASL, respectively. The ASL has deepened in recent decades, affecting the climate through its influence on the regional meridional wind field, which controls the advection of moisture and heat into the continent. Deepening of the ASL in spring is consistent with observed West Antarctic warming and greater sea ice extent in the Ross Sea. Climate model simulations for recent decades indicate that this deepening is mediated by tropical variability while climate model projections through the twenty-first century suggest that the ASL will deepen in some seasons in response to greenhouse gas concentration increases.

scholarly journals An emerging technique: multi-ice-core multi-parameter correlations with Antarctic sea-ice extent

2011 ◽  
Vol 52 (57) ◽  
pp. 347-354 ◽  
Author(s):  
Sharon B. Sneed ◽  
Paul A. Mayewski ◽  
Daniel A. Dixon
Keyword(s):  
Sea Ice ◽  
Ice Core ◽  
Chemical Species ◽  
Ice Cores ◽  
Initial Step ◽  
Single Species ◽  
Parameter Study ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
Siple Dome

AbstractUsing results stemming from the International Trans-Antarctic Scientific Expedition (ITASE) ice-core array plus data from ice cores from the South Pole and Siple Dome we investigate the use of sodium (Na+), non-sea-salt sulfate (nssSO42–) and methylsulfonate (MS–) as proxies for Antarctic sea-ice extent (SIE). Maximum and mean annual chemistry concentrations for these three species correlate significantly with maximum, mean and minimum annual SIE, offering more information and clarification than single ice-core and single species approaches. Significant correlations greater than 90% exist between Na+ and maximum SIE; nssSO42– with minimum and mean SIE; and MS– with mean SIE. Correlations with SIE within large geographic regions are in the same direction for all ice-core sites for Na+ and nssSO42– but not MS–. All ice cores display an SIE correlation with nssSO42– and MS–, but not all correlate with Na+. This multi-core multi-parameter study provides the initial step in determining which chemical species can be used reliably and in which regions as a building block for embedding other ice-core records. Once established, the resulting temporal and spatial matrix can be used to relate ice extents, atmospheric patterns, biological productivity and site conditions.

scholarly journals Sea ice and pollution-modulated changes in Greenland ice core methanesulfonate and bromine

2017 ◽  
Vol 13 (1) ◽  
pp. 39-59 ◽  
Author(s):  
Olivia J. Maselli ◽  
Nathan J. Chellman ◽  
Mackenzie Grieman ◽  
Lawrence Layman ◽  
Joseph R. McConnell ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Core ◽  
Chemical Species ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Arctic Sea Ice ◽  
Sea Ice Extent ◽  
Back Trajectories ◽  
Future Evolution ◽  
Source Regions

Abstract. Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved in ice cores have both been proposed as indicators of past sea ice conditions. In this study, two ice cores from central and north-eastern Greenland were analysed at sub-annual resolution for MSA (CH3SO3H) and bromine, covering the time period 1750–2010. We examine correlations between ice core MSA and the HadISST1 ICE sea ice dataset and consult back trajectories to infer the likely source regions. A strong correlation between the low-frequency MSA and bromine records during pre-industrial times indicates that both chemical species are likely linked to processes occurring on or near sea ice in the same source regions. The positive correlation between ice core MSA and bromine persists until the mid-20th century, when the acidity of Greenland ice begins to increase markedly due to increased fossil fuel emissions. After that time, MSA levels decrease as a result of declining sea ice extent but bromine levels increase. We consider several possible explanations and ultimately suggest that increased acidity, specifically nitric acid, of snow on sea ice stimulates the release of reactive Br from sea ice, resulting in increased transport and deposition on the Greenland ice sheet.

scholarly journals Seasonal characteristics of the major ions in the high-accumulation Dome Summit South ice core, Law Dome, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 385-390 ◽  
Author(s):  
Mark A.J. Curran ◽  
Tas D. Van Ommen ◽  
Vin Morgan
Keyword(s):  
Major Ions ◽  
Seasonal Pattern ◽  
Ice Core ◽  
Chemical Species ◽  
Sea Salt ◽  
Seasonal Cycles ◽  
High Accumulation ◽  
Sea Ice Extent ◽  
Seasonal Characteristics ◽  
Polar Snow

Seasonal cycles of the chemical species Na+, Κ+ , Mg2+, Ca2+, CH3SO3 (MSA) Cl− NO3 − and NO3 − in the Dome Summit South (DSS) ice core from Law Dome were measured for a number of epochs (AD 1809-15, 1821-31 1980-92) span-nine a total of 28 years. These preliminary trace-chemical patterns show that the DSS site is mainly affected by marine air. The main features found in the seasonal pattern of sea-salt concentrations (e.g. Na+, Cl− and Mg2+) were a winter peak and a summer minimum. The variations in sea salts are believed to reflect aerosol production and transport due to the level of storminess, and are less affected by sea-ice extent. The seasonal cycles of marine biogenic compounds, non-sea-salt SO4 2- and MSA are in good agreement. They show a characteristic summer maximum arid a winter minimum, due to variations in biological activity. While the main sources of nitrate in polar snow remain unclear, the seasonal signal, including sub-seasonal structure, at DSS resembles that found m the atmosphere at coastal Antarctic sites. However, the timing of the nitrate maximum is different in the ice-core record compared with the aerosol records. Overall, the results indicate that the DSS core, with sub-seasonal resolution, contains a sensitive record for investigating climate variability.

