A5004633054- Cryospheric studies and observations
- Arctic and Antarctic ice dynamics
- Climate change and permafrost
- Geology and Paleoclimatology Research
- Landslides and related hazards
- Winter Sports Injuries and Performance
- Meteorological Phenomena and Simulations
- Methane Hydrates and Related Phenomena
- Icing and De-icing Technologies
- Remote Sensing and LiDAR Applications
- Polar Research and Ecology
- Mechanical Behavior of Composites
- Seismology and Earthquake Studies
- Geological Studies and Exploration
- Geophysics and Gravity Measurements
- Atmospheric chemistry and aerosols
- Textile materials and evaluations
- Fiber-reinforced polymer composites
- Climate variability and models
- Oceanographic and Atmospheric Processes
- Remote Sensing in Agriculture
- Atmospheric and Environmental Gas Dynamics
- Fire effects on ecosystems
- Species Distribution and Climate Change
- 3D Surveying and Cultural Heritage
Dartmouth College
2014-2024
Dartmouth Hospital
2014-2022
Year-round observations of the physical snow and ice properties processes that govern pack evolution its interaction with atmosphere ocean were conducted during Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) expedition research vessel Polarstern in Ocean from October 2019 to September 2020. This work was embedded into interdisciplinary design 5 MOSAiC teams, studying atmosphere, sea ice, ocean, ecosystem, biogeochemical processes. The overall aim characterize cover...
The magnitude, spectral composition, and variability of the Arctic sea ice surface albedo are key to understanding numerically simulating Earth’s shortwave energy budget. Spectral broadband albedos were spatially temporally sampled by on-ice observers along individual survey lines throughout sunlit season (April–September, 2020) during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition. seasonal evolution MOSAiC year was constructed from averaged values each line....
As part of the Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC), four autonomous seasonal ice mass balance buoys were deployed in first- and second-year ice. These measured position, barometric pressure, snow depth, thickness, growth, surface melt, bottom vertical profiles temperature from air, through ice, into upper ocean. Observed air temperatures similar at all sites; however, snow–ice interface varied by as much 10°C, primarily due to differences depth. winter...
Abstract. Wind-driven redistribution of snow on sea ice alters its topography and microstructure, yet the impact these processes radar signatures is poorly understood. Here, we examine effects over Arctic waveforms backscatter obtained from a surface-based, fully polarimetric Ka- Ku-band at incidence angles between 0∘ (nadir) 50∘. Two wind events in November 2019 during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition are evaluated. During both events, changes...
Abstract. High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of patterns relevant for future projections. Here, we present data from a new, annually dated ice core record eastern Ross Sea, named Roosevelt Island Climate Evolution (RICE) core. Comparison this with reanalysis 1979–2012 interval shows that RICE reliably captures temperature and snow precipitation variability in region. Trends over past 2700 years are shown be distinct...
Abstract Snow plays an essential role in the Arctic as interface between sea ice and atmosphere. Optical properties, thermal conductivity mass distribution are critical to understanding complex system’s energy balance distribution. By conducting measurements from October 2019 September 2020 on Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition, we have produced a dataset capturing year-long evolution physical properties snow surface scattering layer, highly...
Precise measurements of Arctic sea ice mass balance are necessary to understand the rapidly changing cover and its representation in climate models. During Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition, we made repeat point snow thickness on primarily level first- second-year (FYI, SYI) using ablation stakes gauges. This technique enabled us distinguish surface bottom (basal) melt characterize importance oceanic versus atmospheric forcing. We also evaluated...
Abstract Microstructures, including crystallographic fabric, within the margin of streaming ice can exert strong control on flow dynamics. To characterize a natural setting, we retrieved three cores, two which reached bed, from flank Jarvis Glacier, eastern Alaska Range, Alaska. The core sites lie ~1 km downstream source, with abundant water present in extracted cores and at base glacier. All exhibit dipping layers, combination debris bands bubble-free domains. Grain sizes coarsen average...
Warm air intrusions over Arctic sea ice can change the snow and surface conditions rapidly alter concentration (SIC) estimates derived from satellite-based microwave radiometry without altering true SIC. Here we focus on two warm moist during Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition that reached research vessel Polarstern in mid-April 2020. After events, SIC deviations between different satellite products, including climate data records, were observed...
