A5091385436- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Planetary Science and Exploration
- Winter Sports Injuries and Performance
- Arctic and Antarctic ice dynamics
- Space Exploration and Technology
- Landslides and related hazards
- Climate change and permafrost
- Astro and Planetary Science
- Methane Hydrates and Related Phenomena
- Polar Research and Ecology
- Space Science and Extraterrestrial Life
- Icing and De-icing Technologies
- Scientific Research and Discoveries
- Geological Studies and Exploration
- Climate variability and models
- Geological and Geochemical Analysis
- Rangeland and Wildlife Management
- Oceanographic and Atmospheric Processes
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Geological formations and processes
- Radar Systems and Signal Processing
- Flood Risk Assessment and Management
- Spaceflight effects on biology
University of Washington
2015-2025
Earth and Space Research
2015-2025
Seattle University
2013-2023
University of Copenhagen
2012-2013
California Institute of Technology
2002
The most recent glacial to interglacial transition constitutes a remarkable natural experiment for learning how Earth's climate responds various forcings, including rise in atmospheric CO2 This has left direct thermal remnant the polar ice sheets, where exceptional purity and continual accumulation of permit analyses not possible other settings. For Antarctica, deglacial warming previously been constrained only by water isotopic composition cores, without an absolute thermometric assessment...
Abstract The Antarctic contribution to sea level is a balance between ice loss along the margin and accumulation in interior. Accumulation records for past few decades are noisy show inconsistent relationships with temperature. We investigate relationship temperature 31 ka using high‐resolution from West Ice Sheet (WAIS) Divide core Antarctica. Although glacial‐interglacial increases result high correlation moderate sensitivity full record, shows considerable variability through time 0–8...
Abstract Radar sounding is a powerful geophysical approach for characterizing the subsurface conditions of terrestrial and planetary ice masses at local to global scales. As result, wide array orbital, airborne, ground-based, in situ instruments, platforms data analysis approaches radioglaciology have been developed, applied or proposed. Terrestrially, airborne radar has used glaciology observe thickness, basal topography englacial layers five decades. More recently, also exploited estimate...
The spatial pattern of accumulation rate can be inferred from internal layers in glaciers and ice sheets. Non-dimensional analysis determines where finite strain neglected (‘shallow-layer approximation’) or approximated with a local one-dimensional flow model (‘local-layer approximation’), gradients along particle paths must included (‘deep layers’). We develop general geophysical inverse procedure to infer the steady-state flowband, using measured topography ice-sheet surface, bed ‘deep...
Glaciers and ice sheets play an active role in the climate system global hydrological cycle. The stability of continental must be better understood for assessments future sea level rise to uncover causes millennial‐scale variability that characterized last glacial period. Ice‐rafted debris (IRD) midlatitude oceans subpolar seas tells widespread calving icebergs from Northern Hemisphere during period, but climatic implications this IRD are unclear. Does sediment record indicate repeated...
Abstract The West Antarctic Ice Sheet Divide Core (WDC) provided a high‐resolution climate record from near the Ross‐Amundsen in Central Antarctica. In addition, radar‐detected internal layers vicinity of WDC site have been dated directly ice core to provide spatial variations age structure region. Using these two data sets together, we first infer Holocene accumulation‐rate history 9.2 kyr ice‐core timescale and then confirm that this is consistent with upstream site. Even though was...
Abstract Data from the South Pole ice core (SPC14) are used to constrain climate conditions and ice‐flow‐induced layer thinning for last 54,000 years. Empirical constraints obtained SPC14 gas timescales, calculate annual‐layer thickness gas‐ice age difference (Δage), high‐resolution measurements of water isotopes, water‐isotope diffusion length. Both Δage length depend on firn properties therefore contain information about past temperature snow‐accumulation rate. A statistical inverse...
