Papers by Damiano Della Lunga
Figure S1: LA-ICPMS instrumental drift correction. The data points represent NIST612 values acqui... more Figure S1: LA-ICPMS instrumental drift correction. The data points represent NIST612 values acquired in between the ice samples during a single run. Sensitivity typically decreases slightly during the analysis and the slope of each element's regression line has been utilized to correct instrumental drift according to eq.1 (See text for details).
Sea ice is a key component of the climate system, since it modifies the surface albedo, the radia... more Sea ice is a key component of the climate system, since it modifies the surface albedo, the radiation balance, as well as the 10 exchange of heat, moisture and gases between the ocean and the overlying atmosphere. Hence, the reconstruction of sea ice cover before the instrumental era and the industrial times is crucial to understand the evolution of Arctic climate in the last millennium and better predict its future evolution. However, identifying relevant paleo proxies in climate archives related to sea ice cover is not straightforward. Ice cores from polar regions offer great potential to provide high-resolution records of Arctic sea ice variability from chemical impurities such as Bromine species, which were recently proposed as indicators of 15 sea ice extent, although their variability might be modulated by regional influences. We here use Bromine and Bromine enrichment of two ice cores form North Greenland (B17 & B26) and investigate its potential as proxy to reconstruct sea ice extent over the period 1363-1993 AD. Across the instrumental period, a good correlation is observed with the Baffin Bay and the Greenland Sea for B26 and B17 respectively, with both record showing minima corresponding to known Artic warming events such as the 1420 AD (for B17) and 1920-1940 (Early century warming, B17 & B26), together with a strong 20 decline starting in the late 19 th century. We simultaneously derived a chemical classification of sea ice-related contributors of ionic species (i.e. blowing snow, frost flowers, open water) utilizing the depletion of SO4 2-compare to Ca 2+ , K + and Mg 2+ characterizing sea ice brines and blowing snow as well the excess of Br -and Cl -, characterizing frost flowers, to elucidate the evolution of the different sources. In both B17 and B26 records we observe a strong contribution of blowing snow in the earliest part of the datasets, gradually declining in recent years in favour of open water sources. 25 over the course of a decade (Grosfeld et al., 2016). Furthermore, a compilation of various Arctic data sets from laser altimetry and electromagnetic sounding shows that also the average thickness of summer sea ice in the central Arctic Ocean
The validity of any glaciological paleo proxy used to interpret climate records is based on the l... more The validity of any glaciological paleo proxy used to interpret climate records is based on the level of understanding of their transfer from the atmosphere into the ice sheet and their recording in the snowpack. Large spatial noise in snow properties is observed, as the wind constantly redistributes the deposited snow at the surface routed by the local topography. To increase the signal-tonoise ratio and getting a representative estimate of snow properties with respect to the high spatial variability, a large number of snow profiles is needed. However, the classical way of obtaining profiles via snow-pits is time and energy-consuming, and thus unfavourable for large surface sampling programs. In response, we present a dual-tube technique to sample the upper metre of the snowpack at a variable depth resolution with high efficiency. The developed device is robust and avoids contact with the samples by exhibiting two tubes attached alongside each other in order to (1) contain the snow core sample and (2) to access the bottom of the sample, respectively. We demonstrate the performance of the technique through two case studies in East Antarctica where we analysed the variability of water isotopes at a 100 m and 5 km spatial scales.
Science of The Total Environment, Mar 1, 2019
Volcanic eruptions are widely used in ice core science to date or synchronize ice cores. Volcanoe... more Volcanic eruptions are widely used in ice core science to date or synchronize ice cores. Volcanoes emit large amounts of SO 2 that is subsequently converted in the atmosphere into sulfuric acid/sulphate. Its discrete and continuous quantification is currently used to determine the ice layers impacted by volcanic emissions, but available high-resolution sulphate quantification methods in ice core (Continuous Flow Analysis (CFA)) struggle with insufficient sensitivity. Here, we present a new high-resolution CFA chemiluminescence method for the continuous determination of Fe 2+ species in ice cores that shows clear Fe 2+ peaks concurrent with volcanic sulphate peaks in the ice core record. The method, applied on a Greenland ice core, correctly identifies all volcanic eruptions from between 1588 to 1611 and from 1777 to 1850. The method has a detection limit of ∽5 pg g -1 and a quadratic polynomial calibration range of up to at least 1760 pg g -1 . Our results show that Fe 2+ is a suitable proxy for identifying past volcanic events.
