A5057186341- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Geological Studies and Exploration
- Oceanographic and Atmospheric Processes
- Climate variability and models
- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Atmospheric and Environmental Gas Dynamics
- Space Exploration and Technology
- Arctic and Russian Policy Studies
- Icing and De-icing Technologies
- Marine and Coastal Research
- Meteorological Phenomena and Simulations
- Marine animal studies overview
- Freezing and Crystallization Processes
- Groundwater and Isotope Geochemistry
- Ocean Acidification Effects and Responses
- Indigenous Studies and Ecology
- Distributed and Parallel Computing Systems
- Food Industry and Aquatic Biology
- Maritime Navigation and Safety
- Pleural and Pulmonary Diseases
- Atmospheric Ozone and Climate
Oregon State University
2015-2024
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2024
John Brown University
2023
Brown University
2023
Moss Landing Marine Laboratories
2023
Naval Postgraduate School
2023
Utah AIDS Foundation
2021
University of Alaska Fairbanks
2003-2020
University of Maryland, College Park
2020
Earth System Science Interdisciplinary Center
2020
Abstract The loss of Arctic sea ice has emerged as a leading signal global warming. This, together with acknowledged impacts on other components the Earth system, led to term “the new Arctic.” Global coupled climate models predict that will continue through twenty-first century, implications for governance, economics, security, and weather. A wide range in model projections reflects complex, highly interactions between polar atmosphere, ocean, cryosphere, including teleconnections lower...
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...
Sea ice growth and decay are critical processes in the Arctic climate system, but comprehensive observations very sparse. We analyzed data from 23 sea mass balance buoys (IMBs) deployed during Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition 2019–2020 to investigate seasonality timing thermodynamic Transpolar Drift. The reveal four stages season: (I) onset basal freezing, mid-October November; (II) rapid growth, December–March; (III) slow April–May; (IV)...
Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic dynamic processes alter sea thickness. The Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition provided unique opportunity to study seasonal changes same ice. We analyzed 11 large-scale (∼50 km) airborne electromagnetic surface roughness surveys from October 2019 September 2020. Data mass balance position buoys additional information. found that thermodynamic growth decay...
The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) was a yearlong expedition supported by icebreaker R/V Polarstern, following Transpolar Drift from October 2019 to 2020. campaign documented an annual cycle physical, biological, and chemical processes impacting atmosphere-ice-ocean system. Of central importance were measurements thermodynamic dynamic evolution sea ice. A multi-agency international team led University Colorado/CIRES NOAA-PSL observed...
Abstract Sea ice drift estimates from feature tracking of satellite passive microwave data are used to investigate seasonal trends and variability in the circulation around Beaufort Gyre, over multidecadal period 1980–2013. Our results suggest an amplified response Gyre wind forcing, especially during late 2000s. We find increasing anticyclonic across all seasons, with strongest trend autumn, associated increased export out southern (into Chukchi Sea). A flux gate analysis highlights...
Central Arctic properties and processes are important to the regional global coupled climate system. The Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) Distributed Network (DN) autonomous ice-tethered systems aimed bridge gaps in our understanding temporal spatial scales, particular with respect resolution Earth system models. By characterizing variability around local measurements made at a Observatory, DN covers both interactions involving ocean-ice-atmosphere...
Abstract In late March 2007 an array of GPS ice drifters was deployed in the Beaufort Sea as part Ice Experiment: Dynamic Nature Arctic (SEDNA). were designed to resolve four, nested spatial scales sea-ice deformation, from 10 140 km, with arrays maintaining appropriate shape for strain-rate calculation until mid-June. this paper, we test whether deformation displays fractal properties vicinity SEDNA. We identify that time series have different spectral depending on scale. At around 100 is a...
Ice Station Polarstern (ISPOL), deployed in the western Weddell Sea from November 2004 to January 2005, included a study of subsynoptic scale variability sea ice velocity and deformation using an array 24 buoys. Upon deployment, ISPOL buoy measured 70 km both zonal meridional extent consisted subarrays that resolved on scales 10 km. Across array, divergence varied did not show distinct coherent length scale. Spectral analysis shear revealed vary smoothly across array. This indicates internal...
A new record minimum in summer sea ice extent was set 2007 and an unusual polynya formed the Beaufort Sea cover during of 2006. Using a combination visual observations from cruises, drift, satellite passive microwave concentration, we show that dynamics preceding years included events preconditioned pack for patterns opening observed both summers. Intrusions first year Chukchi to Northern Beaufort, increased pole‐ward transport western Arctic has led reduced replenishment multiyear ice,...
Abstract Beaufort Sea ice motion is episodic in winter, on average following the anticyclonic of Gyre. Weather systems cause pack to fracture characteristic patterns that depend location and trajectory weather system relation coast. The majority leads associated with are coastal form perpendicular from promontories along coast landfast edge. Between 40% 90% (depending coast) winter sea leads, including flaw interior lead patterns. In much Gyre drift results ice‐coast interaction, high...
