APL-UW Home

Jobs
About
Campus Map
Contact
Privacy
Intranet

Craig Lee

Senior Principal Oceanographer

Professor, Oceanography

Email

craig@apl.washington.edu

Phone

206-685-7656

Research Interests

Upper Ocean Dynamics, Coastal Ocean Processes, Internal Waves, Fronts, Dynamics and Biological Process Interactions

Biosketch

Dr. Lee is a physical oceanographer specializing in observations and instrument development. His primary scientific interests include: (1) upper ocean dynamics, especially mesoscale and submesocale fronts and eddies, (2) interactions between biology, biogeochemistry and ocean physics and (3) high-latitude oceanography.

With partner Dr. Jason Gobat, Lee founded and leads a team of scientists and technologists that pursues a wide range of oceanographic field programs, including intensive studies of the Kuroshio Current, coupled physical–biogeochemical studies such as the recent patch-scale investigation of the North Atlantic spring phytoplankton bloom and studies aimed at quantifying and understanding Arctic change. An important component of this work involves identifying advances that could be achieved through novel measurements and developing new instruments to meet these needs.

The team's accomplishments include autonomous gliders capable of extended operation in ice-covered waters, high-performance towed vehicles and light-weight, inexpensive mooring technologies. The team also pursues K-12 educational outreach and routinely employs undergraduate research assistants. Within the community, Lee provides leadership through service on the science steering committees for several large research programs and by serving on and chairing advisory panels for U.S. Arctic efforts. Lee supports and advises masters and doctoral students and teaches graduate level courses on observations of ocean circulation and instruments, methods and experimental design.

Department Affiliation

Ocean Physics

Education

B.S. Electrical Engineering and Computer Science, University of California, Berkeley, 1987

Ph.D. Physical Oceanography, University of Washington, 1995

Projects

Stratified Ocean Dynamics of the Arctic — SODA

More Info

31 Oct 2016

Vertical and lateral water properties and density structure with the Arctic Ocean are intimately related to the ocean circulation, and have profound consequences for sea ice growth and retreat as well as for prpagation of acoustic energy at all scales. Our current understanding of the dynamics governing arctic upper ocean stratification and circulation derives largely from a period when extensive ice cover modulated the oceanic response to atmospheric forcing. Recently, however, there has been significant arctic warming, accompanied by changes in the extent, thickness distribution, and properties of the arctic sea ice cover. The need to understand these changes and their impact on arctic stratification and circulation, sea ice evolution, and the acoustic environment motivate this initiative.

The Submesoscale Cascade in the South China Sea

This research program is investigating the evolution of submesoscale eddies and filaments in the Kuroshio-influenced region off the southwest coast of Taiwan.

More Info

26 Aug 2015

Science questions:
1. What role does the Kuroshio play in generating mesoscale and submesoscale variability modeled/observed off the SW coast of Taiwan?
2. How does this vary with atmospheric forcing?
3. How do these features evolve in response to wintertime (strong) atmospheric forcing?
4. What role do these dynamics play in driving water mass evolution and interior stratification in the South China Sea?
5. What role do these dynamics/features have on the transition of water masses from northern SCS water into the Kuroshio branch water/current and local flow patterns?

Salinity Processes in the Upper Ocean Regional Study — SPURS

The NASA SPURS research effort is actively addressing the essential role of the ocean in the global water cycle by measuring salinity and accumulating other data to improve our basic understanding of the ocean's water cycle and its ties to climate.

15 Apr 2015

More Projects

Videos

EXPORTS: Export Processes in the Ocean from RemoTe Sensing

The EXPORTS mission is to quantify how much of the atmospheric carbon dioxide fixed during primary production near the ocean surface is pumped to the deep twilight zone by biological processes, where it can be sequestered for months to millennia.

An integrated observation strategy leverages the precise, intense measurements made on ships, the persistent subsurface data collected by swimming and floating robots, and the global surface views provided by satellites.