New proxy to identify past volcanic eruptions in ice cores
EGU General Assembly Conference Abstracts, Apr 1, 2019
Evidence for Elemental Dust Proxies abrupt changes across Dansgaard-Oeschger events inferred by UV-LA-ICPMS on NGRIP ice cores
EGUGA, Apr 1, 2017
Major elemental concentrations from NGRIP ice core across the interstadial period GI-21.2
Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer ... more Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer conditions (Greenland interstadials, GI) called Dansgaard-Oeschger events are recorded in the Greenland ice cores. Using cryo-cell UV-laser-ablation inductively-coupled-plasma mass spectrometry (UV-LA-ICPMS), we analysed a 2.85 m NGRIP ice core section (~ 250 years; 2691.50–2688.65 m depth) across the transitions of GI-21.2, a short-lived interstadial prior to interstadial GI-21.1 (GI-21.2: 84.87–85.09 ka b2k). GI-21.2 is a ~100-year-long period with d18O values 3–4 per mil higher than the following ~200 years of stadial conditions (GS-21.2), which precede the major GI-21.1 warming. We report concentrations of "major" elements indicative of dust and/or sea salt (Na, Fe, Al, Ca, Mg) at a spatial resolution of ~ 200 µm, while maintaining detection limits in the low-ppb range, thereby achieving sub-annual time resolution even in deep NGRIP ice. We present an improved external calibration and quantification procedure using a set of five ice standards made from aqueous (international) standard solutions. Our results show that element concentrations decrease drastically (more than tenfold) at the warming onset of GI-21.2 at the scale of a single year, followed by relatively low concentrations characterizing the interstadial part before gradually reaching again typical stadial values.
Atmospheric Chemistry and Physics, Oct 31, 2020
Ice-nucleating particles (INPs) affect the microphysics in cloud and precipitation processes. Hen... more Ice-nucleating particles (INPs) affect the microphysics in cloud and precipitation processes. Hence, they modulate the radiative properties of clouds. However, atmospheric INP concentrations of the past are basically unknown. Here, we present INP measurements from an ice core in Greenland, which dates back to the year 1370. In total 135 samples were analyzed with the FRIDGE droplet freezing assay in the temperature range from -14 to -35 • C. The sampling frequency was set to 1 in 10 years from 1370 to 1960. From 1960 to 1990 the frequency was increased to one sample per year. Additionally, a few special events were probed, including volcanic episodes. The typical time coverage of a sample was on the order of a few months. Historical atmospheric INP concentrations were estimated with a conversion factor, which depends on the snow accumulation rate of the ice core, particle dry deposition velocity, and wet scavenging ratio. Typical atmospheric INP concentrations were on the order of 0.1 L -1 at -25 • C. The INP variability was found to be about 1-2 orders of magnitude. Yet, the short-term variability from samples over a seasonal cycle was considerably lower. INP concentrations were significantly correlated to some chemical tracers derived from continuous-flow analysis (CFA) and ion chromatography (IC) over a broad range of nucleation temperatures. The highest correlation coefficients were found for the particle concentration (spherical diameter d p > 1.2 µm). The correlation is higher for a time period of seasonal samples, where INP concentrations follow a clear annual pattern, highlighting the importance of the annual dust input in Greenland from East Asian deserts during spring. Scanning electron microscopy (SEM) analysis of selected samples found mineral dust to be the dominant particle fraction, verifying their significance as INPs. Overall, the concentrations compare reasonably well to present-day INP concentrations, albeit they are on the lower side. However, we found that the INP concentration at medium supercooled temperatures differed before and after 1960. Average INP concentrations at -23, -24, -25, -26, and -28 • C were significantly higher (and more variable) in the modern-day period, which could indicate a potential anthropogenic impact, e.g., from land-use change.
