A5026146432- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Freezing and Crystallization Processes
- Meteorological Phenomena and Simulations
- Remote Sensing and LiDAR Applications
- Climate variability and models
- Icing and De-icing Technologies
- Geophysics and Gravity Measurements
- Marine animal studies overview
- Remote Sensing in Agriculture
- Species Distribution and Climate Change
- Sustainability and Ecological Systems Analysis
- Ocean Waves and Remote Sensing
- 3D Surveying and Cultural Heritage
- Ocean Acidification Effects and Responses
- Geological Studies and Exploration
- Complex Systems and Decision Making
- Scientific Research and Discoveries
- Food Industry and Aquatic Biology
- Fire effects on ecosystems
- Sustainability and Climate Change Governance
Dartmouth College
2020-2025
Dartmouth Hospital
2020-2022
University of Vermont
2010
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....
Melt ponds on sea ice play an important role in the Arctic climate system. Their presence alters partitioning of solar radiation: decreasing reflection, increasing absorption and transmission to ocean, enhancing melt. The spatiotemporal properties melt thus modify albedo feedbacks mass balance ice. Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition presented a valuable opportunity investigate seasonal evolution through rich array atmosphere-ice-ocean measurements...
Repeated transects have become the backbone of spatially distributed ice and snow thickness measurements crucial for understanding mass balance. Here we detail at Multidisciplinary drifting Observatory Study Arctic Climate (MOSAiC) 2019–2020, which represent first such collected across an entire season. Compared with similar historical transects, MOSAiC was thin (mean depths approximately 0.1–0.3 m), while sea relatively thick first-year (FYI) second-year (SYI). SYI two distinct types: level...
Abstract. Data from the Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition allowed us to investigate temporal dynamics snowfall, snow accumulation and erosion in great detail almost whole season (November 2019 May 2020). We computed cumulative water equivalent (SWE) over sea ice based on depth density retrievals a SnowMicroPen approximately weekly measured depths along fixed transect paths. used derived SWE cover compare with precipitation sensors...
During the Arctic melt season, relatively fresh meltwater layers can accumulate under sea ice as a result of snow and melt, far from terrestrial freshwater inputs. Such under-ice layers, sometimes referred to ponds, have been suggested play role in summer mass balance both by isolating saltier water below, driving formation ‘false bottoms’ below ice. form at interface fresher layer colder, seawater below. Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition Central...
Abstract. Changes in Arctic sea ice thickness are the result of complex interactions dynamic and variable cover with atmosphere ocean. Most exiting Ocean does so through Fram Strait, which is why long-term measurements at end Transpolar Drift provide insight into integrated signals thermodynamic influences along pathways ice. We present an updated summer (July–August) time series extensive surveys carried out between 2001 2020. Overall, we see a more than 20 % thinning modal since 2001. A...
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...
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. The melt of snow and sea ice during the Arctic summer is a significant source relatively fresh meltwater. fate this freshwater, whether in surface ponds or thin layers underneath leads, impacts atmosphere–ice–ocean interactions their subsequent coupled evolution. Here, we combine analyses datasets from Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition (June–July 2020) process study on formation freshwater floes Central Arctic. Our budget suggest that high...
Abstract. Snow is a critical component of the Arctic sea ice system. With its low thermal conductivity and high albedo, snow moderates energy transfer between atmosphere ocean during both winter summer, thereby playing significant role in determining magnitude, timing, variability growth melt. The depth on highly variable space time, accurate measurements are central to improving our basic understanding, model representation, remote sensing observations Our ability collect those has hitherto...
Abstract The formation of platelet ice is well known to occur under Antarctic sea ice, where subice layers form from supercooled shelf water. In the Arctic, however, has not been extensively observed, and its morphology currently remain enigmatic. Here, we present first comprehensive, long‐term in situ observations a decimeter thick layer free‐drifting pack Central Arctic winter. Observations carried out with remotely operated underwater vehicle (ROV) during midwinter leg MOSAiC drift...
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...
Abstract. Data from the Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition allowed us to investigate temporal dynamics snowfall, snow accumulation, and erosion in great detail almost whole accumulation season (November 2019 May 2020). We computed cumulative water equivalent (SWE) over sea ice based on depth (HS) density retrievals a SnowMicroPen (SMP) approximately weekly-measured depths along fixed transect paths. Hence, SWE considers surface...
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 Snow depth on sea ice is an Essential Climate Variable and a major source of uncertainty in satellite altimetry‐derived thickness. During winter the MOSAiC Expedition, “KuKa” dual‐frequency, fully polarized Ku‐ Ka‐band radar was deployed “stare” nadir‐looking mode to investigate possibility combining these two frequencies retrieve snow depth. Three approaches were investigated: dual‐polarization waveform shape, compared independent measurements. Novel yielded r 2 values up 0.77....
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...
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...
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...
Abstract. The melt of snow and sea ice during the Arctic summer is a significant source relatively fresh meltwater in central Arctic. fate this freshwater – whether surface ponds, or thin layers underneath leads impacts atmosphere-ice-ocean interactions their subsequent coupled evolution. Here, we combine analyses datasets from Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition (June–July, 2020) to understand key drivers budget Central water over time. Freshwater...
Abstract. Changes in Arctic sea ice thickness are the result of complex interactions dynamic and variable cover with atmosphere ocean. Most exits Ocean through Fram Strait, which is why long-term measurements at end Transpolar Drift provide insight into integrated signals thermodynamic influences along pathways ice. We present an updated time series extensive surveys carried out between 2001 2020. Overall, we see a more than 20 % thinning modal since 2001. A comparison first preliminary...