An Improved Continuous Flow Analysis System for High-Resolution Field Measurements on Ice Cores

2008 ◽  
Vol 42 (21) ◽  
pp. 8044-8050 ◽  
Author(s):  
Patrik R. Kaufmann ◽  
Urs Federer ◽  
Manuel A. Hutterli ◽  
Matthias Bigler ◽  
Simon Schüpbach ◽  
...  
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Flow Analysis ◽  
Ice Cores ◽  
Field Measurements ◽  
Continuous Flow Analysis ◽  
Analysis System

scholarly journals A High-Resolution Continuous Flow Analysis System for Polar Ice Cores

2016 ◽  
Vol 34 (0) ◽  
pp. 11-20 ◽  
Author(s):  
Rémi DALLMAYR ◽  
Kumiko GOTO-AZUMA ◽  
Helle ASTRID KJÆR ◽  
Nobuhiko AZUMA ◽  
Morimasa TAKATA ◽  
...  
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Flow Analysis ◽  
Ice Cores ◽  
Polar Ice ◽  
Continuous Flow Analysis ◽  
Analysis System

Forty years later: High resolution continuous flow analysis of the Dye3 ice core

2021 ◽  
Author(s):  
Helle Astrid Kjær ◽  
Margaret Harlan ◽  
Paul Vallelonga ◽  
Anders Svensson ◽  
Thomas Blunier ◽  
...  
Keyword(s):  
High Resolution ◽  
Forest Fires ◽  
Continuous Flow ◽  
Ice Core ◽  
Flow Analysis ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
The Core ◽  
Continuous Flow Analysis

<div><span><span>The Dye-3 ice core was drilled to bedrock at the Southern part of the central Greenland ice sheet (65°11'N, 43°50'W) in 1979-1981. The southern location is characterized by high accumulation rates compared to more central locations of the ice sheet. Since its drilling, numerous analyses of the core have been performed, and the ice has since been in freezer storage both in the USA and in Denmark.</span></span></div><div><span>In October and November 2019, the remaining ice, two mostly complete sections covering the depths of 1753–1820m and 1865–1918m of the Dye-3 core, were melted during a continuous flow analysis (CFA) campaign at the Physics of Ice, Climate, and Earth (PICE) group at the University of Copenhagen. The data represents both Holocene, Younger Dryas and Glacial sections (GS 5 to 12).</span></div><div> </div><div><span><span>The measured data consist chemistry and impurities contained in the ice, isotopes, as well as analysis of methane and other atmospheric gases. </span></span></div><div><span><span>The chemistry measurements include NH</span></span><span><span><sub>4</sub></span></span><span><span><sup>+</sup></span></span><span><span>, Ca</span></span><span><span><sup>2+</sup></span></span><span><span>, and Na</span></span><span><span><sup>+</sup></span></span><span><span> ions, which besides being influenced by transport, provide information about forest fires, wind-blown dust, and sea ice, respectively, as well as acidity, which aids in the identification of volcanic events contained in the core. The quantity and grain size distribution of insoluble particles was analyzed by means of an Abakus laser particle counter.</span></span></div><div> </div><div><span>We compare the new high-resolution CFA record of dye3 with previous analysis and thus evaluate the progress made over 40 years. Further we compare overlapping time periods with other central Greenland ice cores and discuss spatial patterns in relation to the presented climate proxies.</span></div>

Optimization of High-Resolution Continuous Flow Analysis for Transient Climate Signals in Ice Cores

2011 ◽  
Vol 45 (10) ◽  
pp. 4483-4489 ◽  
Author(s):  
Matthias Bigler ◽  
Anders Svensson ◽  
Ernesto Kettner ◽  
Paul Vallelonga ◽  
Maibritt E. Nielsen ◽  
...  
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Flow Analysis ◽  
Ice Cores ◽  
Continuous Flow Analysis ◽  
Climate Signals

A New Method for High-Resolution Methane Measurements on Polar Ice Cores Using Continuous Flow Analysis

