Dr Yueng-Djern Lenn

Reader in Physical Oceanography

View Dr Yueng-Djern Lenn’s profile on the Bangor Research Portal

Additional Contact Information

311 Craig Mair

School of Ocean Sciences

Bangor University, Wales

Menai Bridge LL59 5AB

tel:+44 1248388658

e-mail:y.lenn AT bangor.ac.uk

I am a polar physical oceanographer and my interests lie in understanding the physical processes integral to ocean overturning that impact climate in the polar oceans. My Southern Ocean research has focused on Drake Passage eddy heat and momentum fluxes, the surface Ekman layer that constitute the upper limb of the overturning circulation, and diapycnal mixing driving water mass transformation in the thermocline at the Antarctic continental slope. My Arctic research focuses on water mass transformations occurring in the continental shelf seas and along the Arctic continental slope that link the Arctic to the global overturning circulation, most recently investigating the role of different mixing mechanisms (i.e. double diffusion and turbulent mixing drive by tides or winds) in fluxing heat and other properties from the warm Atlantic Water into overlying Arctic halocline and mixed layer.

I am also the schools liason for the School of Ocean Sciences, co-ordinating most school visits to Ocean Sciences by schools as well as providing support for colleagues who visit schools. Other outreach events I support include school STEM Careers Fairs and other Science Fairs. These activities include events organised in partnership with STEMCymru and other similar organisations seeking to promote STEM in Wales and beyond.

Research Area:

Ocean Physics

Qualifications

PhD: Observations of Antarctic Circumpolar Current Dynamics and Small-scale variability near the Antarctic peninsula
Scripps Institution of Oceanography, La Jolla, 2006
MSc: Medical Radiation Physics
University College London, 1998
MA: EXPERIMENTAL AND THEORETICAL PHYSICS
Cambridge University, 1997

Teaching and Supervision

Current Phd Students: Ben Barton, Universite de Bretagne Occidentale

Current modules:

ONS1001: Environmental Data & Analysis

DXX1005: Earth Systems & Processes

OSX1005: Introducing the Oceans

OSX2005: Earth and Ocean Observation

OSX2006: TIdes, Waves & Sampling

OSX3002: Marine Ecosystems & Processes

OSX4010: Key Concepts & Techniques

OSX4012: Practical Oceanography

OSX4015: Climate & Climate Change

OSX4408: Field and Lab Oceanography

Postgraduate Project Opportunities

The PhD projects I propose usually stem from my current research interests and focus mainly on processes that drive fluxes of heat, freshwater and momentum within the polar ocean and between the ocean, cryosphere and atmosphere. Past students have studied how tidal forcing drives vertical fluxes of heat from Upper Circumpolar Deep Water into the surrounding colder fresher Antarctic-source waters along the Antarctic Peninsular continental slope, as welll as how warm Atlantic Water is contributing to sea ice loss in the Arctic Barents Sea. I have also supervised projects studying wind-driven mixing at the base of the open ocean mixed-layer and the role of wind-forcing in driving Arctic mixing.

Publications

2022

PublishedEddies and the distribution of Eddy Kinetic Energy in the Arctic Ocean
von Appen, W., Baumann, T. M., Janout, M., Koldunov, N., Lenn, Y-D., Pickart, R., Scott, R. & Wang, Q., 27 Apr 2022, In: Oceanography. 35, 2
Research output: Contribution to journal › Article › peer-review
PublishedImpact of acoustic Doppler current profiler (ADCP) motion on structure function estimates of turbulent kinetic energy dissipation rate
Scannell, B., Lenn, Y-D. & Rippeth, T., 3 Feb 2022, In: Ocean Science. 18, 1, p. 169–192
Research output: Contribution to journal › Article › peer-review
PublishedIncreasing nutrient fluxes and mixing regime changes in the eastern Arctic Ocean
Shultz, K., Lincoln, B., Povazhnyy, V., Rippeth, T., Lenn, Y-D., Janout, M., Alkire, M., Scannell, B. & Torres-Valdes, S., 16 Mar 2022, In: Geophysical Research Letters. 49, 5, e2021GL096152.
Research output: Contribution to journal › Article › peer-review

