A5028322779- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Meteorological Phenomena and Simulations
- Climate change and permafrost
- Oceanographic and Atmospheric Processes
- Climate variability and models
- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Marine animal studies overview
- Marine and environmental studies
- Freezing and Crystallization Processes
- Geophysics and Gravity Measurements
- Geology and Paleoclimatology Research
- Plant Water Relations and Carbon Dynamics
- Arctic and Russian Policy Studies
- Soil Moisture and Remote Sensing
- Atmospheric aerosols and clouds
- Food Industry and Aquatic Biology
- Tropical and Extratropical Cyclones Research
- Geological Studies and Exploration
- Precipitation Measurement and Analysis
- Ocean Waves and Remote Sensing
- Wind and Air Flow Studies
- Hydrology and Drought Analysis
- Winter Sports Injuries and Performance
Universität Trier
2016-2025
University of Bonn
1996-2007
The University of Melbourne
1996
British Antarctic Survey
1996
With the Arctic rapidly changing, needs to observe, understand, and model changes are essential. To support these needs, an annual cycle of observations atmospheric properties, processes, interactions were made while drifting with sea ice across central during Multidisciplinary Observatory for Study Climate (MOSAiC) expedition from October 2019 September 2020. An international team designed implemented comprehensive program document characterize all aspects system in unprecedented detail,...
Verification of two months, April and May 1997, 48-h mesoscale model simulations the atmospheric state around Greenland are presented. The performed with a modified version Pennsylvania State University–National Center for Atmospheric Research fifth-generation Mesoscale Model (MM5), referred to as Polar MM5. Global analyses well automatic weather station instrumented aircraft observations from used verify forecast state. is found reproduce observed high degree realism. Monthly mean values...
Abstract We examined 3 years of measured daily values all major water budget components (precipitation P , potential evapotranspiration PET actual ET and runoff R ) volumetric soil content θ a small, forested catchment located in the west Germany. The spatial distribution was determined from wireless sensor network 109 points with measurement depths each; calculated eddy‐covariance tower measurements. dominantly energy limited, amounting to approximately 90% ratio R/P 56%. closed long‐term...
The presence of sea-ice leads represents a key feature the Arctic sea ice cover. Leads promote flux sensible and latent heat from ocean to cold winter atmosphere are thereby crucial for air-sea-ice-ocean interactions. We here apply binary segmentation procedure identify MODIS thermal infrared imagery on daily time scale. method separates identified into two uncertainty categories, with high being attributed artifacts that arise warm signatures unrecognized clouds. Based obtained lead...
The presence of sea ice leads in the cover represents a key feature polar regions by controlling heat exchange between relatively warm ocean and cold atmosphere due to increased fluxes turbulent sensible latent heat. Sea contribute production are sources for formation dense water which affects circulation. Atmospheric models strongly rely on observational data describe respective state since numerical not able produce explicitly. For Arctic, some lead datasets available, but Antarctic, no...
Abstract Polynyas and leads are key elements of the wintertime Arctic sea-ice cover. They play a crucial role in surface heat loss, potential ice formation consequently seasonal budget. While polynyas generally sufficiently large to be observed with passive microwave satellite sensors, monitoring narrow requires use data at higher spatial resolution. We apply evaluate different lead segmentation techniques based on temperatures as measured by Moderate Resolution Imaging Spectroradiometer...
Abstract. Based upon thermal-infrared satellite imagery in combination with ERA-Interim atmospheric reanalysis data, we derive long-term polynya characteristics such as area, thin-ice thickness distribution, and ice-production rates for a 13-year investigation period (2002–2014) the austral winter (1 April to 30 September) Antarctic southern Weddell Sea. All parameters are derived from daily cloud-cover corrected composites. The focus lies on coastal polynyas which important hot spots...
ABSTRACT Quantile mapping (QM) is routinely applied in many climate change impact studies for the bias correction (BC) of daily precipitation data. It corrects complete distribution, but does not correct errors annual cycle. Therefore, QM often separately to temporal subsamples data (e.g. each calendar month), which reduces calibration sample size. The question arises whether this size reduction negates benefit from applying subsamples. We four methods a cross‐validation approach 40 years 10...
Abstract A coordinated regional climate model (RCM) evaluation and intercomparison project based on observations from a July–October 2014 trans‐Arctic Ocean field experiment (ACSE‐Arctic Clouds during Summer Experiment) is presented. Six state‐of‐the‐art RCMs were constrained with common reanalysis lateral boundary forcing upper troposphere nudging techniques to explore how the represented evolution of surface energy budget (SEB) components their relation cloud properties. We find that main...
Drought and heat events, such as the 2018 European drought, interact with exchange of energy between land surface atmosphere, potentially affecting albedo, sensible latent fluxes, well CO2 exchange. Each these quantities may aggravate or mitigate heat, their side effects on productivity, water scarcity global warming. We used measurements 56 eddy covariance sites across Europe to examine response fluxes extreme drought prevailing most year how differed various ecosystem types (forests,...
Abstract The ability of state‐of‐the‐art regional climate models to simulate cyclone activity in the Arctic is assessed based on an ensemble 13 simulations from 11 Arctic‐CORDEX initiative. Some employ large‐scale spectral nudging techniques. Cyclone characteristics simulated by are compared with results forced four reanalyses (ERA‐Interim, National Centers for Environmental Prediction‐Climate Forecast System Reanalysis, Aeronautics and Space Administration‐Modern‐Era Retrospective analysis...
