A5083786274- Geology and Paleoclimatology Research
- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Methane Hydrates and Related Phenomena
- Isotope Analysis in Ecology
- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Arctic and Antarctic ice dynamics
- Climate variability and models
- Atmospheric chemistry and aerosols
- Pleistocene-Era Hominins and Archaeology
- Winter Sports Injuries and Performance
- Climate change and permafrost
- Paleontology and Stratigraphy of Fossils
- Astro and Planetary Science
- Marine and environmental studies
- Radioactive contamination and transfer
- High Altitude and Hypoxia
- Laser Design and Applications
- Geomagnetism and Paleomagnetism Studies
- Meteorological Phenomena and Simulations
- Geophysics and Gravity Measurements
- Mass Spectrometry Techniques and Applications
- Space Exploration and Technology
- Groundwater and Isotope Geochemistry
University of Bern
2012-2023
Oeschger Centre for Climate Change Research
2012-2023
Swiss Federal Laboratories for Materials Science and Technology
2018-2023
University of California, San Diego
2014-2023
Scripps Institution of Oceanography
2014-2023
Bruker (Switzerland)
2020
Abstract The European Project for Ice Coring in Antarctica Dome ice core from C (EDC) has allowed the reconstruction of atmospheric CO 2 concentrations last 800,000 years. Here we revisit oldest part EDC record using different air extraction methods and sections core. For our established cracker system, found an analytical artifact, which increases over deepest 200 m reaches 10.1 ± 2.4 ppm oldest/deepest part. governing mechanism is not yet fully understood, but it related to insufficient...
Important elements of natural climate variations during the last ice age are abrupt temperature increases over Greenland and related warming cooling periods Antarctica. Records from Antarctic cores have shown that global carbon cycle also plays a role in these changes. The available data shows atmospheric CO(2) follows closely temperatures reconstructed variations. Here, we present new high-resolution cores, which cover period between 115,000 38,000 y before present. Our measurements show...
Abstract We present new δ 13 C measurements of atmospheric CO 2 covering the last glacial/interglacial cycle, complementing previous records Terminations I and II. Most prominent in record is a significant depletion C(atm) 0.5‰ occurring during marine isotope stage (MIS) 4, followed by an enrichment same magnitude at beginning MIS 3. Such excursion otherwise only observed glacial terminations, suggesting that similar processes were play, such as changing sea surface temperatures, changes...
Pulses of the past Bursts carbon dioxide, released into atmosphere and occurring on centennial time scales, were seen during cold periods last glacial cycle but not in older or warmer conditions. Nehrbass-Ahles et al. present a record atmospheric dioxide concentrations retrieved from European Project for Ice Coring Antarctica Dome C ice core showing that these jumps occurred both warm between 330,000 450,000 years ago. They relate pulses to disruptions Atlantic meridional overturning...
The global ocean constitutes the largest heat buffer in climate system, but little is known about its past changes. isotopic and elemental ratios of heavy noble gases (krypton xenon), together with argon nitrogen trapped air from ice cores, can be used to reconstruct mean temperatures (MOTs). Here we introduce two successively developed methods measure these parameters a sufficient precision provide new constraints on changes MOT.The an 800-g sample - containing roughly 80 mL STP extracted...
High precision mobile sensing of multi-species gases is greatly demanded in a wide range applications. Although quantum cascade laser absorption spectroscopy demonstrates excellent field-deployment capabilities for gas sensing, the implementation this measurement technique into sensor-like portable instrumentation still remains challenging. In paper, two crucial elements, driving and data acquisition electronics, are addressed. Therefore, we exploit benefits time-division multiplexed...
Abstract. An important share of paleoclimatic information is buried within the lowermost layers deep ice cores. Because improving our records further back in time one main challenges near future, it essential to judge how these remain unaltered, since proximity bedrock likely interfere both with recorded temporal sequence and properties. In this paper, we present a multiparametric study (δD-δ18Oice, δ18Oatm, total air content, CO2, CH4, N2O, dust, high-resolution chemistry, texture) bottom...
Abstract. In the framework of International Partnerships in Ice Core Sciences, one most important targets is to retrieve an Antarctic ice core that extends over last 1.5 million years (i.e. enters climate era when glacial–interglacial cycles followed obliquity earth). such annual layers oldest would be thinned by a factor about 100 and climatic information 10 000 yr interval contained less than 1 m ice. The gas record can potentially reveal role greenhouse forcing on these 40 cycles....
