Stable Isotopes and their Relationship to Temperature as Recorded in Low-Latitude Ice Cores

2001 ◽  
pp. 99-119
Keyword(s):  
Stable Isotopes ◽  
Ice Cores ◽  
Low Latitude

scholarly journals Towards radiocarbon dating of ice cores

2009 ◽  
Vol 55 (194) ◽  
pp. 985-996 ◽  
Author(s):  
M. Sigl ◽  
T.M. Jenk ◽  
T. Kellerhals ◽  
S. Szidat ◽  
H.W. Gäggeler ◽  
...  
Keyword(s):  
Aerosol Particles ◽  
Ice Core ◽  
Ice Cores ◽  
Swiss Alps ◽  
Carbonaceous Aerosol ◽  
Polar Ice ◽  
Low Latitude ◽  
Bolivian Andes ◽  
Glacier Ice ◽  
Dating Method

AbstractA recently developed dating method for glacier ice, based on the analysis of radiocarbon in carbonaceous aerosol particles, is thoroughly investigated. We discuss the potential of this method to achieve a reliable dating using examples from a mid- and a low-latitude ice core. Two series of samples from Colle Gnifetti (4450 m a.s.l., Swiss Alps) and Nevado Illimani (6300 m a.s.l., Bolivian Andes) demonstrate that the 14C ages deduced from the water-insoluble organic carbon fraction represent the age of the ice. Sample sizes ranged between 7 and 100 μg carbon. For validation we compare our results with those from independent dating. This new method is thought to have major implications for dating non-polar ice cores in the future, as it provides complementary age information for time periods not accessible with common dating techniques.

scholarly journals NAO signal recorded in the stable isotopes of Greenland ice cores

2003 ◽  
Vol 30 (7) ◽  
Author(s):  
B. M. Vinther ◽  
S. J. Johnsen ◽  
K. K. Andersen ◽  
H. B. Clausen ◽  
A. W. Hansen
Keyword(s):  
Stable Isotopes ◽  
Ice Cores

scholarly journals Using characteristic times to assess whether stable isotopes in polar snow can be reversibly deposited

2002 ◽  
Vol 35 ◽  
pp. 118-124 ◽  
Author(s):  
Edwin D. Waddington ◽  
Eric J. Steig ◽  
Thomas A. Neumann
Keyword(s):  
Boundary Layer ◽  
Stable Isotopes ◽  
Water Vapor ◽  
Accumulation Rate ◽  
Ice Cores ◽  
Isotopic Signature ◽  
Snow Surface ◽  
Atmospheric Water ◽  
Resistor Network ◽  
Polar Snow

AbstractStable isotopes in ice cores are used as a proxy for the temperature at the time of snow formation. Where net accumulation rate is relatively high, snow is buried quickly and initial isotopic values are preserved. However, in low-accumulation areas, snow is exposed to lengthy vapor exchange with the atmosphere. the original isotopic signature of this snow may be modified by equilibration with atmospheric water vapor in the boundary layer over the snow surface in summer. We estimate the characteristic times for equilibration by using an electrical resistor network analogue. Warm, windy summers and low accumulation rate enhance equilibration. Although equilibration of the complete snowpack is unlikely, significant post-depositional change may occur in some Antarctic environments.

scholarly journals Air pollutants in Xinjiang during the COVID-19 pandemic and glaciochemical records of a Tien-Shan glacier

2021 ◽  
Author(s):  
Feiteng Wang ◽  
Xin Zhang ◽  
Fanglong Wang ◽  
Mengyuan Song ◽  
Zhongqin Li ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Organic Carbon ◽  
Tree Rings ◽  
Air Pollutants ◽  
Local Governments ◽  
Ice Cores ◽  
Tien Shan ◽  
Autonomous Region ◽  
Soluble Ions ◽  
The World

Abstract. The outbreak of COVID-19 unprecedently impacts the world in many aspects. Air pollutants have been largely reduced in cities worldwide, as reported by numerous studies. We investigated the daily concentrations of SO2, NO2, CO and PM2.5 monitored across the Xinjiang Uygur Autonomous Region (Xinjiang), China, from 2019 through 2020. The variation in NO2 showed responding dips when the local governments imposed mobility restriction measures, while SO2, CO and PM2.5 did not consistently correspond to NO2. This difference indicates that the restriction measures targeted traffic majorly. Sampling from two snow pits separately dug in 2019 and 2020 in Urumqi No.1 (UG1), we analysed water-stable isotopes, soluble ions, black and organic carbon (BC and OC). BC and OC show no differences in the snow-pit profiles dated from 2018 to 2020. The concentrations of human activity induced soluble ions (K+, Cl−, SO42− and NO3−) in the snow shrank to 20 %–30% in 2020 of their respective concentrations in 2019, while they increased 2–3.5-fold in 2019 from before 2018. We suggest that the pandemic has already left marks in the cryosphere and outlook that more evidence would be exposed in ice cores, tree rings, and other archives in the future.

