| 1. |
- Erhardt, Tobias, et al.
(författare)
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High-resolution aerosol data from the top 3.8kyr of the East Greenland Ice coring Project (EGRIP) ice core
- 2023
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Ingår i: Earth System Science Data. - 1866-3508. ; 15:11, s. 5079-5091
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Tidskriftsartikel (refereegranskat)abstract
- Here we present the high-resolution continuous flow analysis (CFA) data from the top 479m of the East Greenland Ice coring Project (EGRIP) ice core covering the past 3.8kyr. The data consist of 1mm depth-resolution profiles of calcium, sodium, ammonium, nitrate, and electrolytic conductivity as well as decadal averages of these profiles. The nominally 1mm data represent an oversampling of the record as the true resolution is limited by the analytical setup to approximately 1cm. Alongside the data we provide a description of the measurement setup, procedures, the relevant references for the specific methods as well as an assessment of the precision of the measurements, the sample-to-depth assignment, and the depth and temporal resolution of the data set. The error in absolute depth assignment of the data may be on the order of 2cm; however, relative depth offsets between the records of the individual species are only on the order of 1mm. The presented data have sub-annual resolution over the entire depth range and have already formed part of the data for an annually layer-counted timescale for the EGRIP ice core used to improve and revise the multi-core Greenland ice-core chronology (GICC05) to a new version, GICC21 . The data are available in full 1mm resolution and decadal averages on PANGAEA (10.1594/PANGAEA.945293, ).
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| 2. |
- Spolaor, Andrea, et al.
(författare)
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Climate change is rapidly deteriorating the climatic signal in Svalbard glaciers
- 2024
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Ingår i: CRYOSPHERE. - 1994-0416 .- 1994-0424. ; 18:1, s. 307-320
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Tidskriftsartikel (refereegranskat)abstract
- The Svalbard archipelago is particularly sensitive to climate change due to the relatively low altitude of its main ice fields and its geographical location in the higher North Atlantic, where the effect of Arctic amplification is more significant. The largest temperature increases have been observed during winter, but increasing summer temperatures, above the melting point, have led to increased glacier melt. Here, we evaluate the impact of this increased melt on the preservation of the oxygen isotope ( delta 18 O) signal in firn records. delta 18 O is commonly used as a proxy for past atmospheric temperature reconstructions, and, when preserved, it is a crucial parameter to date and align ice cores. By comparing four different firn cores collected in 2012, 2015, 2017 and 2019 at the top of the Holtedahlfonna ice field (1100 m a.s.l.), we show a progressive deterioration of the isotope signal, and we link its degradation to the increased occurrence and intensity of melt events. Our findings indicate that, starting from 2015, there has been an escalation in melting and percolation resulting from changes in the overall atmospheric conditions. This has led to the deterioration of the climate signal preserved within the firn or ice. Our observations correspond with the model's calculations, demonstrating an increase in water percolation since 2014, potentially reaching deeper layers of the firn. Although the delta 18 O signal still reflects the interannual temperature trend, more frequent melting events may in the future affect the interpretation of the isotopic signal, compromising the use of Svalbard ice cores. Our findings highlight the impact and the speed at which Arctic amplification is affecting Svalbard's cryosphere.
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