A5090076560- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Climate variability and models
- Atmospheric chemistry and aerosols
- Arctic and Antarctic ice dynamics
- Geology and Paleoclimatology Research
- Climate change and permafrost
- Meteorological Phenomena and Simulations
- Atmospheric Ozone and Climate
- Methane Hydrates and Related Phenomena
- Groundwater and Isotope Geochemistry
- Air Quality and Health Impacts
- Atmospheric aerosols and clouds
- Radioactive contamination and transfer
- Educational Assessment and Pedagogy
- Calibration and Measurement Techniques
- Statistics Education and Methodologies
- Polar Research and Ecology
- Adaptive optics and wavefront sensing
- Innovative Teaching and Learning Methods
- Air Quality Monitoring and Forecasting
- Freezing and Crystallization Processes
- Aerospace Engineering and Energy Systems
- Fluid Dynamics and Turbulent Flows
- Precipitation Measurement and Analysis
Earth and Space Research
2024-2025
Seattle University
2024
Bjerknes Centre for Climate Research
2021-2024
University of Bergen
2021-2024
Earth Science Institute of the Slovak Academy of Sciences
2023
University Prep
2012
Centre National de la Recherche Scientifique
2009-2010
Université Joseph Fourier
2009-2010
Laboratoire de Glaciologie et Géophysique de l’Environnement
2009-2010
University of Washington
2004-2008
Six levels of meteorological sensors have been deployed along a 45 m tower at the French‐Italian Concordia station, Dome C, Antarctic. We present measurements vertical profiles, diurnal cycle, and interdiurnal variability temperature, humidity, wind speed direction for 3 weeks during southern summer 2008. These are compared to 6‐hourly European Center Medium‐Range Forecasts (ECMWF) analyses daily radiosoundings. The ECMWF show 3–4°C warm bias relative observations. They reproduce cycle...
The Concordiasi project is making innovative observations of the atmosphere above Antarctica. most important goals are as follows: To enhance accuracy weather prediction and climate records in Antarctica through assimilation situ satellite data, with an emphasis on data provided by hyperspectral infrared sounders. focus clouds, precipitation, mass budget ice sheets. improvements dynamical model analyses forecasts will be used chemical-transport models that describe links between polar vortex...
Abstract Surface processes alter the water stable isotope signal of surface snow after deposition. However, it remains an open question to which extent post‐depositional should be considered when inferring past climate information from ice core records. Here, we present simulations for Greenland Ice Sheet, combining outputs two models with isotope‐enabled snowpack model. We show that vapor exchange and associated fractionation imprint a into firn, resulting in increase annual mean value δ 18...
A Rayleigh fractionation model is developed to investigate postdepositional modification of stable isotopes water in the near‐surface snow East Antarctica. The processes forced ventilation, pore‐space diffusion, and intra‐ice‐grain diffusion are parameterized through characteristic time constants. Routine meteorological observations, their derived products, general glaciological conditions from South Pole used simulate δ 18 O as it evolves time. sensitivity wind speed, surface temperature,...
Dome C, Antarctica, (75° south, 123° east, 3250 m) is one of the coldest and driest locations on Earth, with exceptionally low winds throughout atmosphere. It therefore has potential to be an ideal site for astronomical observations. also excellent validation satellite instruments. A Fourier transform infrared interferometer was deployed at C during two austral summer seasons (2003 January 2003 December/2004 January) purpose acquiring data. However, these data are useful understanding...
The Program for Research on Oxidants: Photochemistry, Emissions, and Transport (PROPHET) summer 1998 measurements intensive was conducted from a tower above forested site in northern Michigan. This paper provides brief overview of the meteorological conditions establishes that study period moderately drier warmer than climatological mean. also identifies chemically characterizes major air mass types influencing site. Meteorological analyses back trajectories establish origin oscillated...
Abstract Annual cycles of downwelling broadband infrared radiative flux and spectral were determined using data collected at the South Pole during 2001. Clear-sky conditions are identified by comparing radiance ratios observed simulated spectra. fluxes in range 110–125 W m−2 summer (December–January) 60–80 winter (April–September). The variability is due to day-to-day variations temperature, strength surface-based temperature inversion, atmospheric humidity, presence “diamond dust”...
Abstract Estimates of cloud cover over the South Pole are presented from five different data sources: routine visual observations (1957–2004; Cvis), surface-based spectral infrared (IR) (2001; CPAERI), broadband IR (1994–2003; Cpyr), Extended Advanced Very High Resolution Radiometer (AVHRR) Polar Pathfinder (APP-x) dataset (1994–99; CAPP-x), and International Satellite Cloud Climatology Project (ISCCP) CISCCP). The seasonal cycle is found to range 45%–50% during short summer a relatively...
Abstract On polar ice sheets, water vapor interacts with surface snow, and through the exchange of molecules, imprints an isotopic climate signal into sheet. This is not well understood due to sparse observations in atmosphere. There are currently no published vertical profiles isotopes above sheets that span planetary boundary layer portions free troposphere. Here, we present a novel data set water‐vapor (O, D, ) meteorological variables taken by fixed‐wing uncrewed aircraft on northeast...