Abstract. High-resolution MODIS thermal infrared satellite data are used to infer spatial and temporal characteristics of 17 prominent coastal polynya regions over the entire Arctic basin. Thin-ice thickness (TIT) distributions (≤ 20 cm) calculated from ice-surface temperatures, combined with ECMWF ERA-Interim atmospheric reanalysis in an energy balance model for 13 winter seasons (2002/2003 2014/2015; November March). From all available swath data, daily thin-ice composites computed order...
Abstract The presence of clouds in the Arctic regulates surface energy budget (SEB) over sea‐ice and ice‐free ocean. Following several previous field campaigns, cloud‐radiation relationship, including cloud vertical structure phase, has been elucidated; however, modeling this relationship matured slowly. In recognition recent decline extent, representation system numerical models should consider effects areas covered by sea ice areas. Using an situ stationary meteorological observation data...
Abstract Precise knowledge of wintertime sea ice production in Arctic polynyas is not only required to enhance our understanding atmosphere‐sea ice‐ocean interactions but also verify frequently utilized climate and ocean models. Here, a high‐resolution (2‐km) Moderate Resolution Imaging Spectroradiometer (MODIS) thermal infrared satellite data set featuring spatial temporal characteristics 17 polynya regions for the winter seasons 2002/2003 2017/2018 directly compared an akin low‐resolution...
Abstract. We use a novel sea-ice lead climatology for the winters of 2002/03 to 2020/21 based on satellite observations with 1 km2 spatial resolution identify predominant patterns in Arctic wintertime leads. The causes observed and temporal variabilities are investigated using ocean surface current velocities eddy kinetic energies from an model (Finite Element Sea Ice–Ice-Shelf–Ocean Model, FESOM) winds regional climate (CCLM) ERA5 reanalysis, respectively. presented investigation provides...
Low-level jets (LLJs) are important features in the Arctic atmospheric boundary layer (ABL). In present paper, a LLJ event during winter 2014/15 is investigated, which was observed at Tiksi observatory (71.586° N, 128.918° E, 7 m asl) Laptev Sea region. Besides routine synoptic observations, data from meteorological tower and SODAR/RASS (sound detection ranging/radio acoustic sounding system) were available. The latter yielded vertical profiles of wind temperature ABL with resolution 10...
Abstract. Sea-ice leads play a key role in the climate system by facilitating heat and moisture exchanges between ocean atmosphere, as well providing essential habitats for marine life. This study presents new dataset on monthly sea-ice Southern Ocean first comprehensive analysis of spatial patterns, seasonal variability, long-term trends wintertime (April to September) over 21-year period (2003–2023). Our findings reveal that are ubiquitous show distinct patterns with maximum lead...
This paper examines the role of Arctic Ocean Atlantic water (AW) in modifying Laptev Sea shelf bottom hydrography on basis historical records from 1932 to 2008, field observations carried out April–May and 2002–2009 cross‐slope measurements. A climatology demonstrates warming that extends offshore 30–50 m depth contour. Bottom layer temperature‐time series constructed links outer AW boundary current transporting warm saline North Atlantic. The mid‐1990s mid‐2000s is consistent with...
Polynyas in the Laptev Sea are examined with respect to recurrence and interannual wintertime ice production.We use a polynya classification method based on passive microwave satellite data derive daily area from long-term sea-ice concentrations. This provides insight into spatial temporal variability of open-water thin-ice regions Shelf. Using thermal infrared an empirical distribution within thickness range 0 20 cm, we calculate average surface heat loss resulting formation polynyas...
Considering the sea ice decline in Arctic during last decades, polynyas are of high research interest since these features core areas new formation. The determination formation requires accurate retrieval polynya area and thin-ice thickness (TIT) distribution within polynya. We use an established energy balance model to derive TITs with MODIS surface temperatures ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</i> <sub...
Abstract Basal melt of ice shelves may lead to an accumulation disc-shaped platelets underneath nearby sea ice, form a sub-ice platelet layer. Here we present the seasonal cycle attached Ekström Ice Shelf, Antarctica, and underlying layer in 2012. emerged from cavity interacted with fast-ice cover Atka Bay as early June. Episodic accumulations throughout winter spring led average platelet-layer thickness 4 m by December 2012, local maxima up 10 m. The additional buoyancy partly prevented...
The chytrid fungus Batrachochytrium salamandrivorans (Bsal) is a dangerous pathogen to salamanders and newts. Apparently native Asia, it has recently been detected in Western Europe where expected spread have dramatic effects on naïve hosts. Since 2010, Bsal led some catastrophic population declines of urodeles the Netherlands Belgium. More recently, discovered additional, more distant sites including Germany. With purpose contribute better understanding Bsal, we modelled its potential...
The regional climate model COSMO in Climate Limited-Area Mode (COSMO-CLM or CCLM) is used with a high resolution of 15 km for the entire Arctic all winters 2002/03–2014/15. simulations show spatial and temporal variability recent 2-m air temperature increase Arctic. maximum warming occurs north Novaya Zemlya Kara Sea Barents between March 2003 2012 responsible up to 20°C increase. Land-based observations confirm but do not cover regions that are located over ocean sea ice. Also, 30-km...