The Cryosphere, May 31, 2017
Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer ... more Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer conditions (Greenland interstadials, GI) called Dansgaard-Oeschger events are recorded in the Greenland ice cores. Using cryo-cell UV-laser-ablation inductively coupled-plasma mass spectrometry (UV-LA-ICPMS), we analysed a 2.85 m NGRIP ice core section (2691.50-2688.65 m depth, age interval 84.86-85.09 ka b2k, thus covering ∼ 230 years) across the transitions of GI-21.2, a short-lived interstadial prior to interstadial GI-21.1. GI-21.2 is a ∼ 100-year long period with δ 18 O values 3-4 ‰ higher than the following ∼ 200 years of stadial conditions (GS-21.2), which precede the major GI-21.1 warming. We report concentrations of "major" elements indicative of dust and/or sea salt (Na, Fe, Al, Ca, Mg) at a spatial resolution of ∼ 200 µm, while maintaining detection limits in the low-ppb range, thereby achieving sub-annual time resolution even in deep NGRIP ice. We present an improved external calibration and quantification procedure using a set of five ice standards made from aqueous (international) standard solutions. Our results show that element concentrations decrease drastically (more than 10fold) at the warming onset of GI-21.2 at the scale of a single year, followed by relatively low concentrations characterizing the interstadial part before gradually reaching again typical stadial values.
Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer ... more Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer conditions (Greenland interstadials, GI) called Dansgaard-Oeschger events are recorded in the Greenland ice cores. Using cryo-cell UV-laserablation inductively-coupled-plasma mass spectrometry (UV-LA-ICPMS), we analysed a 2.85 m NGRIP ice core section (~250 years; 2691.50 -2688.65 m depth) across the transitions of GI-21.2, a short-lived interstadial prior to interstadial GI-21.1 (GI-21.2: 84.87 -85.09 ka b2k). GI-21.2 is a ~100-year-long period with δ 18 O values 3 -4‰ higher than the following ~200 years of stadial conditions (GS-21.2), which precede the major GI-21.1 warming. We report concentrations of 'major' elements indicative of dust and/or sea salt (Na, Fe, Al, Ca, Mg) at a spatial resolution of ~200 μm, while maintaining detection limits in the low-ppb range, thereby achieving sub-annual time resolution even in deep NGRIP ice. We present an improved external calibration and quantification procedure using a set of five ice standards made from aqueous (international) standard solutions. Our results show that element concentrations decrease drastically (more than tenfold) at the warming onset of GI-21.2 at the scale of a single year, followed by relatively low concentrations characterizing the interstadial part before gradually reaching again typical stadial values.
Ice cores from Greenland preserve a continuous ~125 kyrs record of climate change at very high re... more Ice cores from Greenland preserve a continuous ~125 kyrs record of climate change at very high resolution. The most remarkable of these changes are Dansgaard-Oeschger (DO) cycles, which are characterized by very rapid Greenland temperature shifts of 5-16°C recorded in δO and reflected in many other proxies such as dust (Ca, Al, Fe) and sea salt (Na, Mg). DO events also are recorded in other northern and southern hemisphere archives such as speleothems and thus show the large-scale extent of these climate variations. By applying cryo-cell UV-LA-ICPMS (Ultra-Violet Laser-Ablation InductivelyCoupled-Plasma-Mass-Spectrometry) directly to frozen NGRIP ice samples, we investigated elemental proxies of dust and sea salt at an unprecedented spatial resolution of ≤200 μm while maintaining ppb detection limits. For the investigated DO event 22 (87.6-84.7 ka), we thus achieve approximately bimonthly time resolution. Using a series of suitably homogenous reference ice standards specifically pre...
Summary Relatively high nitrogen contents are found in Carboniferous rocks in the southern part o... more Summary Relatively high nitrogen contents are found in Carboniferous rocks in the southern part of the D&E-blocks in the Netherlands offshore area. Unfortunately, data are lacking for the northern D&E-blocks, which are open for exploration. This report aims to explain the observed nitrogen contents in the southern part of the D&E-blocks, which might help predict nitrogen contents further north. A few factors possibly cause enhanced nitrogen contents in the study area. First, due to a low maturity in the northern part of the E-blocks, the succession might still be (partly) in the "early nitrogen" phase of generation (prior to the main gas generation phase). Secondly, limited availability of high-quality source rocks in the northern part of the E-blocks might have led to a relative enrichment in nitrogen. The influence of volcanic rocks is another factor that has to be taken into account. Local heating might have caused local enhanced generation of nitrogen, possibly from sh...
