A5042227278- Cryospheric studies and observations
- Arctic and Antarctic ice dynamics
- Climate change and permafrost
- Winter Sports Injuries and Performance
- Landslides and related hazards
- Methane Hydrates and Related Phenomena
- Icing and De-icing Technologies
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Geological Studies and Exploration
- Hydrology and Watershed Management Studies
- Nuclear Materials and Properties
- Outdoor and Experiential Education
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Science and Climate Studies
- Meteorological Phenomena and Simulations
- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
Swiss Federal Institute for Forest, Snow and Landscape Research
2020-2023
Paul Scherrer Institute
2006
Year-round observations of the physical snow and ice properties processes that govern pack evolution its interaction with atmosphere ocean were conducted during Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) expedition research vessel Polarstern in Ocean from October 2019 to September 2020. This work was embedded into interdisciplinary design 5 MOSAiC teams, studying atmosphere, sea ice, ocean, ecosystem, biogeochemical processes. The overall aim characterize cover...
Repeated transects have become the backbone of spatially distributed ice and snow thickness measurements crucial for understanding mass balance. Here we detail at Multidisciplinary drifting Observatory Study Arctic Climate (MOSAiC) 2019–2020, which represent first such collected across an entire season. Compared with similar historical transects, MOSAiC was thin (mean depths approximately 0.1–0.3 m), while sea relatively thick first-year (FYI) second-year (SYI). SYI two distinct types: level...
Abstract. Data from the Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition allowed us to investigate temporal dynamics snowfall, snow accumulation and erosion in great detail almost whole season (November 2019 May 2020). We computed cumulative water equivalent (SWE) over sea ice based on depth density retrievals a SnowMicroPen approximately weekly measured depths along fixed transect paths. used derived SWE cover compare with precipitation sensors...
Abstract We present an improved machine to produce nature-identical snow in a cold laboratory for reproducible experiments. The is based on the common supersaturation principle of blowing air over heated water basin. moist airstream directed into chamber, where it cools and nucleation ice crystals promoted stretched nylon wires. Snow grow wires are harvested regularly by new automatic brush rack. Depending settings, different can be produced, which shown consistent with Nakaya diagram. main...
The role of near-surface snow processes for the formation climate signals through densification into deep polar firn is still barely understood. To this end we have analyzed a shallow pit (0-3 meters) from EastGRIP (Greenland) and derived high-resolution profiles different types mechanically relevant fabric tensors. structural fabric, which characterizes anisotropic geometry ice matrix pore space, was obtained by X-ray tomography. crystallographic distribution c-axis (or optical axis)...
Abstract. The necessity of characterizing snow through objective, physically motivated parameters has led to new model formulations and measurement techniques. Consequently, essential structural such as density specific surface area (for basic characterization) or mechanical the critical crack length avalanche stability gradually replace semiempirical indices acquired from traditional stratigraphy. These advances come along with demands potentials for validation. To this end, we conducted...
Landfast ice plays a significant role in climate and ecosystems Antarctic coastal regions. From October to December 2022, we investigated the physical properties of snow sea on landfast McMurdo Sound, following protocols from MSOAiC expedition. Our measurements confirmed some findings MOSAiC (e.g. potential mass transfer surface , high spatial variability depth}, discrepancy between meteorological snowfall accumulation),  but also had observations that were contrasting our data, for...
Abstract Snow plays an essential role in the Arctic as interface between sea ice and atmosphere. Optical properties, thermal conductivity mass distribution are critical to understanding complex system’s energy balance distribution. By conducting measurements from October 2019 September 2020 on Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition, we have produced a dataset capturing year-long evolution physical properties snow surface scattering layer, highly...
Precise measurements of Arctic sea ice mass balance are necessary to understand the rapidly changing cover and its representation in climate models. During Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition, we made repeat point snow thickness on primarily level first- second-year (FYI, SYI) using ablation stakes gauges. This technique enabled us distinguish surface bottom (basal) melt characterize importance oceanic versus atmospheric forcing. We also evaluated...
