A5087836361- Cryospheric studies and observations
- Winter Sports Injuries and Performance
- Landslides and related hazards
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Polar Research and Ecology
- Meteorological Phenomena and Simulations
- Climate change and permafrost
- Geological Studies and Exploration
- Geophysics and Gravity Measurements
- Plant Water Relations and Carbon Dynamics
- Adventure Sports and Sensation Seeking
- Clinical Nutrition and Gastroenterology
- Hydrological Forecasting Using AI
- Geological and Geophysical Studies Worldwide
- Geomagnetism and Paleomagnetism Studies
- Marine and environmental studies
- Forest Biomass Utilization and Management
- Methane Hydrates and Related Phenomena
- Planetary Science and Exploration
- Geological Formations and Processes Exploration
- Healthcare Systems and Challenges
- Metabolism and Genetic Disorders
- Geochemistry and Geologic Mapping
- Climate variability and models
Los Alamos National Laboratory
2020-2025
Earth and Space Research
2016-2021
University of Washington
2016-2021
Abstract The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) is the primary effort of (Coupled Project–Phase 6) focusing on ice sheets, designed to provide an ensemble process‐based projections ice‐sheet contribution sea‐level rise over twenty‐first century. However, behavior Antarctic beyond 2100 remains largely unknown: several instability mechanisms can develop longer time scales, potentially destabilizing large parts Antarctica. Projections evolution until 2300 are presented...
We describe glacial-geological observations and cosmogenic-nuclide exposure ages from the Schmidt, Williams, Thomas Hills in Pensacola Mountains of Antarctica adjacent to Foundation Ice Stream (FIS). Our aim is learn about changes thickness grounding line position Antarctic Sheet Weddell Sea embayment between Last Glacial Maximum (LGM) present. Glacial-geological all three regions indicate that currently-ice-free areas were covered by ice during one or more past sheet expansions, this was...
Viscoelastic rebound of the solid Earth upon removal ice loads has potential to inhibit marine sheet instability, thereby forestalling ice-sheet retreat and global mean sea-level rise. The timescale over which - system responds changes in thickness bedrock topography places a strong control on spatiotemporal influence this negative feedback mechanism. In study, we assess impact solid-earth rheological structure model projections Thwaites Glacier, West Antarctica, concomitant rise by coupling...
In fast-flowing regions of the Antarctic and Greenland ice sheets, most motion occurs through slip at boundary between its substrate. Glaciologists have developed “slip laws” that describe basal as a function resistive stress (e.g. drag) effective pressure. When implemented in sheet models, choice law affects predictions grounding-line migration sea-level rise. Slip laws models assume base glacier is “clean” (without rock debris) separated from bed by...
Representing ice-shelf and ocean interactions in Earth system models (ESMs) has been challenging due to their coarse resolution static ice shelf cavity geometries. Additionally, coupling techniques often struggle conserve mass energy across components. We have recently implemented new algorithms the component of Energy Exascale System Model enable dynamic ice-ocean within Antarctica’s cavities. These include a thin subglacial film below grounded ice, runoff into cavities,...
Abstract. This study investigated the computational benefits of using multi-fidelity statistical estimation (MFSE) algorithms to quantify uncertainty in mass change Humboldt Glacier, Greenland, between 2007 and 2100 a single climate scenario. The goal this was determine whether MFSE can use multiple models varying cost accuracy reduce estimating mean variance projected glacier. problem size complexity were chosen reflect challenges posed by future continental-scale studies while still...
Abstract. Mass loss from the West Antarctic Ice Sheet (WAIS) is increasing, and there concern that an incipient large-scale deglaciation of marine basins may already be underway. Measurements cosmogenic nuclides in subglacial bedrock surfaces have potential to establish whether when marine-based portions WAIS deglaciated past. However, because most revealed by ice-sheet collapse would remain below sea level, shielded cosmic-ray flux, drill sites for sampling must located areas where thinning...
Abstract. Antarctica's Lambert Glacier drains about one-sixth of the ice from East Antarctic Ice Sheet and is considered stable due to strong buttressing provided by Amery Shelf. While previous projections sea-level contribution this sector sheet have predicted significant mass loss only with near-complete removal shelf, ocean warming necessary for was deemed unlikely. Recent climate through 2300 indicate that sufficient a distinct possibility after 2100. This work explores impact parametric...
