A5026833215- Cryospheric studies and observations
- Geophysics and Gravity Measurements
- Winter Sports Injuries and Performance
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Landslides and related hazards
- earthquake and tectonic studies
- Arctic and Antarctic ice dynamics
- Geomagnetism and Paleomagnetism Studies
- Climate change and permafrost
- GNSS positioning and interference
- High-pressure geophysics and materials
- Climate variability and models
- Inertial Sensor and Navigation
- Oceanographic and Atmospheric Processes
- Geological and Geophysical Studies
- Geophysical and Geoelectrical Methods
- Geological Modeling and Analysis
- Geological and Geochemical Analysis
- 3D Modeling in Geospatial Applications
- Planetary Science and Exploration
- Geographic Information Systems Studies
- Atmospheric and Environmental Gas Dynamics
- Coastal and Marine Management
- Geological formations and processes
Technical University of Denmark
2013-2024
DTU Space
2011-2024
Space (Italy)
2021
The Ohio State University
2015-2018
University of Iceland
2017
Danish Geodata Agency
2011-2013
University of Milan
2006-2011
The Abdus Salam International Centre for Theoretical Physics (ICTP)
2011
We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, models surface mass balance glacial isostatic adjustment to estimate the Earth's polar ice sheets. find that there is good agreement between different methods--especially in Greenland West Antarctica--and combining leads greater certainty. Between 1992 2011, sheets Greenland, East Antarctica, Antarctic Peninsula changed by -142 ± 49, +14 43, -65 26, -20...
Abstract. Global mean sea level is an integral of changes occurring in the climate system response to unforced variability as well natural and anthropogenic forcing factors. Its temporal evolution allows (e.g., acceleration) be detected one or more components. Study sea-level budget provides constraints on missing poorly known contributions, such unsurveyed deep ocean still uncertain land water component. In context World Climate Research Programme Grand Challenge entitled Regional Sea Level...
The marine portion of the West Antarctic Ice Sheet (WAIS) in Amundsen Sea Embayment (ASE) accounts for one-fourth cryospheric contribution to global sea-level rise and is vulnerable catastrophic collapse. bedrock response ice mass loss, glacial isostatic adjustment (GIA), was thought occur on a time scale 10,000 years. We used new GPS measurements, which show rapid (41 millimeters per year) uplift ASE, estimate viscosity mantle underneath. found much lower (4 × 1018 pascal-second) than...
Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, invoking a solid Earth response that has been recorded at continuous GPS (cGPS) stations. A previous attempt to model observation of rapid uplift following 2002 breakup Larsen B Ice Shelf was limited by incomplete knowledge pattern unloading possibly assumption an elastic-only mechanism. We make use new high resolution dataset elevation change captures loss north 66°S first...
A R YThe study of glacial isostatic adjustment (GIA) is gaining an increasingly important role within the geophysical community.Understanding response Earth to loading crucial in various contexts, ranging from interpretation modern satellite geodetic measurements (e.g.GRACE and GOCE) projections future sea level trends climate change.Modern modelling approaches GIA are based on techniques that range purely analytical formulations fully numerical methods.Despite teams independently...
Abstract. During the last decade, GRACE mission has provided valuable data for determining mass changes of Greenland and Antarctic ice sheets. Yet, discrepancies still exist in published balance results, comprehensive analyses on sources errors are lacking. Here, we present monthly together with trends derived from at basin scale both sheets, assess variability each possible discrepancies, do this an unprecedented systematic way, taking into account inference methods, sets background models....
Abstract We present the first 1992–2020 record of Greenland Ice Sheet (GrIS) mass balance derived from multisatellite Ku‐band altimetry. employ an empirical approach as alternative detailed to radar‐propagation modeling, and instead convert elevation changes observed by radar altimetry into using spatiotemporal calibration fields. This field is a machine learning that optimizes prediction previously published function ice sheet variables. Our shows GrIS contribution 12.1 ± 2.3 mm sea‐level...
Abstract. Studies of the global sea-level budget (SLB) and ocean-mass (OMB) are essential to assess reliability our knowledge change its contributors. Here we present datasets for times series SLB OMB elements developed in framework ESA's Climate Change Initiative. We use these simultaneously, utilising a consistent uncertainty characterisation. The time series, given at monthly sampling available https://doi.org/10.5285/17c2ce31784048de93996275ee976fff (Horwath et al., 2021), include mean...
The Greenland ice sheet is a major contributor to sea level rise, adding on average 0.47 ± 0.23 mm year − 1 global mean between 1991 and 2015. cryosphere as whole has contributed around 45% of observed rise since 1993. Understanding the present-day state therefore vital for understanding processes controlling modern-day rates change making projections into future. Here, we provide an overview current mass budget based diverse range remote sensing observations produce essential climate...
Abstract The Greenland Ice Sheet is the largest land ice contributor to sea level rise. This will continue in future but at an uncertain rate and observational estimates are limited last few decades. Understanding long-term glacier response external forcing key improving projections. Here we use historical photographs calculate loss from 1880–2012 for Jakobshavn, Helheim, Kangerlussuaq glacier. We estimate corresponding a rise of 8.1 ± 1.1 millimetres these three glaciers. Projections mass...