5km-scale isotopic (δ18O) variability of the top-meter between locations B50 and B49, East Antarctica
Intermediate-scale (5 kilometers) isotopic composition of the top-meter of the snowpack around Ko... more Intermediate-scale (5 kilometers) isotopic composition of the top-meter of the snowpack around Kohnen station, Dronning-Maud Land, East-Antarctica. The snow was sampled with the dual-tube sampling technique and the isotopic analysis were realized by CRDS (Cavity-Ring-Down Spectroscopy, l2130-i, Picarro Inc.) at the Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung, in Bremerhaven, Germany
New proxy to identify past volcanic eruptions in ice cores
EGU General Assembly Conference Abstracts, Apr 1, 2019
Evidence for Elemental Dust Proxies abrupt changes across Dansgaard-Oeschger events inferred by UV-LA-ICPMS on NGRIP ice cores
EGUGA, Apr 1, 2017
Ice nucleating particle concentrations by droplet freezing assay measurements from the B17 ice core, Greenland, dating from 1370 to 1990
The data set reports on measurements of ice nucleating particles (INPs) from an ice core in Green... more The data set reports on measurements of ice nucleating particles (INPs) from an ice core in Greenland (B17, 72.25, -37.25, 2820 m AMSL) that dates back to about 1370. INP measurements were performed using the FRIDGE INP counter as a droplet freezing assay for N = 135 meltwater samples from the core. From each sample 3 x 65 droplets of melt water (2.5 µL) were pipetted onto a sample substrate. The experimental nucleation temperature T was decreased at 1 °C/min until every droplet was frozen. The frozen fraction (FF) as a function of T is used to calculate the INP abundance per mL of melt water. A conversion factor is used to estimate atmospheric INP concentrations. The typical time coverage of a sampe is in the order of a couple of months. Samples were selected in regular time intervals of 10 years, plus a number of additional samples. This data supplement is related to a scientific publication (doi:10.5194/acp-2020-556).
100m-scale isotopic (δ18O) variability of the top-meter at location B52, East Antarctica
Small-scale (100 meter) isotopic composition of the top-meter of the snowpack around Kohnen stati... more Small-scale (100 meter) isotopic composition of the top-meter of the snowpack around Kohnen station, Droning-Maud Land, East-Antarctica. The snow was sampled with the dual-tube sampling technique and the isotopic analysis were realized by CRDS (Cavity-Ring-Down Spectroscopy, l2130-i, Picarro Inc.) at the Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung, in Bremerhaven, Germany.
Major elemental concentrations from NGRIP ice core across the interstadial period GI-21.2
Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer ... more Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer conditions (Greenland interstadials, GI) called Dansgaard-Oeschger events are recorded in the Greenland ice cores. Using cryo-cell UV-laser-ablation inductively-coupled-plasma mass spectrometry (UV-LA-ICPMS), we analysed a 2.85 m NGRIP ice core section (~ 250 years; 2691.50–2688.65 m depth) across the transitions of GI-21.2, a short-lived interstadial prior to interstadial GI-21.1 (GI-21.2: 84.87–85.09 ka b2k). GI-21.2 is a ~100-year-long period with d18O values 3–4 per mil higher than the following ~200 years of stadial conditions (GS-21.2), which precede the major GI-21.1 warming. We report concentrations of "major" elements indicative of dust and/or sea salt (Na, Fe, Al, Ca, Mg) at a spatial resolution of ~ 200 µm, while maintaining detection limits in the low-ppb range, thereby achieving sub-annual time resolution even in deep NGRIP ice. We present an improved external calibration and quantification procedure using a set of five ice standards made from aqueous (international) standard solutions. Our results show that element concentrations decrease drastically (more than tenfold) at the warming onset of GI-21.2 at the scale of a single year, followed by relatively low concentrations characterizing the interstadial part before gradually reaching again typical stadial values.
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Papers by Damiano Della Lunga