2009 ◽  
Vol 43 (14) ◽  
pp. 5371-5376 ◽  
Author(s):  
Urs Federer ◽  
Patrik R. Kaufmann ◽  
Manuel A. Hutterli ◽  
Daphné Buiron ◽  
Thomas Blunier ◽  
...  
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Flow Analysis ◽  
Ice Cores ◽  
New Method ◽  
Polar Ice ◽  
Continuous Flow Analysis

scholarly journals High resolution aerosol concentration data from the Greenland NorthGRIP and NEEM deep ice cores

2021 ◽  
Author(s):  
Tobias Erhardt ◽  
Matthias Bigler ◽  
Urs Federer ◽  
Gideo Gfeller ◽  
Daiana Leuenberger ◽  
...  
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Ice Core ◽  
Historical Context ◽  
Flow Analysis ◽  
Ice Cores ◽  
Deposition Flux ◽  
Concentration Data ◽  
Continuous Flow Analysis ◽  
North Greenland

Abstract. Records of chemical impurities from ice cores enable us to reconstruct the past deposition of aerosols onto the polar ice sheets and alpine glaciers. Through that, they allow us to gain insight into changes of the source, transport and deposition processes that ultimately determine the deposition flux at the coreing location. However, the low concentrations of the aerosol species in the ice and the resulting high risk of contamination poses a formidable analytical challenge, especially if long, continuous and highly resolved records are needed. Continuous Flow Analysis, CFA, the continuous melting, decontamination and analysis of ice-core samples has mostly overcome this issue and has quickly become the de-facto standard to obtain high-resolution aerosol records from ice cores after its inception at the University of Bern in the mid 90s. Here we present continuous records of calcium (Ca2+), sodium (Na+), ammonium (NH4+), nitrate (NO3−1) and electrolytic conductivity at 1 mm depth resolution from the NGRIP (North Greenland Ice Core Project) and NEEM (North Greenland Eemian Ice Drilling) ice cores produced by the Bern Continuous Flow Analysis group in the years 2000 to 2011. Both of the records have previously been used in a number of studies but have never been published in the full 1 mm resolution. Alongside the 1 mm datasets we provide decadal averages, a detailed description of the methods, relevant references, an assessment of the quality of the data and its usable resolution. Along the way we will also give some historical context on the development of the Bern CFA system.

scholarly journals Calculating uncertainty for the RICE ice core continuous flow analysis water isotope record

2018 ◽  
Vol 11 (8) ◽  
pp. 4725-4736 ◽  
Author(s):  
Elizabeth D. Keller ◽  
W. Troy Baisden ◽  
Nancy A. N. Bertler ◽  
B. Daniel Emanuelsson ◽  
Silvia Canessa ◽  
...  
Keyword(s):  
High Resolution ◽  
Continuous Flow ◽  
Ice Core ◽  
Flow Analysis ◽  
Calibration Error ◽  
Data Set ◽  
Total Uncertainty ◽  
Continuous Flow Analysis ◽  
Uncertainty Estimates ◽  
Water Isotope

Abstract. We describe a systematic approach to the calibration and uncertainty estimation of a high-resolution continuous flow analysis (CFA) water isotope (δ2H, δ18O) record from the Roosevelt Island Climate Evolution (RICE) Antarctic ice core. Our method establishes robust uncertainty estimates for CFA δ2H and δ18O measurements, comparable to those reported for discrete sample δ2H and δ18O analysis. Data were calibrated using a time-weighted two-point linear calibration with two standards measured both before and after continuously melting 3 or 4 m of ice core. The error at each data point was calculated as the quadrature sum of three factors: Allan variance error, scatter over our averaging interval (error of the variance) and calibration error (error of the mean). Final mean total uncertainty for the entire record is δ2H=0.74 ‰ and δ18O=0.21 ‰. Uncertainties vary through the data set and were exacerbated by a range of factors, which typically could not be isolated due to the requirements of the multi-instrument CFA campaign. These factors likely occurred in combination and included ice quality, ice breaks, upstream equipment failure, contamination with drill fluid and leaks or valve degradation. We demonstrate that our methodology for documenting uncertainty was effective across periods of uneven system performance and delivered a significant achievement in the precision of high-resolution CFA water isotope measurements.