Data from the Mars Orbiter Laser Altimeter (MOLA) and Camera (MOC) instruments aboard Global Surveyor (MGS) were used in a detailed search of selected part South Polar Layered Deposits (SPLD) for impact craters. Impact craters with diameters 0.8 to 5 km identified MOLA‐derived shaded relief map primarily validated using individual MOLA tracks and, select cases, MOC narrow angle images. The resultant crater population determined this study is at least four times density previously recognized....
Abstract The South Pole Ice Core (SPICEcore) was drilled at least 180 km from an ice‐flow divide. Thus, the annual‐equivalent layer thicknesses in core are affected by spatial variations accumulation upstream addition to temporal regional accumulation. We use a new method compare SPICEcore record, derived correcting measured for thinning, with record GPS and radar measurements upstream. When ice speeds modeled as increasing 15% since 10 ka, explains 77% of variance SPICEcore‐derived (versus...
Abstract Using radar data from the Beardmore Glacier grounding zone, we image a narrow subglacial channel ( m wide) that reaches height of 200 above ambient ice‐shelf draft. repeat ICESat‐2 observations and Worldview digital elevation models, show this observe with is part system channels. These channels form near zone where axis runs up‐gradient in smoothed ice base (perpendicular to contours). Downstream, these features are advected flow expressed as Eulerian surface change differenced...
ABSTRACT The widespread retreat of mountain glaciers is a striking emblem recent climate change. Yet mass-balance observations indicate that many are out equilibrium with current climate, meaning observed retreats do not show the full response to warming. This fundamental consequence glacier dynamics: typically have multidecadal timescales, and so their lags centennial-scale trends. A substantial difference between transient length persists throughout warming period; we refer this as...
Abstract Observations of snow accumulation rates from five new firn cores show a negative trend that is statistically significant over the past several decades across central West Antarctic ice sheet (WAIS). A temporal in unexpected light rising surface temperatures as well model simulations predicting higher for region. Both magnitude mean and range interannual variability observed records compare favorably to older collected broad area WAIS, suggesting data may serve regional proxy recent...
Abstract. The South Pole Ice Core (SPICEcore), which spans the past 54 300 years, was drilled far from an ice divide such that recovered at depth originated upstream of core site. If climate is different upstream, history will be a combination conditions advected to site and temporal changes. Here, we evaluate impact advection on two fundamental records SPICEcore: accumulation rate water isotopes. We determined locations deposition based GPS measurements modern velocity field spanning 100 km...
Abstract Accumulation rates and their spatio-temporal variability are important boundary conditions for ice-flow models. The depths of radar-detected internal layers can be used to infer the spatial accumulation rates. Here we from three radar (26, 35 41 ka old) in Vostok Subglacial Lake region using two methods: (1) local-layer approximation (LLA) (2) a combination steady-state flowband modeling formal inverse methods. LLA assumes that strain-rate history particle traveling through ice...
Abstract. The dynamics of marine-terminating outlet glaciers are fundamental interest in glaciology and affect mass loss from ice sheets a warming climate. In this study, we analyze the response to different sources climate forcing. We find that have characteristically transient surface-mass-balance forcing applied over interior than oceanic at grounding line. A recently developed reduced model represents outlet-glacier via two widely separated timescales: fast associated with grounding-zone...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Journal of Geophysical Research - Atmospheres. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing an older version [v2]Go new versionReconstruction temperature, accumulation rate, layer thinning from ice core South Pole using statistical inverse methodAuthorsEmma C.KahleEric J.SteigiDTyler...
Abstract The mean, trend and variability of net snow accumulation in firn cores are often used to validate model output, develop remote-sensing algorithms quantify ice-sheet surface mass balance. Thus, accurately defining uncertainties associated with these situ measurements is critical. In this study, we apply statistical simulation methods the uncertainty firn-core data due depth–age scales. applied a suite from central West Antarctica. results show that scales can give rise spurious...
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...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Journal of Geophysical Research - Atmospheres. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v3]Reconstruction temperature, accumulation rate, layer thinning from an ice core South Pole using statistical inverse methodAuthorsEmma C.KahleEric...