A5010845968- Cryospheric studies and observations
- Climate change and permafrost
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Winter Sports Injuries and Performance
- Landslides and related hazards
- Climate variability and models
- Methane Hydrates and Related Phenomena
- Geological Studies and Exploration
- Groundwater and Isotope Geochemistry
- Geophysics and Gravity Measurements
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Geological formations and processes
- Species Distribution and Climate Change
- Planetary Science and Exploration
- Polar Research and Ecology
- Pleistocene-Era Hominins and Archaeology
- Oceanographic and Atmospheric Processes
- Hydrology and Watershed Management Studies
- Smart Materials for Construction
- Geomagnetism and Paleomagnetism Studies
- Indigenous Studies and Ecology
- Marine animal studies overview
- Tree Root and Stability Studies
University of Calgary
2016-2025
Environment and Climate Change Canada
2020-2024
Mount Royal University
2014
Canadian Institute for Advanced Research
2007-2013
NSF NCAR Climate and Global Dynamics Laboratory
2006
NSF National Center for Atmospheric Research
2006
University of Arizona
2006
Institute of Arctic and Alpine Research
2006
University of Colorado Boulder
2006
University of British Columbia
1996-2000
In the future, Arctic warming and melting of polar glaciers will be considerable, but magnitude both is uncertain. We used a global climate model, dynamic ice sheet paleoclimatic data to evaluate Northern Hemisphere high-latitude its impact on icefields during Last Interglaciation. Our simulated matches observations past warming, combination physically based ice-sheet modeling with ice-core constraints indicate that Greenland Ice Sheet other circum-Arctic fields likely contributed 2.2 3.4...
Large millennial-scale fluctuations of the southern margin North American Laurentide Ice Sheet occurred during last deglaciation, when was located between about 43 degrees and 49 N. Fluctuations ice triggered episodic increases in flux freshwater to Atlantic by rerouting continental runoff from Mississippi River drainage Hudson or St. Lawrence Rivers. We found that periods increased flow at same time as reductions formation Deep Water, thus providing a mechanism for observed climate...
Abstract This paper discusses results from the second phase of European Ice Sheet Modelling Initiative (EISMINT). It reports intercomparison ten operational ice-sheet models and uses a series experiments to examine implications thermomechanical coupling for model behaviour. A schematic, circular ice sheet is used in work which investigates both steady states response stepped changes climate. The major finding that radial symmetry implied experimental design can, under certain circumstances,...
Current understanding of Pleistocene ice-sheet history is based on collective inferences from three separate avenues study: (1) the geologic and paleoceanographic records, (2) isostatic record, (3) behaviour contemporary glaciers ice sheets. The record provides good constraint areal extent former sheets, while deflection patterns provide important information about late-glacial thickness. picture emerging deductions suggestive a thin mobile Laurentide Ice Sheet relative to present-day...
Abstract Distributed glacier surface melt models are often forced using air temperature fields that either downscaled from climate or reanalysis, extrapolated station measurements. Typically, the downscaling and/or extrapolation performed a constant lapse rate, which is taken to be free-air moist adiabatic rate (MALR: 6°–7°C km−1). To explore validity of this approach, authors examined altitudinal gradients in daily mean along six transects across four glaciers Canadian high Arctic. The...
Abstract Screen temperatures were monitored from May 2001 to April 2003 in an array of 25 sites on the Prince Wales Icefield, Ellesmere Island, Canada. The observational network covered area ca 15 650 km 2 and spanned altitude ranging 130 2010 m above sea level. spatial provides a record near‐surface‐temperature lapse rates mesoscale temperature variability icefield. mean daily rate 2‐year is − 4.1° C −1 , with average summer 4.3° . Surface‐temperature region are therefore systematically...
Abstract Maps of glacier area in western Canada have recently been generated for 1985 and 2005 (Bolch et al., 2010), providing the first complete inventory cover Alberta British Columbia. Western lost about 11% its over this period, with loss exceeding 20% on eastern slopes Canadian Rockies. Glacier is difficult to relate volume, which attribute relevance water resources global sea level rise. We apply several possible volume-area scaling relations slope-thickness estimate volume ice...
Abstract. Perennial snow, or firn, covers 80 % of the Greenland ice sheet and has capacity to retain surface meltwater, influencing mass balance contribution sea-level rise. Multilayer firn models are traditionally used simulate processes estimate meltwater retention. We present, intercompare evaluate outputs from nine at four sites that represent sheet's dry percolation, slab aquifer areas. The forced by energy fluxes derived automatic weather stations compared density, temperature...