2021

PublishedA warm Jet in a cold ocean
MacKinnon, J., Lenn, Y-D., Simmons, H. L., Hargrove, J., Thomson, J., Peacock, T., Alford, M. H., Barton, B. I., Boury, S., Brenner, S. D., Couto, N., Danielson, S. L., Fine, E. C., Graber, H. C., Guthrie, J., Hopkins, J. E., Jayne, S. R., Jeon, C., Klenz, T., Lee, C. M., Lucas, A. J., Lund, B., Mahaffey, C., Norman, L., Rainville, L., Smith, M. M., Thomas, L. N., Torres-Valdes, S. & Wood, K. R., 23 Apr 2021, In: Nature Communications. 12, 1, p. 2418
Research output: Contribution to journal › Article › peer-review
PublishedOn the Along-Slope Heat Loss of the Boundary Current in the Eastern Arctic Ocean
Schulz, K., Janout, M. A., Lenn, Y-D., Castillo, E. R., Polyakov, I., Mohrholz, V., Tippenhauer, S., Reeve, K., Holemann, J., Rabe, B. & Vredenborg, M., Feb 2021, In: Journal of Geophysical Research: Oceans. 126, 2, e2020JC016375.
Research output: Contribution to journal › Article › peer-review

2020

PublishedWater mass properties derived from satellite observations in the Barents Sea
Barton, B., Lique, C. & Lenn, Y-D., Aug 2020, In: Journal of Geophysical Research: Oceans. 125, 8, e2019JC015449.
Research output: Contribution to journal › Article › peer-review

2019

PublishedEastern Arctic Ocean diapycnal heat fluxes through large double-diffusive steps
Polyakov, I. V., Padman, L., Lenn, Y-D., Pnyushkov, A., Rember, R. & Ivanov, V. V., 4 Jan 2019, In: Journal of Physical Oceanography. 49, 1, p. 227-246
Research output: Contribution to journal › Article › peer-review
PublishedOn the Future of Argo: A Global, Full-Depth, Multi-Disciplinary Array
Roemmich, D., Alford, M. H., Claustre, H., Johnson, K., King, B., Moum, J., Oke, P., Owens, W. B., Pouliquen, S., Purkey, S., Scanderbeg, M., Suga, T., Wijffels, S., Zilberman, N., Bakker, D., Baringer, M., Belbeoch, M., Bittig, H. C., Boss, E., Calil, P., Carse, F., Carval, T., Chai, F., Conchubhair, D. Ó., d’Ortenzio, F., Dall’Olmo, G., Desbruyeres, D., Fennel, K., Fer, I., Ferrari, R., Forget, G., Freeland, H., Fujiki, T., Gehlen, M., Greenan, B., Hallberg, R., Hibiya, T., Hosoda, S., Jayne, S., Jochum, M., Johnson, G. C., Kang, K., Kolodziejczyk, N., Körtzinger, A., Traon, P-Y. L., Lenn, Y-D., Maze, G., Mork, K. A., Morris, T., Nagai, T., Nash, J., Garabato, A. N., Olsen, A., Pattabhi, R. R., Prakash, S., Riser, S., Schmechtig, C., Schmid, C., Shroyer, E., Sterl, A., Sutton, P., Talley, L., Tanhua, T., Thierry, V., Thomalla, S., Toole, J., Troisi, A., Trull, T. W., Turton, J., Velez-Belchi, P. J., Walczowski, W., Wang, H., Wanninkhof, R., Waterhouse, A. F., Waterman, S., Watson, A., Wilson, C., Wong, A. P. S., Xu, J. & Yasuda, I., 2 Aug 2019, In: Frontiers in Marine Science. 6, 439
Research output: Contribution to journal › Article › peer-review
PublishedThe Increasing Prevalence of High Frequency Internal Waves in an Arctic Ocean With Declining Sea Ice Cover
Rippeth, T., Vlasenko, V., Stashchuk, N., Koslov, I., Scannell, B., Green, M., Lincoln, B. & Lenn, Y-D., 11 Nov 2019, ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, OMAE2019-96621
Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › peer-review