Abstract Noble gases in ice cores enable reconstructions of past mean ocean temperature. A recent result from the clathrate‐containing WAIS Divide Ice Core showed tight covariation between and Antarctic temperatures throughout last deglaciation, except for Younger Dryas interval. In beginning this interval, oceans warmed at 2.5 °C/kyr—three times greater than estimates modern warming. If valid, challenges our understanding mechanisms controlling heat uptake. Here we reconstruct temperature...
Polar ice cores are unique archives for ancient air. However, a loss of air due to molecular diffusion during storage could affect the composition remaining We formulate model with high spatial resolution (1 mm) calculating N 2 , O and CO in pure clathrate order determine which layers an core affected by significant changes concentration δ (O /N ) ratio durations up 38 years. The results agree experimental measurements at pieces performed after different durations. Additionally, calculations...
Abstract. Using new and previously published CO2 data from the EPICA Dome C ice core (EDC), we reconstruct a high-resolution record of atmospheric during Marine Isotope Stage (MIS) 6 (190 to 135 ka) penultimate glacial period. Similar last cycle, where already exists, our shows that longer North Atlantic (NA) stadials, millennial variations MIS are clearly coincident with bipolar seesaw signal in Antarctic temperature record. However, one short stadial NA, variation is small (∼5 ppm)...
Abstract. Precision, accuracy, and temporal resolution are key to making full use of atmospheric trace gas records in ice cores. These aspects will become especially crucial for cores that aim extend the core record last 1.5 Myr, i.e., across Mid-Pleistocene Transition (as currently drilled within European project Beyond EPICA – Oldest Ice Core (BE-OIC)). The from this period is expected be close bedrock and, due glacier flow, extremely thinned with 15 000 years climate history contained...
Abstract. For atmospheric CO2 reconstructions using ice cores, the technique to release trapped air from samples is essential for precision and accuracy of measurements. We present here a new dry extraction in combination with gas analytical system that together show significant improvements respect current systems. Ice (3–15 g) are pulverised novel centrifugal microtome (CIM) by shaving cooled vacuum chamber (−27 °C) which no friction occurs due use magnetic bearings. Both, principle CIM...
Abstract. Cosmic rays entering the Earth's atmosphere produce showers of secondary particles such as protons, neutrons, and muons. The interaction these with oxygen-16 (16O) in minerals ice quartz can carbon-14 (14C). In glacial ice, 14C is also incorporated through trapping 14C-containing atmospheric gases (14CO2, 14CO, 14CH4). Understanding production rates situ cosmogenic important to deconvolve signals both which contain valuable paleoenvironmental information. Unfortunately, by muons...
Abstract. Here we present a newly developed ice core gas-phase proxy that directly samples component of the large-scale atmospheric circulation: synoptic-scale pressure variability. Surface changes weakly disrupt gravitational isotopic settling in firn layer, which is recorded krypton-86 excess (86Krxs). The 86Krxs may therefore reflect time-averaged synoptic variability over several years (site “storminess”), but it likely cannot record individual events as gas typically average years. We...
Abstract. The record of past greenhouse gas composition from ice cores is crucial for our understanding global climate change. Future core projects will aim to extend both the temporal coverage (extending timescale 1.5 Myr) and resolution existing records. This implies a strongly limited sample availability, increasing demands on analytical accuracy precision, need reuse air samples extracted multiple analyses. To meet these requirements, we designed developed new system that combines direct...
Abstract. In the framework of International Partnerships in Ice Core Sciences, one most important target is to retrieve an Antarctic ice core that extends over last 1.5 million years, i.e. enters climate era when glacial-interglacial cycles followed obliquity sun. such annual layers oldest would be thinned by a factor about 100 and climatic information 10 000 yr interval contained less than 1m ice. The gas record can potentially reveal role greenhouse forcing on these 40 cycles. However,...
Abstract. Atmospheric trace gas measurements of greenhouse gases are critical in their precision and accuracy. In the past 5 years, atmospheric measurement metrology communities have turned attention to possible surface effects due pressure temperature variations during a standard cylinder's lifetime. This study concentrates on this issue by introducing newly built small-volume aluminum steel cylinders which enable investigation affinity for adsorption desorption various surfaces over set...