scholarly journals Antarctic surface temperature and elevation during the Last Glacial Maximum

Science ◽  
2021 ◽  
Vol 372 (6546) ◽  
pp. 1097-1101
Author(s):  
Christo Buizert ◽  
T. J. Fudge ◽  
William H. G. Roberts ◽  
Eric J. Steig ◽  
Sam Sherriff-Tadano ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Last Glacial Maximum ◽  
Climate Models ◽  
Global Climate ◽  
Ice Cores ◽  
Temperature Inversion ◽  
Glacial Maximum ◽  
Global Climate Models ◽  
Surface Cooling ◽  
Last Glacial

Water-stable isotopes in polar ice cores are a widely used temperature proxy in paleoclimate reconstruction, yet calibration remains challenging in East Antarctica. Here, we reconstruct the magnitude and spatial pattern of Last Glacial Maximum surface cooling in Antarctica using borehole thermometry and firn properties in seven ice cores. West Antarctic sites cooled ~10°C relative to the preindustrial period. East Antarctic sites show a range from ~4° to ~7°C cooling, which is consistent with the results of global climate models when the effects of topographic changes indicated with ice core air-content data are included, but less than those indicated with the use of water-stable isotopes calibrated against modern spatial gradients. An altered Antarctic temperature inversion during the glacial reconciles our estimates with water-isotope observations.

scholarly journals Atmospheric variability and precipitation in the Ross Sea region, Antarctica

2021 ◽  
Author(s):  
◽  
Lana Cohen
Keyword(s):  
Stable Isotopes ◽  
Isotopic Composition ◽  
Ross Sea ◽  
Isotope Composition ◽  
Ice Cores ◽  
Atmospheric Variability ◽  
Ice Shelf ◽  
Ross Ice Shelf ◽  
The Pacific ◽  
Climate Proxies

<p>Understanding how atmospheric variability in the Pacific sector of Antarctica drives precipitation is essential for understanding current and past climate changes on the West Antarctic Ice Sheet and the Ross Ice Shelf. Precipitation plays a key role in the Antarctic climate system (via mass balance of ice sheets) and is necessary for understanding past climates (via snow and ice proxies). However precipitation is difficult to measure and model and its variability in these regions is still not well understood. This thesis compiles three separate but inter-related studies which provide further understanding of the atmospheric variability of the Ross Sea region and its role in driving precipitation.   Synoptic classifications over the Southern Ocean in the Pacific sector of Antarctica (50°S–Antarctic coast, 150°E–90°W) are derived from NCEP reanalysis data (1979–2011), producing a set of six synoptic types for the region. These six types describe the atmospheric variability of the Ross and Amundsen Seas region for the past 33 years and show how hemispheric scale circulation patterns such as the El Niño-Southern Oscillation and the Southern Annular Mode are reflected in local precipitation and temperature on the Ross Ice Shelf. The synoptic types also provide understanding of how different source regions and transport pathways can influence precipitation on the Ross Ice Shelf, which is important for the interpretation of climate proxies.   Because of the sparseness of in-situ meteorological measurements in Antarctica, many studies (including the two described above) rely on atmospheric reanalyses data. However, assessments of reanalyses precipitation have only been done on annual and longer timescales. An assessment of the ERA-Interim and NCEP-2 reanalyses precipitation data on synoptic timescales is developed using statistical, event-based analysis of snow accumulation data from automatic weather stations around the Ross Ice Shelf. The results show that there are important differences between the two reanalyses products and that ERA-Interim represents precipitation better than NCEP-2 for this region.   Stable isotopes in snow (δ¹⁸O and δD) are widely used as temperature proxies, but are also influenced by moisture history, source region conditions, and cloud micro-physical processes. Further understanding of the relative importance of these other factors is provided by modeling the isotopic composition of snow at Roosevelt Island, an ice core site on the Ross Ice Shelf. A Rayleigh fractionation model is used to determine isotope composition on sub-storm (hourly) timescales, and the results are compared to measured isotope composition. The model is able to reproduce the significant variability of measured isotopes and shows the importance of air-mass mixing and moisture trajectories on the isotopic composition of snow at Roosevelt Island.   Together, these studies show how synoptic variability influences precipitation on the Ross Ice Shelf and at Roosevelt Island in particular, and they provide a basis for interpreting stable isotopes and other precipitation-based climate proxies in ice cores from the Roosevelt Island site.</p>

Sign in / Sign up

Export Citation Format

Share Document