HomeProjectsPeopleToolsDownloadsPublicationsGalleryEducationLinks
  Home > Projects

ACTIVE PROJECTS



FOCUS AREAS:   Arctic  |  Meso/Submesoscale processes  |  Biophysical interaction

Arctic - current projects

An Annual Cycle of Atmosphere-Ice-Ocean Interactions using Autonomous Gliders and Moorings
OFFICE OF NAVAL RESEARCH (N00014-12-1-0180)
Craig Lee, Luc Rainville and Jason Gobat
Ice cover strongly modulates how atmospheric forcing imprints onto Arctic Ocean stratification and circulation. Differences in sea ice properties, including strength, mobility, open water fraction and bottom roughness, likely impact the transfer of momentum and buoyancy from atmosphere to ocean. Upper ocean vertical and horizontal structures also modulate the communication of atmospheric/ice forcing into the ocean interior. Year-round under-ice surveys conducted by Seagliders, combined with high‐resolution time series provided by three heavily-instrumented moorings, will be used to investigate the fate of atmospheric momentum and buoyancy input to the ice-ocean system. This unique set of observations will focus on the upper 200 m to quantify the dynamics governing mixed layer evolution, most of the internal wave spectrum, and mesoscale/submesoscale variability in the central Canada Basin. By siting in a region that experiences seasonal ice cover and persisting through an entire annual cycle, the proposed observing system will capture the interplay between atmosphere, ice and ocean over a broad range of atmospheric forcing and ice conditions. This provides the dynamic range required to advance our understanding of momentum and buoyancy transfer into the Arctic Ocean. MORE »

An Annual Cycle of Upper Ocean Salinity in a Rainfall–Dominated Region Captured by High-Resolution Glider Surveys
NASA
Luc Rainville, Craig M. Lee, Charles Eriksen, Kyla Druska
Contributing to both the Eulerian and Lagrangian components of the SPURS-2 field program, gliders are maintaining a persistent presence though a complete annual cycle, repeatedly occupying survey patterns to resolve the very near-­‐surface layer, mixed layer, and barrier layer. Over a pair of deployments covering an entire year, the main objectives of the SPURS Seaglider program are to:
  1. Resolve salinity, temperature, density, and their lateral gradients, in the top 1000 m of the water column on horizontal scales of ~20 km and time scales on the order of the inertial period (~3 days) near mooring sites(s).
  2. Provide direct estimates of turbulent dissipation in the mixed layer and in the sharp thermocline and halocline, via microstructure measurements.
  3. Provide gradients and turbulence estimates around freshwater patches as they are advected by the mean and mesoscale circulations, in combination with surface drifters or Lagrangian floats.
With these measurements, we will be able to resolve the salt storage and the horizontal and vertical advection of salt, and quantify diapycnal mixing of salt by small-scale turbulence around the mooring(s). This will provide a direct view of the processes by which the ocean spreads and integrates freshwater from precipitation. The proposed glider surveys will characterize the upper ocean in a consistent, reapeated manner at temporal and spatial scales that are well matched to the footprint and repeat cycle of the Aquarius salinity satellite. The year-long time series will capture an annual cycle to provide ample data for direct comparison with satellite measurements. These data will also be used to assess the ability (and limitations) of using remotely-­‐sensed measurements to quantify selected terms of the large-scale salinity budget. MORE »

Evolution of the Marginal Ice Zone: Adapting sampling with autonomous gliders
OFFICE OF NAVAL RESEARCH (N00014-12-1-0180)
Craig Lee, Luc Rainville and Jason Gobat
The spatial extent, thickness, and structure of Arctic sea ice cover are indelibly linked to the atmosphere and ocean. Seasonal and long-term changes in Arctic sea ice extent have profound impacts on the balance of processes controlling the ocean-ice-atmosphere system. Several positive feedback mechanisms, particularly for processes occurring near the marginal ice zone (MIZ), have the potential to amplify the seasonality of the Arctic.