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Snow and ice topography impact are impacted by fluxes of mass, energy, momentum in Arctic sea ice. We measured the on approximately a 0.5 km
Abstract The geothermal flux is an important boundary condition for ice‐sheet models because it influences whether the ice melting at bed and able to slide. Point measurements remotely sensed estimates vary widely Ross Ice Sheet. A basal temperature measurement Roosevelt Island reveals a of 84 ± 13 mW/m 2 . presence Raymond Arches, which form only divides that are frozen bed, allows inferences maximum two coastal domes along Siple Coast: Engelhardt Ridge, 85 11 Shabtaie 75 10 These indicate...
Abstract. The remoteness and extreme conditions of the Arctic make it a very difficult environment to investigate. In these polar regions covered by sea ice, wind is relatively strong due absence obstructions redistributes large part deposited snow mass, which complicates estimates for precipitation hardly distinguishable from blowing or drifting snow. Moreover, mass balance in ice system still poorly understood, notably complex structure its surface. Quantitatively assessing distribution on...
Vertical heat conduction through young ice is a major source of wintertime sea growth in the Arctic. However, field observations indicate that preferentially accumulates wind-blown snow, resulting greater snow thickness on than would be expected from precipitation alone, and hence climate models represent. As has low thermal conductivity, this additional due to redistribution will reduce actual conduction. We present new Multidisciplinary drifting Observatory for Study Arctic Climate...
Abstract. High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of patterns relevant for future projections. Here, we present data from a new, annually-dated ice core record eastern Ross Sea. Comparison Roosevelt Island Climate Evolution (RICE) records with reanalysis 1979–2012 calibration period shows that RICE reliably capture temperature and snow precipitation variability region. is compared West Antarctica (West Antarctic Ice Sheet...
Abstract. We assess the influence of snow on sea ice in experiments using Community Earth System Model version 2 for a preindustrial and 2xCO2 climate state. In climate, we find that increasing simulated accumulation results thicker cooler both hemispheres. The mass budget response differs fundamentally between two Arctic, decrease congelation growth surface melt due to snow's impact conductive heat transfer albedo, respectively. These factors dominate regions perennial but have smaller...
Warm air intrusions over Arctic sea ice can rapidly change the snow and surfaceconditions alter concentration (SIC) estimates derived from satellite-based microwave radiometry without altering true SIC.Here we focus on two warm moist that produced surface glazing duringthe Multidisciplinary drifting Observatory for Study of Climate (MOSAiC)expedition reached research vessel Polarstern in mid-April 2020. After theevents, observe increased SIC deviations between different satellite...
Abstract. We assess the influence of snow on sea ice in experiments using Community Earth System Model, version 2 for a pre-industrial and 2xCO2 climate state. In climate, we find that increasing simulated accumulation results thicker cooler both hemispheres. The mass budget response differs fundamentally between two Arctic, decrease growth melt due to snow’s impact conductive heat transfer albedo, respectively. This leads reduced amplitude annual cycle thickness. Antarctic, with snow,...
Abstract. Wind transport alters the snow topography and microstructure on sea ice through redistribution controlled by deposition erosion. The impact of these processes radar signatures is poorly understood. Here, we examine effects Arctic from Ka- Ku-band signatures. Measurements were obtained during two wind events in November 2019 MOSAiC expedition. During both events, changes waveforms backscatter coincident with surface height measured a terrestrial laser scanner are observed. At...
Abstract We developed a tilt sensor for studying ice deformation and installed our systems in two boreholes drilled close to the shear margin of Jarvis Glacier, Alaska obtain kinematic measurements streaming ice. used collected data calculate borehole by tracking orientation sensors over time. The sensors' tilts generally trended down-glacier, with an element cross-glacier flow closer margin. also evaluated results against dynamic parameters derived from Glen's exponential law explored...
The amount of snow on Arctic sea ice impacts the mass budget. Wind redistribution into open water in leads is hypothesized to cause significant wintertime loss. However, there are no direct measurements loss leads. We measured lost four Central winter 2020. find, contrary general consensus, that under typical conditions, minimal was during a cyclone delivered warm air temperatures, high winds, and snowfall, 35.0 ± 1.1 cm equivalent (SWE) lead (per unit area). This corresponded removal...
Wind-blown snow particles often contaminate Terrestrial Laser Scanning (TLS) data of covered terrain. However, common filtering techniques fail to filter wind-blown and incorrectly from the true surface due spatial distribution TLS scanning geometry. We present FlakeOut, a designed specifically snowflakes data. A key aspect FlakeOut is low false positive rate 2.8x10-4—an order magnitude lower than standard techniques—which greatly reduces number ground points that are removed. This makes...