A5004217613- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Geophysics and Gravity Measurements
- Oceanographic and Atmospheric Processes
- Icing and De-icing Technologies
- Climate variability and models
- Arctic and Russian Policy Studies
- Polar Research and Ecology
- Atmospheric aerosols and clouds
- Remote Sensing and LiDAR Applications
- Meteorological Phenomena and Simulations
- Geological Modeling and Analysis
- Atmospheric and Environmental Gas Dynamics
- Military Technology and Strategies
- Geography Education and Pedagogy
- Image Processing and 3D Reconstruction
- Isotope Analysis in Ecology
- Tree-ring climate responses
- Scientific Research and Discoveries
- Radioactive contamination and transfer
- Solar and Space Plasma Dynamics
- Planetary Science and Exploration
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2017-2025
University of Zurich
2018
University of Bremen
2017-2018
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...
Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic dynamic processes alter sea thickness. The Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition provided unique opportunity to study seasonal changes same ice. We analyzed 11 large-scale (∼50 km) airborne electromagnetic surface roughness surveys from October 2019 September 2020. Data mass balance position buoys additional information. found that thermodynamic growth decay...
Melt ponds on sea ice play an important role in the Arctic climate system. Their presence alters partitioning of solar radiation: decreasing reflection, increasing absorption and transmission to ocean, enhancing melt. The spatiotemporal properties melt thus modify albedo feedbacks mass balance ice. Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition presented a valuable opportunity investigate seasonal evolution through rich array atmosphere-ice-ocean measurements...
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. In September 2019, the research icebreaker Polarstern started largest multidisciplinary Arctic expedition to date, MOSAiC (Multidisciplinary drifting Observatory for Study of Climate) drift experiment. Being moored an ice floe a whole year, thus including winter season, declared goal is better understand and quantify relevant processes within atmosphere–ice–ocean system that impact sea mass energy budget, ultimately leading much improved climate models. Satellite observations,...
Abstract. We combine satellite data products to provide a first and general overview of the physical sea ice conditions along drift international Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) expedition comparison with previous years (2005–2006 2018–2019). find that MOSAiC was around 20 % faster than climatological mean drift, as consequence large-scale low-pressure anomalies prevailing Barents–Kara–Laptev region between January March. In winter (October–April),...
During the Arctic melt season, relatively fresh meltwater layers can accumulate under sea ice as a result of snow and melt, far from terrestrial freshwater inputs. Such under-ice layers, sometimes referred to ponds, have been suggested play role in summer mass balance both by isolating saltier water below, driving formation ‘false bottoms’ below ice. form at interface fresher layer colder, seawater below. Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition Central...
Abstract The Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition took place between October 2019 and September 2020 giving rare opportunity to monitor sea-ice properties over a full annual cycle. Here we present 24 high-resolution orthomosaics 14 photogrammetric digital elevation models surface around icebreaker RV Polarstern March 2020. dataset is based on >34.000 images acquired by helicopter-borne optical camera system with survey flights covering...
Abstract. Leads and fractures in sea ice play a crucial role the heat gas exchange between ocean atmosphere, impacting atmospheric, ecological, oceanic processes. We estimated lead fractions from high-resolution divergence obtained satellite synthetic aperture radar (SAR) data evaluated them against existing products. derived two new fraction products with spatial resolution of 700 m calculated daily Sentinel-1 images. For first product, we advected accumulated individual time instances....
Abstract. Changes in Arctic sea ice thickness are the result of complex interactions dynamic and variable cover with atmosphere ocean. Most exiting Ocean does so through Fram Strait, which is why long-term measurements at end Transpolar Drift provide insight into integrated signals thermodynamic influences along pathways ice. We present an updated summer (July–August) time series extensive surveys carried out between 2001 2020. Overall, we see a more than 20 % thinning modal since 2001. A...
Abstract. An unusual, large, latent-heat polynya opened and then closed by freezing convergence north of Greenland's coast in late winter 2018. The closing presented a natural but well-constrained full-scale ice deformation experiment. We observed the within with satellite synthetic-aperture radar (SAR) imagery measured accumulated effects dynamic thermodynamic growth an airborne electromagnetic (AEM) thickness survey 1 month after began. During that time, strong decreased area refrozen...