18 Sep 2018

Eddies Drive Particulate Carbon Deep in the Ocean During the North Atlantic Spring Bloom

The swirling eddies that create patches of stratification to hold phytoplankton near the sunlit surface during the North Atlantic spring bloom, also inject the floating organic carbon particles deep into the ocean. The finding, reported in Science, has important implications for the ocean's role in the carbon cycle on Earth: phytoplankton use carbon dioxide absorbed by the ocean from the atmosphere during the bloom and the resulting organic carbon near the sea surface is sequestered in the deep ocean.

27 Mar 2015

Seaglider: Autonomous Undersea Vehicle

APL-UW scientists continually expand Seaglider's hardware/software systems, and sensor packages. First developed for oceanographic research, it is also used by the U.S. Navy to detect and monitor marine mammals. Recently, the manufacture and marketing of Seaglider has been licensed to Kongsberg Underwater Technology, Inc., which will push the vehicle to emerging markets in offshore environmental monitoring for the oil and gas industry.

14 Aug 2013

More Videos

Publications

2000-present and while at APL-UW

Subannual and seasonal variability of Atlantic-origin waters in two adjacent West Greenland fjords

Carroll, D., D.A. Sutherland, B. Curry, J.D. Nash, E.L. Shroyer, G.A. Catania, L.A. Stearns, J.P. Grist, C.M. Lee, and L. de Steur, "Subannual and seasonal variability of Atlantic-origin waters in two adjacent West Greenland fjords," J. Geophys. Res., 123, 6670-6687, doi:10.1029/2018JC014278, 2018.

More Info

1 Sep 2018

Greenland fjords provide a pathway for the inflow of warm shelf waters to glacier termini and outflow of glacially modified waters to the coastal ocean. Characterizing the dominant modes of variability in fjord circulation, and how they vary over subannual and seasonal time scales, is critical for predicting ocean heat transport to the ice. Here we present a 2‐year hydrographic record from a suite of moorings in Davis Strait and two neighboring west Greenland fjords that exhibit contrasting fjord and glacier geometry (Kangerdlugssuaq Sermerssua and Rink Isbrae). Hydrographic variability above the sill exhibits clear seasonality, with a progressive cooling of near‐surface waters and shoaling of deep isotherms above the sill during winter to spring. Renewal of below‐sill waters coincides with the arrival of dense waters at the fjord mouth; warm, salty Atlantic‐origin water cascades into fjord basins from winter to midsummer. We then use Seaglider observations at Davis Strait, along with reanalysis of sea ice and wind stress in Baffin Bay, to explore the role of the West Greenland Current and local air‐sea forcing in driving fjord renewal. These results demonstrate the importance of both remote and local processes in driving renewal of near‐terminus waters, highlighting the need for sustained observations and improved ocean models that resolve the complete slope‐trough‐fjord‐ice system.

Internal waves in the Arctic: Influence of ice concentration, ice roughness, and surface layer stratification

Cole, S.T., J.M. Toole, L. Rainville, and C.M. Lee, "Internal waves in the Arctic: Influence of ice concentration, ice roughness, and surface layer stratification," J. Geophys. Res., 123, 5571-5586, doi:10.1029/2018JC014096, 2018.

More Info

1 Aug 2018

The Arctic ice cover influences the generation, propagation, and dissipation of internal waves, which in turn may affect vertical mixing in the ocean interior. The Arctic internal wavefield and its relationship to the ice cover is investigated using observations from Ice‐Tethered Profilers with Velocity and Seaglider sampling during the 2014 Marginal Ice Zone experiment in the Canada Basin. Ice roughness, ice concentration, and wind forcing all influenced the daily to seasonal changes in the internal wavefield. Three different ice concentration thresholds appeared to determine the evolution of internal wave spectral energy levels: (1) the initial decrease from 100% ice concentration after which dissipation during the surface reflection was inferred to increase, (2) the transition to 70–80% ice concentration when the local generation of internal waves increased, and (3) the transition to open water that was associated with larger‐amplitude internal waves. Ice roughness influenced internal wave properties for ice concentrations greater than approximately 70–80%: smoother ice was associated with reduced local internal wave generation. Richardson numbers were rarely supercritical, consistent with weak vertical mixing under all ice concentrations. On decadal timescales, smoother ice may counteract the effects of lower ice concentration on the internal wavefield complicating future predictions of internal wave activity and vertical mixing.