Satellite gravimetry data acquired by the Gravity Recovery and Climate Experiment (GRACE) allows to derive temporal evolution in ice mass for both Antarctic Ice Sheet (AIS) Greenland (GIS). Various algorithms have been used a wide range of studies generate Gravimetric Mass Balance (GMB) products. Results from different may be affected substantial differences processing, including applied algorithm, utilised background models time period under consideration. This study gives detailed...
In Fennoscandia, tectonics, Glacial Isostatic Adjustment (GIA), and climatic changes cause ongoing crustal deformation of some millimetres per year, both vertically horizontally. These displacements the Earth can be measured to a high degree precision using Global Navigation Satellite System (GNSS). Since about three decades, this is major goal Baseline Inferences for Fennoscandian Rebound, Sea-level, Tectonics (BIFROST) project. We present new velocity field an extended BIFROST GNSS network...
Present day glacier reduction in the Alps, estimated from inventories and induced viscoelastic response of a stratified Earth's model, is responsible for sizable uplift rates. Patches 0.4–0.5 mm/yr, due to ice mass loss largest complexes, overprint characteristic area slower 0.1–0.2 signature phenomenon whole Alpine chain. Viscous stress relaxation lower crust, after end Little Ice Age, expected produce rates 0.32 leading total up 0.8 mm/yr. Our predictions western Alps show that present...
The ocean load in glacial isostatic adjustment (GIA) modelling is represented by the so-called sea level equation (SLE). SLE describes mass redistribution of water between ice sheets and oceans on a deforming Earth. Despite various teams independently investigating GIA, there has been no systematic intercomparison among numerical solvers through which methods may be validated. goal this paper to present series synthetic examples designed for testing comparing implementations GIA modelling....
Present-day global mean sea level evolution results from ocean thermal expansion as well changes of glaciers and ice sheets mass, in terrestrial water storage. It is considered an integrator occurring the climate system response to unforced variability natural anthropogenic forcing factors. Monitoring allows detecting (e.g., trend or acceleration) one more components. Closure budget implies that observed equal sum contributions. Mis-closure these balances indicates errors some components...
Abstract Accurate glacial isostatic adjustment (GIA) models are required for correcting measurements of mass change in Antarctica and improving knowledge the sub‐surface, especially areas large current ice loss such as Amundsen Sea Embayment (ASE). Regionally, seismic gravity data suggests lateral differences viscosity (3D). Furthermore, mantle flow laws allow a stress‐dependent effective which changes over time (3D‐s). In this study we investigate whether with 3D/3D‐s have significant...
In the context of global sea level rise and climate change related scale phenomena, Greenland mass balance (GMB) plays a crucial role. Estimates GMB are regularly updated, using three main methods. Those based mainly on satellite data: 1) gravity variations, e.g. GRACE, 2) surface elevation changes, CryoSat-2, IceSat-2 3) ice flow (input-output method) inferred from velocities.Each these methods has strengths weaknesses, they rely models assumptions to infer changes that cannot be measured...
Basal sliding is a key process that controls the ice discharge of into ocean. Understanding this essential for improving reliability future projections sheet evolution and sea level rise. The basal law, which governs ice-bed interactions, remains critical yet poorly understood in models. Recent advances transient calibration techniques, incorporate time series observed surface velocity elevation, have enhanced ability numerical models to infer conditions. However, relying on same type...
The surface elevation of the Greenland Ice Sheet undergoes continuous changes driven by interaction mass balance processes and ice dynamics, each displaying distinct spatial temporal characteristics. In this study, we utilize satellite airborne altimetry data with high (1 km) (monthly) resolution to examine these from January 2003 August 2023. Our analysis highlights complex evolving change patterns Jakobshavn Isbræ (JI). Specifically, document thinning near JI terminus 2015,...
The measurement of ongoing ice-mass loss and associated melt water contribution to sea-level change from regions such as West Antarctica is dependent on a combination remote sensing methods. A key method, the changes in Earth's gravity via GRACE satellite mission, requires potentially large correction account for isostatic response solid Earth ice-load since Last Glacial Maximum. In this study, we combine glacial adjustment modelling with new GPS dataset deformation southern Antarctic...
Redistribution of mass over the Earth and within mantle changes gravity field whose variations are monitored at high spatial resolution by presently flying GRACE space mission from NASA or, longer wavelengths, Satellite Laser Ranging (SLR) constellation. In principle, data allow one to study time evolution various phenomena through their gravitational effects. The correct identification temporal fingerprints individual hydrologic, atmospheric, oceanographic solid is thus extremely important,...
Abstract. The mass balance of glaciers and ice caps is sensitive to changing climate conditions. changes derived in this study are determined from elevation measured by the Ice, Cloud, land Elevation Satellite (ICESat) for time period 2003–2009. Four methods, based on interpolation extrapolation, used regionalize these areas without satellite coverage. A constant density assumption then applied estimate change integrating over entire glaciated region. main purpose investigate sensitivity...