A5048386608- Cryospheric studies and observations
- Winter Sports Injuries and Performance
- Arctic and Antarctic ice dynamics
- Landslides and related hazards
- Climate change and permafrost
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Geophysics and Gravity Measurements
- Polar Research and Ecology
- Oceanographic and Atmospheric Processes
- Planetary Science and Exploration
- Meteorological Phenomena and Simulations
- Spacecraft Design and Technology
- Aerospace Engineering and Energy Systems
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Geological Studies and Exploration
- Seismic Waves and Analysis
- Atmospheric and Environmental Gas Dynamics
- Arctic and Russian Policy Studies
- Complex Systems and Time Series Analysis
- Metallurgy and Material Forming
- Geophysical Methods and Applications
- Geotechnical and Geomechanical Engineering
- Soil Moisture and Remote Sensing
- Geological Modeling and Analysis
Jet Propulsion Laboratory
2016-2025
Oceanography Society
2016
California Institute of Technology
2011-2014
University of Cambridge
2001-2004
Université Libre de Bruxelles
1998-2001
Royal Meteorological Institute of Belgium
2001
Abstract The Amundsen Sea sector is experiencing the largest mass loss, glacier acceleration, and grounding line retreat in Antarctica. Enhanced intrusion of Circumpolar Deep Water onto continental shelf has been proposed as primary forcing mechanism for retreat. Here we investigate dynamics evolution Thwaites Glacier with a novel, fully coupled, ice‐ocean numerical model. We obtain significantly improved agreement observed pattern glacial using coupled Coupled simulations over coming...
Shrinking shelf and faster flow Zachariæ Isstrøm, a large glacier in northeast Greenland, began rapid retreat after detaching from stabilizing sill the late 1990s. Mouginot et al. report that between 2002 2014, area covered by glacier's ice shrank 95%; since 1999, rate has nearly doubled; its acceleration increased threefold fall of 2012. These dramatic changes appear to be result combination warmer air ocean temperatures topography floor at head glacier. Rising sea levels should continue...
Abstract Observations show that the Greenland ice sheet has been losing mass at an increasing rate over past few decades, which makes it a major contributor to sea-level rise. Here we use three-dimensional higher-order ice-flow model, adaptive mesh refinement and inverse methods accurately reproduce present-day flow of sheet. We investigate effect thermal regime on (1) basal sliding inversion (2) projections next 100 years. steady-state temperatures based conditions allow reasonable...
Calving is a primary process of mass ablation for glaciers and ice sheets, though it still eludes general physical law. Here, we propose calving framework based on continuum damage mechanics coupled with the equations viscous deformation glacier ice. We introduce scalar variable that quantifies loss load‐bearing surface area due to fractures feeds back viscosity represent fracture‐induced softening. The law standard failure criterion damaging materials represents macroscopic brittle...
Abstract. Modeling of grounding line migration is essential to accurately simulate the behavior marine ice sheets and investigate their stability. Here, we assess sensitivity numerical models parameterization position. We run MISMIP3D benchmark experiments using Ice Sheet System Model (ISSM) a two-dimensional shelfy-stream approximation (SSA) model with different mesh resolutions sub-element parameterizations Results show that lead steady state positions as well retreat/advance rates. Our...
Abstract We employ Sentinel‐1a C band satellite radar interferometry data in Terrain Observation with Progressive Scans mode to map the grounding line and ice velocity of Pope, Smith, Kohler glaciers, West Antarctica, for years 2014–2016 compare results those obtained using Earth Remote Sensing Satellites (ERS‐1/2) 1992, 1996, 2011. observe an ongoing, rapid retreat Smith at 2 km/yr (40 km since 1996), 11 Pope (0.5 km/yr), a readvance The variability glacier is consistent distribution basal...
Melting of the Greenland Ice Sheet represents a major uncertainty in projecting future rates global sea level rise. Much this is related to lack knowledge about subsurface oc ...
Abstract. Pine Island Glacier, a major contributor to sea level rise in West Antarctica, has been undergoing significant changes over the last few decades. Here, we employ three-dimensional, higher-order model simulate its evolution next 50 yr response surface mass balance, position of calving front and ocean-induced ice shelf melting. Simulations show that largest climatic impact on dynamics is rate melting, which rapidly affects glacier speed several hundreds kilometers upstream grounding...
Enhanced submarine ice-shelf melting strongly controls ice loss in the Amundsen Sea embayment (ASE) of West Antarctica, but its magnitude is not well known critical grounding zones ASE's major glaciers. Here we directly quantify bottom losses along tens kilometres with airborne radar sounding Dotson and Crosson shelves, which buttress rapidly changing Smith, Pope Kohler Melting found to be much higher than steady-state levels, removing 300–490 m solid between 2002 2009 beneath retreating...
Abstract The increasing contribution of the Antarctic Ice Sheet to sea level rise is linked reductions in ice shelf buttressing, driven large part by basal melting shelves. These ocean‐driven buttressing losses are being compounded as shelves weaken and fracture. To date, model projections sheet evolution have not accounted for weakening Here we present first constitutive framework deformation that explicitly includes mechanical weakening, based on observations progressive degradation...