Abstract. Knowledge of sea-ice thickness and volume depends on freeboard observations from satellite altimeters in turn information snow mass density required for the freeboard-to-thickness conversion. These parameters, especially density, are usually based climatologies constructed situ made 1980s earlier while contemporary representative measurements lacking. Our aim with this paper is to derive updated bulk estimates suitable present Arctic cover a range ice types reduce uncertainties...
Abstract. Melt ponds are a core component of the summer sea ice system in Arctic, increasing uptake solar energy and impacting ice-associated ecosystem. They were thus one key topics during 1-year drift campaign Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) Transpolar Drift 2019/2020. Pond depth is dominating factor describing surface meltwater volume; it necessary to estimate budgets used model parameterization simulate pond coverage evolution. However,...
Arctic sea ice is a mosaic of floes whose distribution and thicknesses greatly impact the interaction with atmosphere ocean. However, we are still lacking knowledge physics to describe complex interplay that key characteristic ice. In our contribution, outline framework characterize sea-ice deformation at floe-scale from observational data by studying mechanical multiple identifiable floes. We use Sentinel SAR imagery ICESat-2 acquired during MOSAiC expedition map their thickness in larger...
Abstract Airborne laser scanners (ALS) are used to map the sea-ice surface at sub-meter resolution. We conducted 64 flights over Arctic sea ice between September 2019 and 2020 during Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition measure elevation. The ranged from repeated, local-scale 5 × km 2 floe grid surveys regional-scale transects more than 100 long. provide data different processing levels: geolocated elevation point clouds gridded segments freeboard...
Abstract Increased ocean‐to‐ice heat fluxes play a key role in the accelerated mass loss of Greenland’s marine‐terminating glaciers. Ocean current variability leads to variations this flux. A year‐long time series ocean currents at all gateways cavity under largest remaining floating ice tongue Nioghalvfjerdsfjorden Glacier (79NG) was analyzed. The exchange flow intra‐annual near‐daily timescales characterized. exhibit considerable with standard deviations exceeding mean strength by factor...
Abstract. Despite its relevance for the Arctic climate and ecosystem, modeling sea-ice deformation, i.e., opening, shearing, ridging of sea ice, along linear kinematic features (LKFs) remains challenging, as mechanical properties ice are not yet fully understood. The intersection angles between LKFs provide valuable information on internal properties, they linked to them. Currently, emerging from rheological models do reproduce observed LKF angles, pointing a gap in model physics. We aim...
Abstract The amount of snow on Arctic sea ice impacts the mass budget. Wind redistribution into open water in leads is hypothesized to cause significant wintertime loss. However, there are no direct measurements loss leads. We measured lost four Central winter 2020. find, contrary expectations, that under typical conditions, minimal was during a cyclone delivered warm air temperatures, high winds, and snowfall, 35.0 ± 1.1 cm equivalent (SWE) lead (per unit area). This corresponded removal...
Abstract. Leads and fractures in sea ice play a crucial role the heat gas exchange between ocean atmosphere, impacting atmospheric, ecological, oceanic processes. Our aim was to estimate lead fractions from high-resolution divergence obtained satellite synthetic-aperture radar (SAR) data evaluate it against existing products. We derived two new lead-fraction products with spatial resolution of 700 m calculated daily Sentinel-1 images. For first product, we advected accumulated individual...
If and how the sea ice cycle drives methane in high Arctic is an open question crucial to improving source/sink balances. This study presents new insights into effects of strong fast freezing on physical–chemical properties offers implications for fluxes out newly formed lead ice. During 2019–2020 transpolar drift Multidisciplinary Drifting Observatory Study Climate (MOSAiC), we took weekly samples growing underlying seawater at same site between January March 2020. We analyzed...
Abstract. To investigate the influence of sea ice openings like leads on wintertime Arctic clouds, air mass transport is exploited as a heat and humidity feeding mechanism which can modify cloud properties. Cloud microphysical properties in central are analysed function conditions during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition 2019–2020. The Cloudnet classification algorithm used to characterize clouds based remote sensing observations atmospheric...
Abstract. Knowledge of sea-ice thickness and volume depends on freeboard observations from satellite altimeters in turn information snow mass density required for the freeboard-to-thickness conversion. These parameters, especially density, are usually based climatologies constructed situ made 1980s before while contemporary representative measurements lacking. Our aim with this paper is to derive updated bulk estimates suitable present Arctic cover a range ice types reduce uncertainties...