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Jim Thomson

Senior Principal Oceanographer

Professor, Civil and Environmental Engineering

Email

jthomson@apl.washington.edu

Phone

206-616-0858

Research Interests

Environmental Fluid Mechanics, Ocean Surface Waves, Marine Renewable Energy (tidal and wave), Coastal and Nearshore Processes, Ocean Instrumentation

Biosketch

Dr. Thomson studies waves, currents, and turbulence by combining field observations and remote sensing techniques

Education

B.A. Physics, Middlebury College, 2000

Ph.D. Physical Oceanography, MIT/WHOI, 2006

Projects

Hurricane Coastal Impacts

APL-UW scientists are collaborating with 10 research teams to tackle the National Oceanographic Partnership Program (NOPP) project goals: to enable better understanding and predictive ability of hurricane impacts, to serve and protect coastal communities. The APL-UW team will contribute air-deployed buoys to provide real time observations of hurricane waves and wave forcing that can be ingested by modeling groups, improving forecasts and validating hindcasts.

14 Dec 2021

Wave Glider Observations in the Southern Ocean

A Wave Glider autonomous surface vehicle will conduct a summer-season experiment to investigate ocean–shelf exchange on the West Antarctic Peninsula and frontal air–sea interaction over both the continental shelf and open ocean.

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4 Sep 2019

Southern Ocean climate change is at the heart of the ocean's response to anthropogenic forcing. Variations in South Polar atmospheric circulation patterns, fluctuations in the strength and position of the Antarctic Circumpolar Current, and the intertwining intermediate deep water cells of the oceanic meridional overturning circulation have important impacts on the rate of ocean carbon sequestration, biological productivity, and the transport of heat to the melting continental ice shelves.

Wave Measurements at Ocean Weather Station PAPA

As part of a larger project to understand the impact of surface waves on the ocean mixed layer, APL-UW is measuring waves at Ocean Weather Station Papa, a long-term observational site at N 50°, W 145°.

29 Aug 2019

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Videos

microSWIFTs: Tiny Oceanographic Floats Measure Extreme Coastal Conditions

These small, inexpensive ocean drifters are the latest generation of the Surface Wave Instrument Float with Tracking (SWIFT) platform developed at APL-UW. They are being used in several collaborative research experiments to increase the density of nearshore wave observations.

19 Apr 2022

Using a Wave Energy Converter for UUV Recharge

This project demonstrates the interface required to operate, dock, and wirelessly charge an uncrewed underwater vehicle with a wave energy converter.

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11 Apr 2022

Uncrewed underwater vehicles (UUVs) predominantly use onboard batteries for energy, limiting mission duration based on the amount of stored energy that can be carried by the vehicle. Vehicle recharge requires recovery using costly, human-supported vessel operations. The ocean is full of untapped energy in the form of waves that, when converted to electrical energy by a wave energy converter (WEC), can be used locally to recharge UUVs without human intervention. In this project we designed and developed a coupled WEC-UUV system, with emphasis on the systems developed to interface the UUV to the WEC.

Mapping Underwater Turbulence with Sound

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9 Apr 2018

To dock at a terminal, large Washington State ferries use their powerful engines to brake, generating a lot of turbulence. Doppler sonar instruments are capturing an accurate picture of the turbulence field during docking procedures and how it affects terminal structures and the seabed. This research is a collaborative effort between APL-UW and the UW College of Engineering, Department of Civil and Environmental Engineering.

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Publications

2000-present and while at APL-UW

Relative current effect on short wave growth

Guimarães, P.V., F. Ardhuin, Y. Perignon, A. Benetazzo, M.-N. Bouin, V. Garnier, J.-L. Redelsperger, M. Accensi, and J. Thomson, "Relative current effect on short wave growth," Ocean Dyn., EOR, doi:10.1007/s10236-022-01520-0, 2022.

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6 Aug 2022

Short waves growth is characterized by nonlinear and dynamic processes that couple ocean and atmosphere. Ocean surface currents can have a strong impact on short wave steepness and breaking, modifying the surface roughness, and consequently their growth. However, this interplay is poorly understood and observations are scarce. This work uses in situ measurements of near-surface winds, surface current, and waves under strong tidal current conditions to investigate the relative wind speed effect on the local short waves growth. Those observations were extensive compared with numerical modeling using WAVEWACHIII, where the simulations repeatedly fail to reproduce the observed wind sea energy under strong current conditions. Our field observations and coupled ocean-atmosphere numerical simulations suggest that surface currents can strongly modulate surface winds. That is a local process, better observed closer to the boundary layer than at 10 m height. Yet, it can cause a significant impact on the local wind shear estimation and consequently on the local waves’ growth source term. The results presented here show that the relative wind effect is not well solved inside spectral waves models, causing a significant bias around the peak of wind sea energy.

