Regional climate signal vs. local noise
- In low-accumulation regions, the reliability of delta O-18-derived temperature signals from ice cores within the Holocene is unclear, primarily due to the small climate changes relative to the intrinsic noise of the isotopic signal. In order to learn about the representativity of single ice cores and to optimise future ice-core-based climate reconstructions, we studied the stable-water isotope composition of firn at Kohnen Station, Dronning Maud Land, Antarctica. Analysing delta O-18 in two 50m long snow trenches allowed us to create an unprecedented, two-dimensional image characterising the isotopic variations from the centimetre to the 100-metre scale. Our results show seasonal layering of the isotopic composition but also high horizontal isotopic variability caused by local stratigraphic noise. Based on the horizontal and vertical structure of the isotopic variations, we derive a statistical noise model which successfully explains the trench data. The model further allows one to determine an upper bound for the reliability ofIn low-accumulation regions, the reliability of delta O-18-derived temperature signals from ice cores within the Holocene is unclear, primarily due to the small climate changes relative to the intrinsic noise of the isotopic signal. In order to learn about the representativity of single ice cores and to optimise future ice-core-based climate reconstructions, we studied the stable-water isotope composition of firn at Kohnen Station, Dronning Maud Land, Antarctica. Analysing delta O-18 in two 50m long snow trenches allowed us to create an unprecedented, two-dimensional image characterising the isotopic variations from the centimetre to the 100-metre scale. Our results show seasonal layering of the isotopic composition but also high horizontal isotopic variability caused by local stratigraphic noise. Based on the horizontal and vertical structure of the isotopic variations, we derive a statistical noise model which successfully explains the trench data. The model further allows one to determine an upper bound for the reliability of climate reconstructions conducted in our study region at seasonal to annual resolution, depending on the number and the spacing of the cores taken.…
Author details: | Thomas MünchORCiDGND, Sepp Kipfstuhl, Johannes Freitag, Hanno MeyerORCiDGND, Thomas LaeppleORCiDGND |
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URN: | urn:nbn:de:kobv:517-opus4-408385 |
DOI: | https://doi.org/10.25932/publishup-40838 |
ISSN: | 1866-8372 |
Title of parent work (English): | Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe |
Subtitle (English): | a two-dimensional view of water isotopes in Antarctic firn at Kohnen Station, Dronning Maud Land |
Publication series (Volume number): | Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe (500) |
Publication type: | Postprint |
Language: | English |
Date of first publication: | 2019/01/17 |
Publication year: | 2016 |
Publishing institution: | Universität Potsdam |
Release date: | 2019/01/17 |
Tag: | East Antarctica; Greenland; accumulation rates; diffusion; ice-core records; past 2 kyr; stable-isotopes; surface snow; temperature variability; time-series |
Issue: | 500 |
Number of pages: | 17 |
Source: | Climate of the Past 12 (2016), pp. 1565-1581 DOI: 10.5194/cp-12-1565-2016 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät |
DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer review: | Referiert |
Publishing method: | Open Access |
Grantor: | Copernicus |
License (German): | CC-BY - Namensnennung 4.0 International |