Abstract. We present a new data assimilation method within the Ice Sheet System Model (ISSM) framework that is capable of assimilating surface altimetry from missions such as ICESat (Ice Cloud and land Elevation Satellite) into reconstructions transient ice flow. The relies on algorithmic differentiation to compute gradients objective functions with respect model forcings. It applied Northeast Greenland Stream, where mass balance basal friction forcings are temporally inverted, resulting in...
A new, complete velocity field from satellite remote sensing is combined with numerical modeling to infer the rheology of Larsen B Ice Shelf before its disintegration. The resulting spatial distribution flow parameter exhibits large variability, which reflects very well observed ice shelf features. This variability explained by factors including advection colder tributary glaciers, bottom melting, and presence zones strong shear fracture. inferred applied simulate numerically regime examine...
Marine ice, sometimes as part of an ice mélange, significantly affects shelf flow and fracture. The highly heterogeneous structure the Brunt/Stancomb‐Wills Ice Shelf (BSW) system in east Weddell Sea offers a rare setting for uncovering difference rheology between meteoric marine ice. Here, we use data assimilation to infer by inverse control method that combines interferometric synthetic aperture radar measurements with numerical modeling. We then apply inferred support hypothesis...
The disintegration of several Antarctic Peninsula ice shelves has focused attention on the state Larsen C Ice Shelf. Here, we use satellite observations to map shelf speed from years 2000, 2006 and 2008 apply inverse modeling examine spatial pattern ice‐shelf stiffness. Results show that northern half been accelerating since speeding up by 15% between 2000 alone. distribution stiffness exhibits large variations link tributary glacier flow fractures. Our results reveal down‐flow promontories...
Large rifts that open in Antarctic ice shelves are known to be filled by snow accumulations, shelf fragments, and sea ice. This work demonstrates how these may also from below, through their interaction with ocean water, marine The model presented here quantifies both the rate of accumulation at top rift, which results melt‐driven convection its sides, impact this process on waters occupying confined environment rift. show such a system could fill rift tens meters In temperature salinity...
Abstract In response to the 2017 Decadal Survey, NASA conducted a five‐year study on Surface Deformation and Change (SDC) designated observable potential mission concepts. As part of SDC study, Commercial Synthetic Aperture Radar (ComSAR) subgroup was tasked with evaluating current landscape SAR interferometric (InSAR) industry assess whether could leverage commercial smallsat products meet needs science mission. The assessment found that although is growing rapidly, off‐the‐shelf can...
Abstract In recent decades, the Greenland ice sheet has been losing and contributing substantially to global sea level rise. Approximately half of this loss is due glacier acceleration, increasing calving icebergs into ocean. This process linked with increased ocean heat content on continental shelf, yet pathways delivering Greenland's fjords its interactions fjord‐scale processes modulating are still unclear. study, we use a series numerical model configurations examine feedbacks between...
Abstract. Determining the future evolution of Antarctic Ice Sheet is critical for understanding and narrowing large existing uncertainties in century-scale global mean sea-level-rise (SLR) projections. One most significant glaciers ice streams Antarctica, Thwaites Glacier, at risk destabilization and, if destabilized, has potential to be largest regional-scale contributor SLR on Earth. This because Glacier vulnerable marine ice-sheet instability as its grounding line significantly influenced...
Abstract. Modeling of grounding line migration is essential to simulate accurately the behavior marine ice sheets and investigate their stability. Here, we assess sensitivity numerical models parameterization position. We run MISMIP3D benchmark experiments using a two-dimensional shelfy-stream approximation (SSA) model with different mesh resolutions sub-element parameterizations Results show that lead steady state positions as well retreat/advance rates. Our simulations explain why some...
Abstract High-resolution crystallographic, salinity and isotopic analyses of a 45 m ice core reveal the presence thick layer marine near grounding line Nansen Ice Shelf, Antarctica. The anomalous formation in zone assumed to be site active basal melting leads us propose hypothesis large crevasses as favorable environment for important marine-ice accretion. This hitherto unexplored possibility is supported by overall field configuration discrepancy some properties between this sections...
Abstract Ice shelves play a major role in buttressing ice sheet flow into the ocean, hence importance of accurate numerical modeling their stress regime. Commonly used models assume continuous medium and are therefore complicated by presence rupture features (crevasses, rifts, faults) that significantly affect overall patterns. Here we apply contact mechanics penalty methods to develop new shelf model captures impact rifts faults on rheology distribution shelves. The achieves best fit...
The innovations in high-performance, low-power electronics and low-cost space access are unlocking affordable distributed radar systems new remote sensing opportunities. Distributed Element Beamformer Radar for Ice Subsurface sounding (DEBRIS) is a concept to implement 2D sparse aperture improve the radar's spatial resolution investigation depth through reduction of surface clutter. Here, we introduce this system highlight its applications, orbital configurations, implementation...