scholarly journals Constraining past accumulation in the central Pine Island Glacier basin, West Antarctica, using radio-echo sounding

2014 ◽  
Vol 60 (221) ◽  
pp. 553-562 ◽  
Author(s):  
Nanna B. Karlsson ◽  
Robert G. Bingham ◽  
David M. Rippin ◽  
Richard C.A. Hindmarsh ◽  
Hugh F.J. Corr ◽  
...  
Keyword(s):  
Ice Core ◽  
Three Dimensional ◽  
Dynamical Instability ◽  
West Antarctica ◽  
Last Glacial Period ◽  
Accumulation Pattern ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
Radio Echo Sounding ◽  
Echo Sounding

AbstractThe potential for future dynamical instability of Pine Island Glacier, West Antarctica, has been addressed in a number of studies, but information on its past remains limited. In this study we use airborne radio-echo sounding (RES) data acquired over Pine Island Glacier to investigate past variations in accumulation pattern. In the dataset a distinctive pattern of layers was identified in the central part of the glacier basin. We use these layers as chronological identifiers in order to construct elevation maps of the internal stratigraphy. The observed internal layer stratigraphy is then compared to calculated stratigraphy from a three-dimensional ice-flow model that has been forced with different accumulation scenarios. The model results indicate that the accumulation pattern is likely to have changed at least twice since the deposition of the deepest identified layer. Additional RES data linked to the Byrd ice core provide an approximate timescale. This timescale suggests that the layers were deposited at the beginning of or during the Holocene period. Thus the widespread changes occurring in the coastal extent of the West Antarctic ice sheet at the end of the last glacial period could have been accompanied by changes in accumulation pattern.

scholarly journals Sensitivity of chemical species to climatic changes in the last 45 kyr as revealed by high-resolution Dome C (East Antarctica) ice-core analysis

2004 ◽  
Vol 39 ◽  
pp. 457-466 ◽  
Author(s):  
Roberto Udisti ◽  
Silvia Becagli ◽  
Silvia Benassai ◽  
Martine De Angelis ◽  
Margareta E. Hansson ◽  
...  
Keyword(s):  
High Resolution ◽  
Environmental Changes ◽  
Accumulation Rate ◽  
Ice Core ◽  
Chemical Species ◽  
Climatic Changes ◽  
Snow Accumulation ◽  
Last Deglaciation ◽  
Temperature Trends ◽  
Chemical Profiles

AbstractTo assess the cause/effect relationship between climatic and environmental changes, we report high-resolution chemical profiles of the Dome C ice core (788m, 45 kyr), drilled in the framework of the European Project for Ice Coring in Antarctica (EPICA). Snow-concentration and depositional-flux changes during the last deglaciation were compared with climatic changes, derived by δD profile. Concentration and temperature profiles showed an anticorrelation, driven by changes in source intensity and transport efficiency of the atmospheric aerosol and by snow accumulation-rate variations. The flux calculation allowed correction for accumulation rate. While sulphate and ammonium fluxes are quite constant, Na+, Mg2+ and Ca2+ underwent the greatest changes, showing fluxes respectively about two, three and six times lower in the Holocene than in the Last Glacial Maximum. Chloride, nitrate and methanesulphonic acid (MSA) also exhibited large changes, but their persistence depends on depositional and post-depositional effects. The comparison between concentrations and δD profiles revealed leads and lags between chemical and temperature trends: Ca2+ and nitrate preceded by about 300 years the δD increase at the deglaciation onset, while MSA showed a 400 year delay. Generally, all components reached low Holocene values in the first deglaciation step (18.0–14.0 kyr BP), but Na+, Mg2+ and nitrate show changes during the Antarctic Cold Reversal (14.0– 12.5 kyr BP).

scholarly journals A 200 year sulfate record from 16 Antarctic ice cores and associations with Southern Ocean sea-ice extent

2005 ◽  
Vol 41 ◽  
pp. 155-166 ◽  
Author(s):  
Daniel Dixon ◽  
Paul A. Mayewski ◽  
Susan Kaspari ◽  
Karl Kreutz ◽  
Gordon Hamilton ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ross Sea ◽  
Ice Core ◽  
Ice Cores ◽  
South Pole ◽  
West Antarctica ◽  
The South ◽  
Sea Ice Extent ◽  
West Antarctic ◽  
Low Latitudes