As part of the ONR sponsored Marginal Ice Zone Departmental Research Initiative (DRI) An array of Seagliders will follow the retreating ice edge to document upper ocean structure and quantify the relative importance of processes that impact the ice-ocean boundary layer in and around the MIZ. Specifically, the glider program will:

  1. Collect observations that span open water, the MIZ and full ice-cover.
  2. Resolve the short temporal and spatial scales associated with key upper ocean processes.
  3. Quantify how the dominant upper ocean processes vary as a function of location relative to the MIZ.
  4. Measure turbulent mixing rates (via micro-temperature) in the upper water column.
  5. Measure multi-spectral downwelling irradiance in the upper water column.
  6. Provide high-resolution spatial context for other components of the DRI.
Gliders will work adaptively and complement the other components of the DRI. MORE »

A sustained observational network for Davis Strait - Understanding exchanges through a critical Arctic gateway
NATIONAL SCIENCE FOUNDATION (ARC0632231)
Craig M. Lee (UW), Jason Gobat (UW), Kathleen Stafford (UW), and Richard Moritz (UW)
As part of a coordinated international effort to quantify (and eventually monitor) the variability of fluxes connecting the Arctic and Atlantic Oceans and to understand the role played by the Arctic and sub-Arctic in steering decadal scale climate variability, an integrated observing system consisting of moorings and gliders will provide year-round measurements of volume, liquid freshwater and ice fluxes across Davis Strait. Fluxes through the Strait represent the net integrated Canadian Archipelago throughflow, modified by terrestrial inputs and oceanic processes during its southward transit through Baffin Bay. By the time they reach Davis Strait, Arctic waters already embody most of the transformation they undergo prior to exerting their influence on the deepwater formation sites in the Labrador Sea. This makes the Strait an ideal site for monitoring temporal and spatial variability in the critical upstream boundary condition for Labrador Sea convection. Measurements at Davis Strait will be used to study how fluctuations in the Arctic freshwater system modulate deep water formation to the south, thus influencing the associated meridional overturning circulation (MOC). MORE »

^ top  
Arctic - past projects

An Innovative Observational Network for Critical Arctic Gateways
NATIONAL SCIENCE FOUNDATION (ARC0632231)
Craig M. Lee (UW), Richard Moritz (UW), and Jason Gobat (UW)
As part of a coordinated international effort to quantify (and eventually monitor) the variability of fluxes connecting the Arctic and Atlantic Oceans and to understand the role played by the Arctic and sub-Arctic in steering decadal scale climate variability, an integrated observing system consisting of moorings and gliders will provide year-round measurements of volume, liquid freshwater and ice fluxes across Davis Strait. Fluxes through the Strait represent the net integrated Canadian Archipelago throughflow, modified by terrestrial inputs and oceanic processes during its southward transit through Baffin Bay. By the time they reach Davis Strait, Arctic waters already embody most of the transformation they undergo prior to exerting their influence on the deepwater formation sites in the Labrador Sea. This makes the Strait an ideal site for monitoring temporal and spatial variability in the critical upstream boundary condition for Labrador Sea convection. Measurements at Davis Strait will be used to study how fluctuations in the Arctic freshwater system modulate deep water formation to the south, thus influencing the associated meridional overturning circulation (MOC). MORE »

An Observational Array for High-Resolution, Year-Round Measurements of Volume, Freshwater and Ice Flux Variability in the Davis Strait
NATIONAL SCIENCE FOUNDATION (OPP0230381)
Craig M. Lee (UW), Richard Moritz (UW), Jason Gobat (UW), Brian Petrie (BIO) and Kenneth Drinkwater (BIO) principal investigators

A modular approach to building an Arctic Observing System for the IPY and beyond in the Switchyard region of the Arctic Ocean
NATIONAL SCIENCE FOUNDATION (ARC0633885)
Craig Lee (UW), Jason Gobat (UW), and Michael Steele (UW) principal investigators
Clarification of the nature of the observed changes in the Arctic Ocean is of central importance for development of capability to predict the future evolution of the Arctic system. Internally, more or less cyclical behavior of the system would have different effects compared to secular change with respect to: (1) water mass characteristics and their impact on stratification, diapycnal heat fluxes, and transport of heat and salt, (2) freshwater inventories (including that stored in form of sea ice), (3) freshwater release to the North Atlantic, (4) the heat budget of the upper water layers and its interplay with the sea ice cover, (5) sea ice circulation and thickness distribution, and (6) future circulation patterns. Externally, the nature of the change within the Arctic Ocean has implications for the preconditioning of the stratification in the water formation regions of NADW (constant addition of freshwater compared to freshwater addition that varies around an average value consistent with today’s conditions).