2018

PublishedObserved atlantification of the Barents Sea causes the Polar Front to limit the expansion of winter sea ice
Barton, B., Lenn, Y-D. & Lique, C., 15 Aug 2018, In: Journal of Physical Oceanography.
Research output: Contribution to journal › Article › peer-review

2016

PublishedWind-driven mixing at intermediate depths in an ice-free Arctic Ocean
Lincoln, B., Rippeth, T., Lenn, Y-D., Timmermans, M-L., Willaims, W. & Bacon, S., 28 Sep 2016, In: Geophysical Research Letters. 43, 18, p. 9749-9756
Research output: Contribution to journal › Article › peer-review

2015

PublishedKara Sea freshwater transport through Vilkitsky Strait: Variability, forcing, and further pathways toward the western Arctic Ocean from a model and observations
Janout, M. A., Aksenov, Y., Holemann, J. A., Rabe, B., Schauer, U., Polyakov, I. V., Bacon, S., Coward, A. C., Karcher, M., Lenn, Y., Kassens, H. & Timokhov, L., 18 Jul 2015, In: Journal of Geophysical Research: Oceans. 120, 7, p. 4925-4944
Research output: Contribution to journal › Article › peer-review
PublishedTide-mediated warming of Arctic halocline by Atlantic heat fluxes over rough topography
Rippeth, T. P., Lincoln, B. J., Lenn, Y. D., Green, J. A., Sundfjord, A. & Bacon, S., Mar 2015, In: Nature Geoscience. 8, 3, p. 191-194
Research output: Contribution to journal › Article › peer-review

2014

PublishedObservations of a diapycnal shortcut to adiabatic upwelling of Antarctic Circumpolar Deep Water
Silvester, J. M., Lenn, Y. D., Polton, J. A., Rippeth, T. P. & Maqueda, M. M., 25 Nov 2014, In: Geophysical Research Letters. 41, 22, p. 7950-7956
Research output: Contribution to journal › Article › peer-review
PublishedSemidiurnal Tides on the Laptev Sea Shelf with Implications for Shear and Vertical Mixing
Janout, M. A. & Lenn, Y. D., 8 Jan 2014, In: Journal of Physical Oceanography. 44, 1, p. 202-219
Research output: Contribution to journal › Article › peer-review

2013

PublishedCan Drake Passage Observations Match Ekman's Classic Theory?
Polton, J. A., Lenn, Y., Elipot, S., Chereskin, T. K. & Sprintall, J., 1 Aug 2013, In: Journal of Physical Oceanography. 43, 8, p. 1733-1740
Research output: Contribution to journal › Article › peer-review
PublishedShear at the Base of the Oceanic Mixed Layer Generated by Wind Shear Alignment
Brannigan, L., Lenn, Y. D., Rippeth, T. P., McDonough, E., Chereskin, T. K. & Sprintall, J., 1 Aug 2013, In: Journal of Physical Oceanography. 43, 8, p. 1798-1810
Research output: Contribution to journal › Article › peer-review

2012

PublishedMooring-Based Observations of Double-Diffusive Staircases over the Laptev Sea Slope
Polyakov, I. V., Pnyushkov, A. V., Rember, R., Ivanov, V. V., Lenn, Y. D., Padman, L. & Carmack, E. C., 1 Jan 2012, In: Journal of Physical Oceanography. 42, 1, p. 95-109
Research output: Contribution to journal › Article › peer-review

2011

PublishedIntermittent intense turbulent mixing under ice in the Laptev Sea continental shelf.
Lenn, Y., Rippeth, T. P., Old, C., Bacon, S., Polyakov, I., Ivanov, V. & Holemann, J., 1 Mar 2011, In: Journal of Physical Oceanography. 41, 3, p. 531-547
Research output: Contribution to journal › Article › peer-review
PublishedNear-Surface Eddy Heat and Momentum Fluxes in the Antarctic Circumpolar Current in Drake Passag
Lenn, Y-D., Chereskin, T., Sprintall, J. & McClean, J., 1 Jul 2011, In: Journal of Physical Oceanography. 41, 7, p. 1385-1407
Research output: Contribution to journal › Article › peer-review