AbstractChemistry data from 16, 50–115m deep, sub-annually dated ice cores are used to investigate spatial and temporal concentration variability of sea-salt (ss) SO42– and excess (xs) SO42– over West Antarctica and the South Pole for the last 200 years. Low-elevation ice-core sites in western West Antarctica contain higher concentrations of SO42– as a result of cyclogenesis over the Ross Ice Shelf and proximity to the Ross Sea Polynya. Linear correlation analysis of 15 West Antarctic ice-core SO42– time series demonstrates that at several sites concentrations of ssSO42– are higher when sea-ice extent (SIE) is greater, and the inverse for xsSO42–. Concentrations of xsSO42– from the South Pole site (East Antarctica) are associated with SIE from the Weddell region, and West Antarctic xsSO42– concentrations are associated with SIE from the Bellingshausen–Amundsen–Ross region. The only notable rise of the last 200 years in xsSO42–, around 1940, is not related to SIE fluctuations and is most likely a result of increased xsSO42– production in the mid–low latitudes and/or an increase in transport efficiency from the mid–low latitudes to central West Antarctica. These high-resolution records show that the source types and source areas of ssSO42– and xsSO42– delivered to eastern and western West Antarctica and the South Pole differ from site to site but can best be resolved using records from spatial ice-core arrays such as the International Trans-Antarctic Scientific Expedition (ITASE).

scholarly journals Seasonal characteristics of the major ions in the high-accumulation Dome Summit South ice core, Law Dome, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 385-390 ◽  
Author(s):  
Mark A.J. Curran ◽  
Tas D. Van Ommen ◽  
Vin Morgan
Keyword(s):  
Major Ions ◽  
Seasonal Pattern ◽  
Ice Core ◽  
Chemical Species ◽  
Sea Salt ◽  
Seasonal Cycles ◽  
High Accumulation ◽  
Sea Ice Extent ◽  
Seasonal Characteristics ◽  
Polar Snow

Seasonal cycles of the chemical species Na+, Κ+ , Mg2+, Ca2+, CH3SO3 (MSA) Cl− NO3 − and NO3 − in the Dome Summit South (DSS) ice core from Law Dome were measured for a number of epochs (AD 1809-15, 1821-31 1980-92) span-nine a total of 28 years. These preliminary trace-chemical patterns show that the DSS site is mainly affected by marine air. The main features found in the seasonal pattern of sea-salt concentrations (e.g. Na+, Cl− and Mg2+) were a winter peak and a summer minimum. The variations in sea salts are believed to reflect aerosol production and transport due to the level of storminess, and are less affected by sea-ice extent. The seasonal cycles of marine biogenic compounds, non-sea-salt SO4 2- and MSA are in good agreement. They show a characteristic summer maximum arid a winter minimum, due to variations in biological activity. While the main sources of nitrate in polar snow remain unclear, the seasonal signal, including sub-seasonal structure, at DSS resembles that found m the atmosphere at coastal Antarctic sites. However, the timing of the nitrate maximum is different in the ice-core record compared with the aerosol records. Overall, the results indicate that the DSS core, with sub-seasonal resolution, contains a sensitive record for investigating climate variability.

scholarly journals An 83 000-year-old ice core from Roosevelt Island, Ross Sea, Antarctica

2020 ◽  
Vol 16 (5) ◽  
pp. 1691-1713 ◽  
Author(s):  
James E. Lee ◽  
Edward J. Brook ◽  
Nancy A. N. Bertler ◽  
Christo Buizert ◽  
Troy Baisden ◽  
...  
Keyword(s):  
Ross Sea ◽  
Ice Core ◽  
Ice Cores ◽  
Ice Age ◽  
Age Difference ◽  
Last Deglaciation ◽  
Ice Streams ◽  
West Antarctic Ice Sheet ◽  
Annual Layer ◽  
West Antarctic

Abstract. In 2013 an ice core was recovered from Roosevelt Island, an ice dome between two submarine troughs carved by paleo-ice-streams in the Ross Sea, Antarctica. The ice core is part of the Roosevelt Island Climate Evolution (RICE) project and provides new information about the past configuration of the West Antarctic Ice Sheet (WAIS) and its retreat during the last deglaciation. In this work we present the RICE17 chronology, which establishes the depth–age relationship for the top 754 m of the 763 m core. RICE17 is a composite chronology combining annual layer interpretations for 0–343 m (Winstrup et al., 2019) with new estimates for gas and ice ages based on synchronization of CH4 and δ18Oatm records to corresponding records from the WAIS Divide ice core and by modeling of the gas age–ice age difference. Novel aspects of this work include the following: (1) an automated algorithm for multiproxy stratigraphic synchronization of high-resolution gas records; (2) synchronization using centennial-scale variations in methane for pre-anthropogenic time periods (60–720 m, 1971 CE to 30 ka), a strategy applicable for future ice cores; and (3) the observation of a continuous climate record back to ∼65 ka providing evidence that the Roosevelt Island Ice Dome was a constant feature throughout the last glacial period.

Sign in / Sign up

Export Citation Format

Share Document