To address these and related questions we propose to design, where necessary develop, and implement a component of an Arctic Ocean Observing System in the Switchyard region of the Arctic Ocean (north of Greenland and Nares Strait) that will serve the scientific studies developed for the IPY (International Polar Year), SEARCH (Study of Environmental ARctic Change), and related programs. The defining elements of the System are: (1) a multi-platform design, (2) combination of proven technology with adaptation of innovative, highly promising, new tools for operation under sea ice cover that are considered to be future backbones of a quasi-permanent, pan-Arctic Ocean System, (3) a modular approach that allows expansion of the system to a pan-Arctic scale, and (4) ongoing refinement of the design through evaluation of combined data and modeling results. The project will leave a significant legacy through its contribution to a long-term pan-Arctic Ocean Observing System that will yield results on Arctic change well beyond the intensive IPY period.


An Annual Cycle of Upper Ocean Salinity Captured by High-Resolution Glider Surveys
NASA
Luc Rainville, Craig M. Lee, Charles Eriksen, Kyla Druska
We are using Seagliders to provide long-term and high-resolution measurements of the upper ocean in the SPURS region. Gliders maintain a persistent presence though a complete annual cycle, repeatedly occupying survey patterns to resolve the mixed layer and upper pycnocline. Over deployments lasting an entire year, the main objectives of the SPURS Seaglider program are to
  1. Resolve the salinity, temperature, density, and velocity fields in the upper 1000 m of the water column in 200 km by 200 km boxes centered on the two flux mooring sites, over temporal scales of 14 days and spatial scales of ~50 km.
  2. Measure the rates of turbulent dissipation in the thermocline and at the base of the mixed layer in the two 200 km by 200 km boxes. Mixing measurements will be made on all gliders sampling near the moorings (3 gliders each), to resolve vertical mixing term with the same temporal and spatial scales as for the scalar and velocity fields.
  3. Provide the large context of the two sites by repeating a long meridional section across the subtropical gyre and the salinity maximum. Two gliders will complete a full 1100-km section in one month or less.
With these measurements, we will be able to resolve the salt storage and the horizontal and vertical advection of salt, and quantify diapycnal mixing of salt by small-scale turbulence around the moorings, therefore providing a direct estimate of the main terms of the salt budgets in the mixed layer and in the whole upper ocean. The glider surveys characterize the upper ocean in a consistent, reapeatable manner at temporal and spatial scales that are well matched to the Aquarius footprint and repeat cycle. The year-long time series will capture an annual cycle to provide ample data for direct comparison with satellite measurements. These data will also be used to assess the ability (and limitations) of using remotely-­‐sensed measurements to quantify selected terms of the large-scale salinity budget. MORE »

Glider Surveys off Norway
Norwegian Meteorological Office
Craig Lee (UW) principal investigator
The northernmost limb of the Atlantic Meridional Overturning Circulation (AMOC), so relevant for understanding decadal climate variability, enters the Nordic Seas as the Norwegian Atlantic Current and continues on to recirculate in the Arctic Ocean. The strength of the Eastern Branch of the Norwegian Atlantic Current has been systematically monitored for over 15 years at the Svinøy section off southern Norway, whereas the strength of the Western Branch has not. We therefore used autonomous gliders to monitor and quantify the strength of this broader branch at the Svinøy section, located 500 km downstream from the Iceland–Scotland Ridge, and at the Station Mike section 300 km further downstream. The gliders' diving depth is 1000 m, spanning the warm Atlantic Water.