A multi-method autonomous assessment of primary productivity and export efficiency in the springtime North Atlantic

Briggs, N., K. Guðmundsson, I. Cetinić, E. D'Asaro, E. Rehm, C. Lee, and M.J. Perry, "A multi-method autonomous assessment of primary productivity and export efficiency in the springtime North Atlantic," Biogeiosciences, 15, 4515-4532, doi:10.5194/bg-15-4515-2018, 2018.

More Info

25 Jul 2018

Fixation of organic carbon by phytoplankton is the foundation of nearly all open-ocean ecosystems and a critical part of the global carbon cycle. But the quantification and validation of ocean primary productivity at large scale remains a major challenge due to limited coverage of ship-based measurements and the difficulty of validating diverse measurement techniques. Accurate primary productivity measurements from autonomous platforms would be highly desirable due to much greater potential coverage. In pursuit of this goal we estimate gross primary productivity over 2 months in the springtime North Atlantic from an autonomous Lagrangian float using diel cycles of particulate organic carbon derived from optical beam attenuation. We test method precision and accuracy by comparison against entirely independent estimates from a locally parameterized model based on chlorophyll a and light measurements from the same float. During nutrient-replete conditions (80% of the study period), we obtain strong relative agreement between the independent methods across an order of magnitude of productivities (r2 = 0.97), with slight underestimation by the diel cycle method (–19±5%). At the end of the diatom bloom, this relative difference increases to –58% for a 6-day period, likely a response to SiO4 limitation, which is not included in the model. In addition, we estimate gross oxygen productivity from O2 diel cycles and find strong correlation with diel-cycle-based gross primary productivity over the entire deployment, providing further qualitative support for both methods. Finally, simultaneous estimates of net community productivity, carbon export, and particle size suggest that bloom growth is halted by a combination of reduced productivity due to SiO4 limitation and increased export efficiency due to rapid aggregation. After the diatom bloom, high Chl a-normalized productivity indicates that low net growth during this period is due to increased heterotrophic respiration and not nutrient limitation. These findings represent a significant advance in the accuracy and completeness of upper-ocean carbon cycle measurements from an autonomous platform.

More Publications

In The News

NASA, NSF expedition to study ocean carbon embarks in August from Seattle

UW News, Hannah Hickey

Dozens of scientists, as well as underwater drones and other high-tech ocean instruments, will set sail from Seattle in mid-August. Funded by NASA and the National Science Foundation, the team will study the life and death of the small organisms that play a critical role in removing carbon dioxide from the atmosphere, and in the ocean’s carbon cycle.

21 Jun 2018

Underwater robots to measure Antarctica climate threat

CNN, Lynda Kinkade and Shelby Rose

Scientists with the University of Washington in conjunction with Paul G. Allen Philanthropies are sending robots to Antarctica for as long as a year in what will be the longest mission ever undertaken in the region. Seagliders and profiling floats will focus on Pine Island Glacier in West Antarctica, the continent's fastest-melting ice sheet. The aim: to gain more extensive data about the rate of ice loss and thus more accurately predict future sea level rise.

27 Jan 2018

Ice-diving drones embark on risky Antarctic mission

Scientific American, Mark Harris

To forecast sea level rise, a flotilla of undersea robots must map the unseen bottom of a melting ice shelf — if they are not sunk by it.

6 Dec 2017

More News Items

Inventions

Ogive Fairing, Cover Hatch, and Wing Drawings

Record of Invention Number: 4149-Reg-0009

Jason Gobat, Adam Huxtable, Craig Lee, Charles Eriksen, Jim Osse

Disclosure

25 Mar 2010

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
Close

 

Close