Abstract Dissolved organic matter (DOM) absorption and fluorescence properties were investigated for seawater samples collected from the polar mixed layer (0–30 m) of Canada Basin in 2010–2012. Sea ice concentration as well fractions meteoric sea meltwater (f MW f SIM ) calculated oxygen isotope ratio (δ 18 O) applied to assess importance discrete freshwater inputs distribution DOM. Parallel factor analysis identified four humic‐like (C1‐2 C4‐C5) one protein‐like (C3) fluorescent components...
Abstract Sea ice modulates the energy exchange between atmosphere and ocean through its kinematics. Marginal zone (MIZ) dynamics are complex not well resolved in routine observations. Here, we investigate sea Greenland MIZ using situ remote sensing Lagrangian drift datasets. These datasets provide a unique view into spanning spatial scales. We find evidence of tidal currents strongly affecting sub‐daily motion. Velocity anomalies show abrupt transitions aligned with gradients seafloor...
Sea ice is made up of individual pieces called floes, and these floes can vary in size from scales just metres to tens kilometres. There has been much recent interest simulating variable floe continuum models sea ice, since impact the evolution cover via several mechanisms including lateral melt volume, rheology, momentum exchange. These simulations usually only account for breakup driven by waves. Observations Arctic show that there also exists in-plane failure resulting processes wind...
Abstract. Winds blew a record large portion of the Arctic's multiyear sea ice (MYI) into southern Beaufort Sea (SBS) in winter 2021. From early March, network buoys from Ice Dynamic Experiment (SIDEx) tracked MYI as it drifted across SBS toward Chukchi Sea. Transport was episodic consolidated pack interacted with coastal boundaries and repeatedly fractured. We investigated variability 2021 transport by relating situ drift to remotely sensed coastal-lead opening events, which have been...
Abstract We combine Eulerian ice draft observations from moored ice‐profiling sonars with buoy‐ and satellite‐derived drift data to obtain Lagrangian of changes in the thickness distribution sea circulating Beaufort Sea. examine repeat measurements by identifying events where buoys or pseudobuoys made overpasses within 30 km sonar‐equipped Gyre Exploration Project moorings. Comparison distributions each overpass indicates that summertime melt rates are related track, more occurring southern...
Abstract The evolution of the near-inertial internal wavefield from ice-free summertime conditions to ice-covered wintertime is examined using data a yearlong deployment six moorings on Beaufort continental slope August 2008 2009. When ice absent, July October, energy efficiently transferred atmosphere ocean, generating waves. present, November June, storms also cause oscillations in and mixed layer, but kinetic weaker are quickly damped. Damping dependent pack strength morphology. Decay...
Abstract Remotely sensed derivation of sea-ice thickness requires sea·ice density. Sea-ice density was estimated with three techniques during the second Sea Ice Physics and Ecosystem eXperimett (SIPEX-II, September-November 2012, East Antarctica). The sea ice first-year highly deformed, mean thicknsss 1.2 m layers, consistent rafting, 6-7/10 columnar 3/10 granular ice. found to be lower than values (900-920 kg −3 used previously derive thickness,, 870 − 3 . At two different stations 800 –3 ,...
SPECIALTY GRAND CHALLENGE article Front. Earth Sci., 14 August 2017Sec. Cryospheric Sciences Volume 5 - 2017 | https://doi.org/10.3389/feart.2017.00064
Abstract A network of autonomous, ice-tethered buoys was deployed around the Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) experiment in late September 2019 a year-long drift Transpolar Drift Stream. The were as part MOSAiC distributed (DN) which included 12 multi-instrumented ice stations and an additional 116 GPS primarily within 40 km radius Central Observatory. Buoy coverage DN maintained with deployments throughout allowing collection data over full sea growth...
Abstract Sea ice deformation is localized in narrow zones of high strain rate that extend hundreds kilometers, for example, across the Arctic Basin. This paper demonstrates these failure may be modeled with a viscous–plastic sea model, using an isotropic rheology. If assumed to heterogeneous at grid scale, and allowed weaken time, intersecting propagate region. The direction propagation depends upon stress applied (wind boundary conditions) rheological model describing plastic ice. spacing...
During spring 2003, the deformation of a single lead in Beaufort Sea was investigated using four Global Positioning System recording stations. The situated first‐year ice, transition zone between multiyear, and seasonal ice packs. We discuss opening rate shear this context weather system forcing sea ice. It is found that an mode, displays semidiurnal fluctuations divergence. also observed predominately ridged closing. volume same order magnitude as growth within study region during time...
Ocean/ice interface heat fluxes ( F 0 ) are calculated from upper ocean measurements obtained autonomous systems repeatedly deployed in the Arctic Ocean Transpolar Drift between 2002 and 2010. Average values over nine summer heating season realizations varied 4.6 10.5 W m −2 with an average value of 7.6 . Between 2010, summer‐averaged passed through a clear minimum, most inter‐annual variability dominated by differences content, rather than surface forcing. We test if is supported primarily...