scholarly journals Improved methodologies for continuous-flow analysis of stable water isotopes in ice cores

2017 ◽  
Vol 10 (2) ◽  
pp. 617-632 ◽  
Author(s):  
Tyler R. Jones ◽  
James W. C. White ◽  
Eric J. Steig ◽  
Bruce H. Vaughn ◽  
Valerie Morris ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Ice Core ◽  
Flow Analysis ◽  
Ice Cores ◽  
Isotope Ratio Mass Spectrometry ◽  
Absorption Spectrometry ◽  
Isotopic Analysis ◽  
Water Isotopes ◽  
Stable Water Isotopes ◽  
Continuous Flow Analysis

Abstract. Water isotopes in ice cores are used as a climate proxy for local temperature and regional atmospheric circulation as well as evaporative conditions in moisture source regions. Traditional measurements of water isotopes have been achieved using magnetic sector isotope ratio mass spectrometry (IRMS). However, a number of recent studies have shown that laser absorption spectrometry (LAS) performs as well or better than IRMS. The new LAS technology has been combined with continuous-flow analysis (CFA) to improve data density and sample throughput in numerous prior ice coring projects. Here, we present a comparable semi-automated LAS-CFA system for measuring high-resolution water isotopes of ice cores. We outline new methods for partitioning both system precision and mixing length into liquid and vapor components – useful measures for defining and improving the overall performance of the system. Critically, these methods take into account the uncertainty of depth registration that is not present in IRMS nor fully accounted for in other CFA studies. These analyses are achieved using samples from a South Pole firn core, a Greenland ice core, and the West Antarctic Ice Sheet (WAIS) Divide ice core. The measurement system utilizes a 16-position carousel contained in a freezer to consecutively deliver  ∼  1 m  ×  1.3 cm2 ice sticks to a temperature-controlled melt head, where the ice is converted to a continuous liquid stream and eventually vaporized using a concentric nebulizer for isotopic analysis. An integrated delivery system for water isotope standards is used for calibration to the Vienna Standard Mean Ocean Water (VSMOW) scale, and depth registration is achieved using a precise overhead laser distance device with an uncertainty of ±0.2  mm. As an added check on the system, we perform inter-lab LAS comparisons using WAIS Divide ice samples, a corroboratory step not taken in prior CFA studies. The overall results are important for substantiating data obtained from LAS-CFA systems, including optimizing liquid and vapor mixing lengths, determining melt rates for ice cores with different accumulation and thinning histories, and removing system-wide mixing effects that are convolved with the natural diffusional signal that results primarily from water molecule diffusion in the firn column.

Continuous Flow Analysis Method for Determination of Dissolved Reactive Phosphorus in Ice Cores

2013 ◽  
Vol 47 (21) ◽  
pp. 12325-12332 ◽  
Author(s):  
Helle Astrid Kjær ◽  
Paul Vallelonga ◽  
Anders Svensson ◽  
Magnus Elleskov L. Kristensen ◽  
Catalin Tibuleac ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Analysis ◽  
Ice Cores ◽  
Analysis Method ◽  
Continuous Flow Analysis ◽  
Dissolved Reactive Phosphorus ◽  
Reactive Phosphorus

A Semi-Automated Method for the Determination of Ammonia in Urine using the Nessler Reaction

1974 ◽  
Vol 11 (1-6) ◽  
pp. 137-140 ◽  
Author(s):  
T. F. Hartley
Keyword(s):  
Ammonium Chloride ◽  
Continuous Flow ◽  
Flow Analysis ◽  
Zinc Hydroxide ◽  
Automated Method ◽  
Continuous Flow Analysis ◽  
Analar Grade ◽  
Analysis System

Species in urine which were likely to interfere with the determination of ammonia by Nesslerisation were adsorbed onto a precipitate of zinc hydroxide formed in situ in each sample. The ammonia concentrations in the subsequent supernatant solutions were measured using the Nessler method, adapted for use on a continuous flow analysis system. These measurements were made against a series of standards prepared from Analar grade ammonium chloride. The accuracy, reproducibility, and sensitivity of this adaptation were examined and were found to be within acceptable limits.

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