Campus Map

Dale Winebrenner

Senior Principal Physicist

Research Professor, Astrobiology Program and Earth & Space Sciences






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


B.S. Physics, Purdue University, 1979

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

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


2000-present and while at APL-UW

Microbial transport by a descending ice melting probe: Implications for subglacial and ocean world exploration

Schuler, C.G., D.P. Winebrenner, W.T. Elam, J. Burnett, B.W. Boles, and J.A. Mikucki, "Microbial transport by a descending ice melting probe: Implications for subglacial and ocean world exploration," Astrobiology, EOR, doi:10.1089/ast.2021.0106, 2023.

More Info

6 Jun 2023

Ocean Worlds beneath thick ice covers in our solar system, as well as subglacial lakes on Earth, may harbor biological systems. In both cases, thick ice covers (>100 s of meters) present significant barriers to access. Melt probes are emerging as tools for reaching and sampling these realms due to their small logistical footprint, ability to transport payloads, and ease of cleaning in the field. On Earth, glaciers are immured with various abundances of microorganisms and debris. The potential for bioloads to accumulate around and be dragged by a probe during descent has not previously been investigated. Due to the pristine nature of these environments, minimizing and understanding the risk of forward contamination and considering the potential of melt probes to act as instrument-induced special regions are essential. In this study, we examined the effect that two engineering descent strategies for melt probes have on the dragging of bioloads. We also tested the ability of a field cleaning protocol to rid a common contaminant, Bacillus. These tests were conducted in a synthetic ice block immured with bioloads using the Ice Diver melt probe. Our data suggest minimal dragging of bioloads by melt probes, but conclude that modifications for further minimization and use in special regions should be made.

Experimental validation of cryobot thermal models for the exploration of ocean worlds

Pereira, P.D., and 19 others including D.P. Winebrenner and W.T. Elam, "Experimental validation of cryobot thermal models for the exploration of ocean worlds," Planet. Sci. J., 4, doi:10.3847/PSJ/acc2b7, 2023.

More Info

5 May 2023

Accessing the potentially habitable subsurface waters of Ocean Worlds requires a robotic ice probe (or "cryobot") to traverse tens of kilometers of ice with temperatures ranging from ~100 to 273 K. Designing and planning such a mission requires understanding ice probe behavior as a function of the local environment and design parameters. We present experimental results of two laboratory melt probes in cryogenic (79 K) and warm (253 K) ice. The melt probe tested in warm ice had multiple adjustable heaters, enabling optimization of the system's efficiency. The melt probes tested in cryogenic ice operated in vacuum and had internal tether spools, allowing for experimental confirmation of hole closure and the creation of a pressurized pocket with liquid water around the probe. These melt probes were tested at power levels ranging from 120 to 1135 W, achieving descent speeds between 5.3 and 59 cm hr-1. By analyzing the relationship between power and speed using analytical and high-fidelity numerical models, we demonstrate progress in understanding melt probe performance. We distinguish between the previously confounding terms of probe operational inefficiency and analytical model inaccuracy, allowing us to understand the range of applicability of the analytical models and demonstrate the importance of controlling heat distribution in cryobot design. The validated models show that while numerical models may be required to describe the behavior of short probes descending in limited-size laboratory test beds, the performance of efficient cryobots designed for operation on Ocean Worlds can be predicted by analytical models within 5% error.

Avoiding slush for hot-point drilling of glacier boreholes

Hills, B.H., D.P. Winebrenner, W.T. Elam, and P.M.S. Kintner, "Avoiding slush for hot-point drilling of glacier boreholes," Ann. Glaciol., 62, 166-170, doi:10.1017/aog.2020.70, 2021.

More Info

1 Apr 2021

Water-filled boreholes in cold ice refreeze in hours to days, and prior attempts to keep them open with antifreeze resulted in a plug of slush effectively freezing the hole even faster. Thus, antifreeze as a method to stabilize hot-water boreholes has largely been abandoned. In the hot-point drilling case, no external water is added to the hole during drilling, so earlier antifreeze injection is possible while the drill continues melting downward. Here, we use a cylindrical Stefan model to explore slush formation within the parameter space representative of hot-point drilling. We find that earlier injection timing creates an opportunity to avoid slush entirely by injecting sufficient antifreeze to dissolve the hole past the drilled radius. As in the case of hot-water drilling, the alternative is to force mixing in the hole after antifreeze injection to ensure that ice refreezes onto the borehole wall instead of within the solution as slush.

More Publications

In The News

UW part of $25M NSF-funded effort to retrieve Earth’s oldest ice core

UW News

The new Center for Oldest Ice Exploration, or COLDEX, will be created under a five-year, $25 million National Science Foundation grant. Roughly $5 million of that grant will go to the UW. One aspect of COLDEX will involve new development of a probe, the Ice Diver, that melts through layers of ice and provides information about the age of the ice and other data without having to lift a core back up to the surface.

14 Sep 2021

Researchers test ice probe on Mount Baker

Skagit Valley Herald, Kimberly Cauvel

APL-UW researchers received help from a local snowmobile club to reach Mount Baker's Easton Glacier at an elevation of about 8000 feet to conduct tests of the 'ice diver' probe — an electrically-heated instrument that pierces glacial ice to measure the physical and biological environments below.

15 Jun 2019

The ice of a distant moon

Science News, Meghan Rosen

Scientists around the world are trying to figure out how to pierce the thick, icy shell of Europa to search for life below. Dale Winebrenner is quoted.

2 May 2014

More News Items

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