Workshop on Acoustic Navigation and Communications for High-latitude Ocean Research
NATIONAL SCIENCE FOUNDATION (OPP)
Craig M. Lee and Jason Gobat conveners
Recent community reports on autonomous and Lagrangian platforms and Arctic observing identify the development of under-ice navigation and telemetry technologies as one of the critical factors limiting the scope of high-latitude measurement efforts. An NSF-sponsored workshop will address these needs, bringing together international participants from the fields of acoustic navigation and telemetry, arctic oceanography, acoustical oceanography and autonomous platforms. Workshop participants will begin the coordinated definition of an acoustic navigation and telemetry system capable of supporting a diverse range of Arctic observational activities. Efforts will focus on comprehensive system design, including specifications for components comprised of mature technologies and identification of areas requiring additional development. MORE »
logo

North Atlantic Bloom Experiment
NATIONAL SCIENCE FOUNDATION (OCE0627379)
Craig Lee (UW), Eric D'Asaro (UW), and Mary Jane Perry (U. Maine) principal investigators

Mixed Layer Model Testing (AESOP)
OFFICE OF NAVAL RESEARCH (N00014-05-1-0331)
Craig Lee (UW) and Eric D'Asaro (UW) principal investigators

Physical and Optical Structures in the Upper Ocean of the East (Japan) Sea
OFFICE OF NAVAL RESEARCH (N00014-98-1-0370)
Craig M. Lee (UW), Kenneth H. Brink (WHOI) and Burton H. Jones (USC), principal investigators
logo

Physical and Optical Structures in the Upper Ocean of the East (Japan) Sea
OFFICE OF NAVAL RESEARCH (N00014-98-1-0370)
Craig M. Lee (UW), Kenneth H. Brink (WHOI) and Burton H. Jones (USC), principal investigators
logo

DOLCE VITA - Mesoscale Dynamics and Response to Strong Atmospheric Forcing
OFFICE OF NAVAL RESEARCH (N00014-02-1-0064)
Craig M. Lee (UW), principal investigator
Recent ONR-funded investigations have focused on regions bounded by progressively more complex topography (e.g. Arabian Sea, Japan/East Sea and Adriatic Sea) where orographic effects produce intense, small-scale atmospheric forcing. Small-scale wind- and buoyancy-forcing, combined with riverine input, complex bathymetry and proximity to the coastal boundary, support a wide variety of energetic fronts, filaments and eddies. These features have short temporal and spatial scales and can play critical roles in governing basin-scale circulation, cross-shelf transport, watermass transformation and subduction. Two cruises in the Northern and Central Adriatic Sea conducted quasi-synoptic, three-dimensional surveys of mesocale and submesoscale physical and optical variability, following their response to strong forcing events. During winter (February), sampling emphasized the response to episodic Bora wind events. Although springtime (May) measurement program was designed to sample during the Po River spring freshette, freshwater discharge rates were more than a standard deviation below the 12-year mean and winds remained weak throughout the survey period, leading to a study of weakly forced dynamics in a strongly stratified, shallow water regime. MORE »
logo

DOLCE VITA - Mesoscale Dynamics and Response to Strong Atmospheric Forcing
OFFICE OF NAVAL RESEARCH (N00014-02-1-0064)
Craig M. Lee (UW), principal investigator
Recent ONR-funded investigations have focused on regions bounded by progressively more complex topography (e.g. Arabian Sea, Japan/East Sea and Adriatic Sea) where orographic effects produce intense, small-scale atmospheric forcing. Small-scale wind- and buoyancy-forcing, combined with riverine input, complex bathymetry and proximity to the coastal boundary, support a wide variety of energetic fronts, filaments and eddies. These features have short temporal and spatial scales and can play critical roles in governing basin-scale circulation, cross-shelf transport, watermass transformation and subduction. Two cruises in the Northern and Central Adriatic Sea conducted quasi-synoptic, three-dimensional surveys of mesocale and submesoscale physical and optical variability, following their response to strong forcing events. During winter (February), sampling emphasized the response to episodic Bora wind events. Although springtime (May) measurement program was designed to sample during the Po River spring freshette, freshwater discharge rates were more than a standard deviation below the 12-year mean and winds remained weak throughout the survey period, leading to a study of weakly forced dynamics in a strongly stratified, shallow water regime. MORE »
logo

Shallow Water Climatology
OFFICE OF NAVAL RESEARCH (N00014-02-1-0135)
Craig M. Lee (UW), principal investigator