Abstract During the last glaciation, East Antarctic outlet glaciers contributed to a grounded ice sheet in Ross Embayment. The timing of maximum extent, as well subsequent deglaciation these outlets, has implications for behavior Ice Sheet (AIS) and its impact on global sea level. We present 45 radiocarbon ages lacustrine cyanobacteria from Lake Wellman region alongside Hatherton Glacier, which are first terrestrial data both record advance an glacier position document high-resolution...
Abstract. Chronologies of glacier deposits in the Transantarctic Mountains provide important constraints on grounding-line retreat during last deglaciation Ross Sea. However, between Beardmore Glacier and Island – a distance some 600 km existing chronologies are generally sparse far from modern grounding line, leaving past dynamics this vast region largely unconstrained. We present exposure ages glacial at three locations alongside Darwin–Hatherton System including within 10 line that record...
Abstract. Mass loss from the West Antarctic Ice Sheet (WAIS) is increasing, and there concern that an incipient large-scale deglaciation of marine basins may already be underway. Measurements cosmogenic nuclides in subglacial bedrock surfaces have potential to establish whether when marine-based portions WAIS deglaciated past. However, because most revealed by ice-sheet collapse would remain below sea level, shielded cosmic-ray flux, drill sites for sampling must located areas where thinning...
Abstract. Humboldt Glacier, northern Greenland, has retreated and accelerated through the 21st century, raising concerns that it could be a significant contributor to future sea-level rise. We use data-constrained ensemble of three-dimensional higher-order ice sheet model simulations estimate likely range rise from continued retreat Glacier. first solve for basal traction using observed thickness, bed topography, surface velocity year 2007 in PDE-constrained (partial differential equation)...
Abstract. Antarctica's Lambert Glacier drains about one-sixth of the ice from East Antarctica Ice Sheet and is considered stable due to strong buttressing provided by Amery Shelf. While previous projections sea-level contribution this sector sheet have predicted significant mass loss only with near complete removal shelf, ocean warming necessary for was deemed unlikely. Recent climate through 2300 indicate that sufficient a distinct possibility after 2100. This work explores impact...
We report geomorphic observations and cosmogenic-nuclide measurements on bedrock surfaces from three isolated nunatak groups in West Antarctica: the Pirrit Hills Nash Hills, located Weddell Sea sector, Whitmore Mountains, Ross-Weddell divide. The objectives of this paper are to (i) establish a chronology for landscape development at these sites (ii) quantify long-term history ice-thickness variations Antarctica. These nunataks display relic alpine landscapes which weathered superimposed. In...
Abstract Crary Ice Rise formed after the Ross Shelf re-grounded ~1 kyr BP. We present new ice-penetrating radar data from two systems operating at center frequencies of 7 and 750 MHz that confirm ice rise is composed a former shelf buried by subsequent accumulation. Stacks englacial diffraction hyperbolas are almost everywhere across central extend up to ~350 m above bed. In many cases, bed reflections beneath obscured for distances 1 km. Waveform modeling indicates likely caused marine...
Abstract. Humboldt Glacier, North Greenland, has retreated and accelerated through the 21st century, raising concerns that it could be a significant contributor to future sea-level rise. We use data-constrained ensemble of three-dimensional higher-order ice sheet model simulations estimate likely range rise from continued retreat Glacier. first solve for basal traction using observed thickness, bed topography, surface velocity year 2007 in partial differential equation constrained...
Projecting sea-level change in various climate-change scenarios typically involves running forward simulations of the Earth's gravitational, rotational and deformational (GRD) response to ice mass change, which requires high computational cost time. Here we build neural-network emulators at 27 coastal locations, due GRD effects associated with future Antarctic Ice Sheet over 21st century. The are based on datasets produced using a numerical solver for static equation published ISMIP6-2100...
Abstract. This study investigated the computational benefits of using multi-fidelity uncertainty quantification (MFUQ) algorithms to quantify in mass change Humboldt Glacier, Greenland, between 2007 and 2100 a single climate scenario. The goal this was determine whether MFUQ can use multiple models varying cost accuracy reduce estimating mean variance projected an ice sheet. problem size complexity were chosen be representative future continental scale studies while still facilitating...
Evolution of ice sheets contribute to sea-level change globally by exchanging mass with the ocean, and regionally causing solid Earth deformation perturbation Earth’s rotation gravitational field, so-called “gravitational, rotational deformational (GRD) effects”. In last decade, much work has been done establish importance coupling GRD effects particularly in modeling marine-based (e.g., West Antarctic Ice Sheet; WAIS) capture interactions between sheets, sea...