Abstract. Data from the Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition allowed us to investigate temporal dynamics snowfall, snow accumulation, and erosion in great detail almost whole accumulation season (November 2019 May 2020). We computed cumulative water equivalent (SWE) over sea ice based on depth (HS) density retrievals a SnowMicroPen (SMP) approximately weekly-measured depths along fixed transect paths. Hence, SWE considers surface...
Snow and ice topography impact are impacted by fluxes of mass, energy, momentum in Arctic sea ice. We measured the on approximately a 0.5 km
Abstract Snow depth on sea ice is an Essential Climate Variable and a major source of uncertainty in satellite altimetry‐derived thickness. During winter the MOSAiC Expedition, “KuKa” dual‐frequency, fully polarized Ku‐ Ka‐band radar was deployed “stare” nadir‐looking mode to investigate possibility combining these two frequencies retrieve snow depth. Three approaches were investigated: dual‐polarization waveform shape, compared independent measurements. Novel yielded r 2 values up 0.77....
Compression of snow at low strain rates governs the natural densification and firn on Earth. Different deformation mechanisms (e.g., grain boundary sliding dislocation creep) are widely employed in models mainly believed to change depending relative density or type. To explore this picture, we conducted compression experiments with a nominally constant rate ɛ̇≈10−6s−1 systematically varied type, density, specific surface area. We used micro-compression stage enable X-ray micro-tomography...
Abstract. The necessity of characterizing snow through objective, physically-motivated parameters has led to new model formulations and measurement techniques. Consequently, essential structural such as density specific surface area (for basic characterization) or mechanical the critical crack length avalanche stability gradually replace semi-empirical indices acquired from traditional stratigraphy. These advances come along with demands potentials for validation. To this end, we conducted...
Abstract The sub-kilometre scale distribution of snow depth on Arctic sea ice impacts atmosphere-ice fluxes energy and mass, is importance for satellite estimates sea-ice thickness from both radar lidar altimeters. While information about the mean this increasingly available modelling remote sensing, full cannot yet be resolved. We analyse 33 539 measurements 499 transects taken at Soviet drifting stations between 1955 1991 derive a simple statistical over multi-year as function only depth....
Abstract. Sea ice thickness is essential for climate studies and numerical weather prediction. Radar altimetry has provided sea measurement since the launch of ERS-1 currently through CryoSat-2, Sentinel-3 Altika but uncertainty in scattering horizon used to retrieve arises from interactions between emitted signal snow cover on surface. Therefore, modelling electromagnetic waves with snowpack necessary accurately. The Snow Microwave Radiative Transfer (SMRT) model was simulate low resolution...
Photochemical release of iodine from snow has been suggested as a source reactive to the Arctic atmosphere, however understanding underlying mechanism and potential strength is hindered by lack measurements concentration speciation in snow. Moreover, origin also unknown. Here, we report on sea ice at range depths 177 samples, representing 80 sampling events, December 2019 October 2020 collected during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition. We...
<p>Sea ice plays a critical role in the Arctic climate system, regulating much of energy transfer between ocean and atmosphere. Repeat measurements mass balance at discrete points allow us to determine direct response sea environmental conditions. We installed network measurement sites across MOSAiC Central Observatories, distributed over diverse range types features. The were composed gridded arrays 9-17 hotwire thickness gauges, each paired with surface ablation stake. Seven...
The sub-kilometre scale distribution of snow depth on Arctic sea ice impacts atmosphere-ice fluxes energy and mass, is importance for satellite estimates thickness from both radar lidar altimeters. While information about the mean this increasingly available modelling remote sensing, full cannot yet be resolved. We analyse 33539 measurements 499 transects taken at Soviet drifting stations between 1955 1991 derive a simple statistical over multi-year as function only depth. then evaluate...
It is well known that the snow type can affect mechanical behavior during slow compression, which may indicate fundamental differences in deformation mechanisms. To examine these differences, we performed consecutive loading-relaxation tests on three different types (rounded grains, depth hoar, and faceted crystals) at same strain rate of approximately 10-6 s-1 using a micro-compression stage allowed for X-ray tomography imaging before after experiment. By cycles, were able to eliminate...