A High-Performance, Shallow-Water Towed Profiler for Intensive, Three-Dimensional Surveys
DURIP - OFFICE OF NAVAL RESEARCH (N00014-01-1-0436), 2001 - 2003
Craig M. Lee (UW), principal investigator

Seasonal and Interannual Variability of the Alaska Coastal Current: Long-Term, Three-Dimensional Observations using a Telemetering, Autonomous Vehicle
NATIONAL SCIENCE FOUNDATION (OCE0107946), NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION AND OFFICE OF NAVAL RESEARCH (N00014-01-1-1016)
Craig M. Lee (UW) and Charles C. Eriksen (UW), principal investigators
As part of the U.S. GLOBEC Northeast Pacific program, repeated Seaglider surveys will characterize the seasonal and interannual variability of the Alaska coastal Current (ACC). The dynamics of the Alaska Coastal Current (ACC) govern stratification and circulation over the inner portion of the Alaskan shelf, a region that plays a critical role in the early life history of several commercially important fish species, including juvenile salmon. The system responds strongly to large seasonal and interannual changes in freshwater discharge and wind-forcing. Moreover, seasonal shifts in dynamics likely exert strong influences on the temporal and spatial structure of stratification, on the spring phytoplankton bloom and on the advective transport of zooplankton and fish. Seasonal cycles in dynamics may also play a key role in explaining how nutrients are replenished in this downwelling-favorable system that is inundated by nutrient-depleted freshwater discharge. Thus, variability in wind-forcing and freshwater discharge produce significant changes in ACC dynamics which can influence the recruitment success of zooplankton and fish through a number of different pathways. MORE »
logo

U.S. GLOBEC Georges Bank Phase 2: Retention Processes - Moorings and Highly Resolved Hydrography
NATIONAL SCIENCE FOUNDATION, 1996 - 1998
Kenneth H. Brink (WHOI) and Craig Lee (UW)
logo

U.S. GLOBEC Georges Bank Phase 2: Retention Processes - Moorings and Highly Resolved Hydrography
NATIONAL SCIENCE FOUNDATION, 1996 - 1998
Kenneth H. Brink (WHOI) and Craig Lee (UW)
logo

Arabian Sea Response to Monsoon Forcing
OFFICE OF NAVAL RESEARCH (N00014-94-1-0226), 1994 - 1998
Kenneth Brink (WHOI), principal investigator (Kenneth H. Brink (WHOI), Craig M. Lee (WHOI), Burton H. Jones (USC) and Albert S. Fischer (WHOI))

Arabian Sea Response to Monsoonal Forcing
FULBRIGHT FOUNDATION AND UW SCHOOL OF OCEANOGRAPHY
Abdullah Bamasoud (UW), Craig M. Lee (UW) and Kathie Kelly (UW)

Glider Repeat Surveys of Eastern Boundary Currents off Washington
NATIONAL SCIENCE FOUNDATION (OCE00955414)
Charles C. Eriksen (UW) and Craig M. Lee (UW), principal investigators
The West Wind Drift feeds both the California and Alaska Currents, providing a pathway for exchange between the subarctic and subtropical gyres. Its bifurcation at the eastern boundary is known qualitatively but not particularly quantitatively. The relative proportions of waters returning poleward and those continuing equatorward is a matter of speculation due to a relatively sparse observational base incapable of resolving the space-time structure of the eastern boundary current formation. Seasonal and interannual changes in stratification in a broad region off the Pacific Northwest coast are recognized, but their causes and links to flow variation are largely unknown. Seagliders will operate year-round, occupying repeated hydrographic sections across the northern reaches of the California Current system. These measurements will characterize the seasonal evolution of the eastern boundary current system off the Washington coast.

Hawaiian Ocean Mixing Experiment: Nearfield: Full Depth Tide Beam Tracking
NATIONAL SCIENCE FOUNDATION (OCE9819536)
Thomas B. Sanford (UW), Craig M. Lee (UW) and Eric Kunze (UW), principal investigators

Hawaiian Ocean Mixing Experiment: Survey: A Full Depth Census of Tide-Topography Interactions
NATIONAL SCIENCE FOUNDATION (OCE9819537)
Thomas B. Sanford (UW), Craig M. Lee (UW) and Eric Kunze (UW), principal investigators

^ top