The annual sea ice minimum extent in the Arctic Ocean has decreased almost two-fold since advent of satellite observations 1970s, leaving more open water before fall freeze-up.  Here, we leverage a combined dataset from 2022 NASA Salinity and Stratification at Sea Ice Edge (SASSIE) field program to elucidate central hypothesis that drove SASSIE: Does surface salinity stratification due melt, precipitation, riverine inputs lead changes rates or autumnal advance? SASSIE study region...
Abstract A finite-volume model is used to simulate 9 years (1995–2003) of snow temperatures at the South Pole. The upper boundary condition skin-surface temperature derived from routine upwelling longwave radiation measurements, while lower set seasonal gradient 6.5 m depth, taken prior measurements We focus on statistics temperature, heat fluxes, heating rates and vapour pressures in top metre snow, but present results full depth (6.5 m). monthly mean net flux into agrees with previous...
Routine radiation and meteorological data at South Pole Station are used to investigate historical discrepancies of up 50 W m −2 in the monthly mean surface energy budget behavior turbulent heat fluxes under stable atmospheric temperature conditions. The seasonal cycles net approximately equal, with a difference 40 between summer winter, while cycle subsurface is only few . For an 8‐month period (the winter 2001), we calculate two estimates fluxes, one from Monin‐Obukhov (MO) similarity...
Abstract. We document the isotopic evolution of near-surface snow at East Greenland Ice Core Project (EastGRIP) ice core site in northeast using a time-resolved array 1 m deep isotope (δ18O, δD) profiles. The profiles were taken from May–August during 2017–2019 summer seasons. An age–depth model was developed and applied to each profile, mitigating impacts stratigraphic noise on signals. Significant changes deuterium excess (d) are observed surface as ages. Decreases d up 5 ‰ occur seasons...
The response of radiosondes to an instantaneous change environment was studied by taking the instruments from a warm building into cold at South Pole Station. After being initialized inside, were carried outside and placed on snow surface, where they left until reported stable values temperature, pressure, relative humidity. Three models tested: Vaisala RS80, Atmospheric Instrumentation Research (AIR) 4A, AIR 5A. temperature equilibrated conditions within 30 s. However, it frequently took...
Abstract. Summit, Greenland is a remote Arctic research station allowing for field measurements at the highest point of Ice Sheet. Due to current reliance on diesel generators electricity unavoidable local emissions are potential contamination threat measurement combustion-related species in air and snow. The effect fossil-fuel combustion particulate elemental carbon (EC) assessed by combination ambient (~1 km from main camp), series snow pits, Gaussian plume modeling. Ambient indicate that...
Continuous measurements of peroxyacetyl nitrate (PAN), peroxypropionyl (PPN), and ozone (O 3 ) were made from June 1997 through August 1999 at a ground site in the upper Midwest as part Program for Research on Oxidants: Photochemistry, Emissions, Transport (PROPHET). Relatively clean air originating Canada is transported to northwest, while more polluted metropolitan regions mainly southwest southeast. Monthly averages PAN are minimum summer /early winter (July‐January) with mixing ratios...
Abstract. We document the isotopic evolution of near-surface snow at EastGRIP ice core site in Northeast Greenland National Park using a time-resolved array 1-m deep isotope (δ18O, δD) profiles. The profiles were taken from May–August during 2017–2019 summer seasons. An age-depth model was developed and applied to each profile mitigating impacts stratigraphic noise on signals. Significant changes deuterium excess (d) are observed surface as ages. Decreases d up 5 ‰ occurs seasons after...
Measurements of pan evaporation were made during the summers 1957 and 1958 on an ice station drifting between 80° 86°N. Using weather reports, measurements either screened for absence precipitation (to obtain evaporation, E ) or not P‐E ). Applying data to entire month only days without results in upper lower limits . Monthly average values are positive June July, 3–5 5–8 mm/month, within range prior estimates, but negative August September, indicating net deposition frost dew, at variance...
Abstract Clouds have a large effect on the radiation budget and represent major source of uncertainty in climate models. Supercooled liquid clouds can exist at temperatures as low 235 K, radiative these depends complex refractive index (CRI) water. Laboratory measurements demonstrated that liquid‐water CRI is temperature‐dependent, but corroboration with field difficult. Here we present downwelling infrared radiance in‐situ supercooled water cloud 240 made South Pole Station 2001. These...
Onset of surface melt over sea ice is a factor in the duration season. often triggered by advection warm, moist air from lower latitudes. This especially characteristic early dates onset, but such events have also been hypothesized to precondition for an earlier onset even when they don’t act as trigger. The importance atmospheric season well-recognized community. Less attention has given potential limitations these and what alternate mechanisms may be important initiation, which...
Climate change is a major concern to undergraduate students. Understanding climate relies on an understanding of polar regions. However, courses regions are rare at institutions. Polar ENgagement through GUided INquiry (PENGUIN) modules were designed give students experience with research in variety standard courses, including physics, computer science, physical chemistry, and economics, using course-specific computational tools analyze data. Here, we present new PENGUIN module taught...