Air-ice-ocean interactions and the delay of autumn freeze-up in the Western Arctic Ocean

Thomson, J., M. Smith, K. Drushka, and C. Lee, "Air-ice-ocean interactions and the delay of autumn freeze-up in the Western Arctic Ocean," Oceanography, 35, doi:10.5670/oceanog.2022.124, 2022.

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15 Jun 2022

Arctic sea ice is becoming a more seasonal phenomenon as a direct result of global warming. Across the Arctic, the refreezing of the ocean surface each autumn now occurs a full month later than it did just 40 years ago. In the western Arctic (Canada Basin), the delay is related to an increase in the seasonal heat stored in surface waters; cooling to the freezing point requires more heat loss to the atmosphere in autumn. In the marginal ice zone, the cooling and freezing process is mediated by ocean mixing and by the presence of remnant sea ice, which may precondition the ocean surface for refreezing. The delay in refreezing has many impacts, including increased open ocean exposure to autumn storms, additional wave energy incident to Arctic coasts, shifts in animal migration patterns, and extension of the time window for transit by commercial ships along the Northern Sea Route. This article reviews the observed trends in the western Arctic and the processes responsible for these trends, and provides brief in situ observations from the Beaufort Sea that illustrate some of these processes.

Variations in wave slope and momentum flux from wave–current interactions in the tropical trade winds

Iyer, S., J. Thomson, E. Thompson, and K. Drushka, "Variations in wave slope and momentum flux from wave–current interactions in the tropical trade winds," J. Geophys. Res., 127, doi:10.1029/2021JC018003, 2022.

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1 Mar 2022

Observations from six Lagrangian Surface Wave Instrument Float with Tracking drifters in January–February 2020 in the northwestern tropical Atlantic during the Atlantic Tradewind Ocean–atmosphere Mesoscale Interaction Campaign are used to evaluate the influence of wave–current interactions on wave slope and momentum flux. At observed wind speeds of 4––12 ms-1, wave mean square slopes are positively correlated with wind speed. Wave-relative surface currents varied significantly, from opposing the wave direction at 0.24 ms-1 to following the waves at 0.47 ms-1. Wave slopes are 5%–10% higher when surface currents oppose the waves compared to when currents strongly follow the waves, consistent with a conservation of wave energy flux across gradients in currents. Assuming an equilibrium frequency range in the wave spectrum, wave slope is proportional to wind friction velocity and momentum flux. The observed variation in wave slope equates to a 10%–20% variation in momentum flux over the range of observed wind speeds (4–12 ms-1), with larger variations at higher winds. At wind speeds over 8 ms-1, momentum flux varies by at least 6% more than the variation expected from current-relative winds alone, and suggests that wave-current interactions can generate significant spatial and temporal variability in momentum fluxes in this region of prevailing trade winds. Results and data from this study motivate the continued development of fully coupled atmosphere-ocean-wave models.

More Publications

In The News

See delicate rib vortices encircle breaking ocean waves

Scientific American, Joanna Thompson

These little-studied mini twisters form beautiful loops under the water’s surface. Until the past decade or so few people in the scientific community paid much attention to rib vortices, partly because they are difficult to photograph. The ephemeral twists require a high-resolution camera and precise timing to capture.

1 Aug 2022

U.S. icebreaker gap with Russia a growing concern as Arctic 'cold war' heats up

Washington Times, Mike Glenn

Warming trends have spurred a chase for trade routes, natural resources at top of the world. Vessels like the Healy and the Polar Star are the most effective tools for maintaining access to the icy regions for scientific, economic and security purposes, advocates say.

23 Sep 2021

Spiraling Crisis: The Alarming Convergence of Climate Change and Pandemics

ThinkTech Hawaii

In this video documentary available on YouTube, Jim Thomson is interviewed to share the impacts of the pandemic on his research into coastal ocean dynamics in the Arctic.

16 Aug 2021

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Inventions

SWIFT v4

Record of Invention Number: 48200

Jim Thomson, Alex de Klerk, Joe Talbert

Disclosure

6 Nov 2017

SWIFT: Surface Wave Instrument Float with Tracking

Record of Invention Number: 46566

Jim Thomson, Alex De Klerk, Joe Talbert

Disclosure

24 Jun 2013

Heave Place Mooring for Wave Energy Conversion (WEC) via Tension Changes

Record of Invention Number: 46558

Jim Thomson, Alex De Klerk, Joe Talbert

Disclosure

19 Jun 2013

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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