To address the ongoing global biodiversity crisis, conservation approaches must be underpinned by robust information. Canada is uniquely positioned to contribute meeting targets, with some of world's largest remaining intact ecosystems, and a commitment co-application Indigenous ways knowing alongside scientific, socioeconomic, other approaches. We elicited input from experts across range disciplines identify key information needed advance policy management actions conserve in Canada....
Episodic exportations of ice‐rafted debris to the North Atlantic in late Pleistocene suggest quasiperiodic ice streaming or surging activity on northeastern margin Laurentide Ice Sheet. Much this efflux may originate from an stream issuing Hudson Strait and tapping into core regions Bay, Labrador, Foxe Basin. Applying continuum mixture theory outlined by Marshall Clarke [this issue], we model thermomechanical evolution Stream a three‐dimensional finite difference Our simulations focus...
We simulate three‐dimensional ice temperature fields to examine spatial‐temporal history of the subglacial thermal environment during last glacial cycle. Model results suggest that 60–80% Laurentide Ice Sheet was cold‐based (frozen bed) at LGM, and therefore unable undergo large‐scale basal flow. The fraction warm‐based increases significantly through ensuing deglaciation, with only 10–20% frozen bed by 8 kyr BP. This evolution, a function both climatic sheet history, could enable dynamical...
Ice Lubricant The Greenland and Antarctic ice sheets both possess hydrological systems that allow water accumulating from the melting of surface to be transported base sheet. If water, when it reaches ice-bedrock interface, is distributed over large areas, will lubricate rapid sheet flow toward sea. Bamber et al. (p. 997 ) report existence a large, 750-km-long subglacial canyon in northern Greenland, which may act as channel for transport basal meltwater margin thus influence overall dynamics.
Ice streams are fast flowing arteries which play a vital role in the dynamics and mass balance of present‐day ice sheets. Although not fully understood, flow intimately coupled with geologic, topographic, thermal, hydrologic conditions underlying bed. These difficult observables beneath contemporary sheets, hindering elucidation processes govern stream behavior. For past sheets problem is antithetic. Geologic evidence former exists, but spatial temporal histories uncertain; however, detailed...
We employ a continuum mixture framework to incorporate ice streams in three‐dimensional thermomechanical model of the Laurentide Ice Sheet. The mass is composed binary sheet ice, which deforms by viscous creep, and stream flows sliding and/or sediment deformation at bed. Dynamic thermal evolutions are solved for each component mixture, with coupling rules govern transfer between flow regimes. describe two different mechanisms: (1) creep exchange, nourishment inflow from surrounding sheet,...
The Northern Hemisphere ice sheets decayed rapidly during deglacial phases of the ice-age cycle, producing meltwater fluxes that may have been sufficient magnitude to perturb oceanic circulation. continental record ice-sheet history is more obscured growth and advance last great sheets, ca. 120,000–20,000 yr B.P., but cores tell high-amplitude, millennial-scale climate fluctuations prevailed throughout this period. These climatic excursions would provoked significant fluctuation margins...
We apply a coupled energy‐balance/ice‐sheet climate model in an investigation of northern hemisphere ice‐sheet advance and retreat over the last glacial cycle. When driven only by orbital insolation variations, predicts advances continents North America Eurasia that are good agreement with geological reconstructions terms timescale spatial positioning main ice masses. The forcing alone, however, is unable to induce observed rapid retreat, we conclude additional climatic feedbacks not...
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 continued use of the positive degree-day (PDD) method to predict ice-sheet melt is generally favoured over surface energy-balance methods partly due computational efficiency algorithm and requirement only one input variable (temperature). In this paper, we revisit some assumptions governing application PDD method. Using hourly temperature data from GC-Net network test assumption that monthly total (PDD M ) can be represented by a Gaussian distribution with fixed standard...
Abstract. Seasonal measurements of glacier mass balance provide insight into the relation between climate forcing and change. To evaluate feasibility using remotely sensed methods to assess seasonal balance, we completed tandem airborne laser scanning (ALS) surveys field-based glaciological over a 4-year period for six alpine glaciers that lie in Columbia Rocky Mountains, near headwaters River, British Columbia, Canada. We calculated annual geodetic coregistered late summer digital elevation...