2009

PublishedObservations of Ekman currents in the southern ocean.
Lenn, Y. D. & Chereskin, T. K., 1 Mar 2009, In: Journal of Physical Oceanography. 39, 3, p. 768-779
Research output: Contribution to journal › Article › peer-review
PublishedVertical mixing at intermediate depths in the Arctic boundary current.
Lenn, Y. D., Wiles, P. J., Torres-Valdes, S., Abrahamsen, E. P., Rippeth, T. P., Simpson, J. H., Bacon, S., Laxon, S. W., Polyakov, I., Ivanov, V. & Kirillov, S., 3 Mar 2009, In: Geophysical Research Letters. 36, p. L05601
Research output: Contribution to journal › Article › peer-review

2008

PublishedImproving estimates of the Antarctic circumpolar current streamlines in Drake Passage.
Lenn, Y. D., Chereskin, T. K. & Sprintall, J., 1 May 2008, In: Journal of Physical Oceanography. 38, 5, p. 1000-1010
Research output: Contribution to journal › Article › peer-review

2007

PublishedMean Jets, mesoscale variability and eddy momentum fluxes in the surface layer of the Antarctic Circumpolar Current in Drake Passage
Lenn, Y-D., Chereskin, T., Sprintall, J. & Firing, E., 1 Jan 2007, In: Journal of Marine Research. 65, 1, p. 27 58 p.
Research output: Contribution to journal › Article › peer-review

Activities

2020

ATOMIX working group (External organisation)
Funded by the Scientific Committee on Ocean Research to chair the Analysing ocean turbulence observations to quantify mixing (ATOMIX) working group
1 Jan 2020 – 12 Dec 2020
Links:
- https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fscor-int.org%2Fgroup%2Fanalysing-ocean-turbulence-observations-to-quantify-mixing-atomix%2F&data=04%7C01%7Cm.walker%40bangor.ac.uk%7C97d45e6ad9b94f42625b08d8e48390c2%7Cc6474c55a9234d2a9bd4ece37148dbb2%7C0%7C0%7C637510601000596036%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=e1AG5aPNLa3ozTESiavLvbwrm2a6Wn0rTMgyShLnwvU%3D&reserved=0
Activity: Membership of board (Chair)

2019

Arctic Mixing Workshop
16 Oct 2019 – 18 Oct 2019
Activity: Participation in workshop, seminar, course (Speaker)

Projects

Quantifying inter-ocean fluxes in the Cape Cauldron of high EKE (QUICCHE)

01/05/2022 – 31/05/2027 (Active)
ArctiCONNECT

14/11/2020 – 13/12/2023 (Active)
Primary productivity driven by escalating nutrient fluxes?

01/07/2018 – 28/05/2022 (Finished)
IIGLOOS: Interactions at the interface of glaciology, oceanography and sea ice

01/05/2016 – 01/08/2017 (Finished)
Understanding the Arctic continental shelf mixing regimes and their impact on shelf sea-circulation and upper ocean stratification

01/09/2010 – 05/09/2016 (Finished)

Other Grants and Projects

2018-2021 NERC Changing Arctic Ocean: Primary productivity driven by escalating Arctic nutrient fluxes? (Lead Principle Investigator, Lenn)

2010-2015 NERC Postdoctoral Fellowship Principle Investigator

2011-2016 TEA-COSI:The Environment of the Arctic: Climate, Ocean and Sea-Ice UK NERC Consortium: Including Lenn (Project Partner, Bangor.)

2012-2015 Upper ocean heat flux in the Eurasian Basin: Oceanic thermodynamic forcing contributing to Arctic ice loss. USA National Science Foundation grant including Lenn (Project Partner, Bangor)