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Dale Winebrenner

Senior Principal Physicist

Research Professor, Astrobiology Program and Earth & Space Sciences

Email

dpw@apl.washington.edu

Phone

206-543-1393

Biosketch

Dr. Winebrenners' interests are in the physics of light and radio waves, and in the exploration of icy environments on Earth and elsewhere based on that physics.

For sea ice, he has developed a physically based method to observe the springtime melting and fall freeze-up transitions on Arctic sea ice using synthetic aperture radar, and has shown that polarimetric microwave backscattering from thin sea ice depends on ice thickness and thus may be useful for remote thickness estimation. Recently he has investigated the optical fluorescence from chlorophyll in sea ice, with the aim of estimating phototrophic biomass near the ice-water interface.

Microwave emissions are used to map (decadal-scale) mean surface temperature and accumulation rate fields, for ice sheet on both Greenland and Antarctica. Most recently, Dale Winebrenner has begun to investigate meter-wavelength radar sounding of ice sheets. The first result of this work is a new means of estimating electromagnetic absorption within the ice sheet.

Department Affiliation

Polar Science Center

Education

B.S. Physics, Purdue University, 1979

M.S. Electrical Engineering, University of California, San Diego, 1980

Ph.D. Electrical Engineering, University of Washington, 1985

Publications

2000-present and while at APL-UW

Terahertz time-domain polarimetry (THz-TDP) based on the spinning E-O sampling technique: Determination of precision and calibration

Xu, K., E. Bayati, K. Oguchi, S. Watanabe, D.P. Winebrenner, and M.H. Arbab, "Terahertz time-domain polarimetry (THz-TDP) based on the spinning E-O sampling technique: Determination of precision and calibration," Opt. Express, 28, 13,482-13,496, doi:10.1364/OE.389651, 2020.

More Info

27 Apr 2020

We have developed a terahertz time-domain polarimetry (THz-TDP) system by applying frequency modulation to electro-optic sampling detection in a nonlinear crystal. We characterized the precision of this system in determining the polarization angles to be 1.3° for fixed time delay, and 0.5° for complete time-domain waveform. Furthermore, we calculated the Jones matrix of the optical components used for beam propagation to calibrate the induced systematic error. The advantages of employing this calibration approach are demonstrated on a sapphire crystal investigated at different sample test positions in transmission configuration, and using high resistivity Si, AlN and quartz in reflection geometry. The new THz-TDP technique has the advantage of not using any external polarizers, and therefore is not constrained by their optical performance limitations, such as restricted bandwidths and frequency-dependent extinction ratio. Finally, the THz-TDP technique can be easily implemented on existing time-domain spectroscopy (TDS) systems.

New estimates of ice and oxygen fluxes across the entire lid of Lake Vostok from observations of englacial radio wave attenuation

Winebrenner, D.P., P.M.S. Kintner, and J.A. MacGregor, "New estimates of ice and oxygen fluxes across the entire lid of Lake Vostok from observations of englacial radio wave attenuation," J. Geophys. Res. F: Earth Surf., 124, 795-811, doi:, 2019.

More Info

1 Mar 2019

Over deep Antarctic subglacial lakes, spatially varying ice thickness and the pressure‐dependent melting point of ice result in distinct areas of melting and freeze‐on at the ice‐water interface, that is, at the lake lid. These ice mass fluxes drive lake circulation and, because basal Antarctic ice contains air clathrate, affect the input of oxygen to the lake, with implications for subglacial life. Inferences of rates of melting and freeze‐on, that is, accretion rates, from radar layer tracking and geodesy are limited in spatial coverage and resolution. Here we develop a new method to estimate accretion rate, and the resulting oxygen input at a lake lid, using airborne radar data over Lake Vostok together with ice‐temperature and chemistry data from the Vostok ice core. Because the lake lid is a coherent reflector of known reflectivity (at our radar frequency), we can infer depth‐averaged radio wave attenuation in the ice, with a spatial resolution of ~1 km along flight lines. Spatial variation in attenuation depends mostly on variation in ice temperature near the lid, which in turn varies strongly with ice mass flux at the lid. We model ice temperature versus depth with ice mass flux as a parameter, thus linking that flux to observed depth‐averaged attenuation. The resulting map of melt and accretion rates independently reproduces features known from earlier studies but now covers the entire lid. We find that freeze‐on is dominant when integrated over the lid, with an ice imbalance of 0.05 to 0.07 km3/year, which is robust against uncertainties.

Response timescales for Martian ice masses and implications for ice flow on Mars

Koutnik, M.R., E.D. Waddington, D.P. Winebrenner, and A.V. Pathare, "Response timescales for Martian ice masses and implications for ice flow on Mars," Icarus, 225, 949-959, doi:10.1016/j.icarus.2012.09.031, 2013.

More Info

1 Aug 2013

On Earth and on Mars, ice masses experience changes in precipitation, temperature, and radiation. In a new climate state, flowing ice masses will adjust in length and in thickness, and this response toward a new steady state has a characteristic timescale. However, a flowing ice mass has a predictable shape, which is a function of ice temperature, ice rheology, and surface mass-exchange rate. In addition, the time for surface-shape adjustment is shorter than the characteristic time for significant deformation or displacement of internal layers within a flowing ice mass; as a result, surface topography is more diagnostic of flow than are internal-layer shapes. Because the shape of Gemina Lingula, North Polar Layered Deposits indicates that it flowed at some time in the past, we use its current topography to infer characteristics of those past ice conditions, or past climate conditions, in which ice-flow rates were more significant than today. A plausible range of near-basal ice temperatures and ice-flow enhancement factors can generate the characteristic geometry of an ice mass that has been shaped by flow over reasonable volume-response timescales. All plausible ice-flow scenarios require conditions that are different from present-day Mars, if the basal layers are pure ice.

More Publications

Inventions

Thermal Ice Melt Probe Including Water Jetting and Clean Sampling

Record of Invention Number: 49014

Dale Winebrenner, Justin Burnett, Tim Elam

Disclosure

13 Jul 2020

Terahertz Polarimetry for Non-destructive Testing of Thin Films

Record of Invention Number: 47831

Arbab, Bayati, Dale Winebrenner

Disclosure

20 Sep 2016

Methods and systems for assessing a burn injury

The present invention provides methods, software, and systems for assessing a burn injury.

Patent Number: 9,295,402

Hassan Arbab, Antao Chen, Dale Winebrenner, Trevor Dickey, Pierre Mourad, Matthew Klein

Patent

29 Mar 2016

More Inventions

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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