Author Archives: Anne-Sophie Fortin

Postdoctoral position in deep circulation and AMOC variability in the subpolar North Atlantic

We are seeking a highly motivated physical oceanographer for a postdoctoral position at Woods Hole Oceanographic Institution. The postdoc will work with a team of researchers on “Overturning in the Subpolar North Atlantic Program (OSNAP)”, the over-arching goal of which is to observe and understand the drivers of monthly-to-interannual variability in meridional fluxes of volume, heat and freshwater at subpolar latitudes in the North Atlantic.

The candidate should have experience in one or more of the following: analysis of moored current and temperature/salinity (T/S) observations, analysis of Lagrangian observations, and use of numerical model output with observations to build understanding of the relevant dynamics. Experience combining the above with other observational data sets (e.g., satellite altimetry and hydrography) to gain deeper understanding of the underlying physics is preferred. Expertise in meso-scale and large-scale ocean dynamics, and demonstration of completed research submitted or published in peer-reviewed journals is required.

The successful candidate will focus primarily on the analysis of a growing time series (2014-2024) from a transport-resolving current meter and T/S moored array in the Irminger Basin east of Greenland to develop a better understanding of the drivers of variability in transport and water properties of the Deep Western Boundary Current. A rich Lagrangian data set of deep acoustically tracked float trajectories, and observations from the Ocean Observatories Initiative’s Global Irminger Sea Array are also available to complement the moored observations. The postdoc is expected to include dynamical models as well as numerical model output where appropriate to extend the interpretation of the observations. There are many collaboration opportunities, with the OSNAP PIs at WHOI as well as with the U.S. and international OSNAP community virtually and at workshops. Further details of the research undertaken by the successful candidate will be determined by mutual agreement according to their experience and interests.

Additional information and instructions for applying can be found here:—po/job?hub=8&_gl=1*h75bqe*_ga*Mjk1ODg4MDQwLjE3MDk1NzExMjA.*_ga_5Y2BYGL910*MTcxMjg2NTQyMy4xMi4wLjE3MTI4NjU0MjMuMC4wLjA.&mobile=false&width=1090&height=500&bga=true&needsRedirect=false&jan1offset=-300&jun1offset=-240

Senior PDRA in Physical Oceanography (SAMS, UK)

The job description can be found here: Senior PDRA in Physical Oceanography (D33/23.NF) — Scottish Association for Marine Science, Oban UK

Senior PDRA in Physical Oceanography (SAMS, UK)

The job description can be found here: Senior PDRA in Physical Oceanography (D33/23.NF) — Scottish Association for Marine Science, Oban UK

Postdoc in physical oceanography/climate dynamics, University of Bergen

There is a vacancy for a Postdoc position in climate dynamics at the Geophysical Institute, University of Bergen, Norway, and the Bjerknes Centre for Climate Research. The position is for a fixed-term period of 3 years and is associated with the project “Overturning circulation in the new Arctic (ArMOC)” funded by the Research Council of Norway. The project includes international partners from UK, USA, and Sweden.

The appointed postdoctoral researcher will investigate how present and future Arctic climate change impacts the Arctic overturning circulation. This will be achieved by:

– Quantifying changes in Atlantic Water modification along the Atlantic Water Boundary Current.

– Identifying changes in Atlantic Water pathways in present and future climates using Lagrangian simulations.

– Determining the effects of a changing climate on the Arctic overturning circulation.

More information:

Application deadline is 10 December.

Best regards,

Marius Årthun

2 PhD positions in physical oceanography/climate dynamics at the University of Bergen, Norway

Two Ph.D. positions in physical oceanography/climate dynamics related to the overturning circulation in the Nordic Seas and Arctic Ocean are open at the University of Bergen, Norway. Both positions are for a fixed-term period of 3 years with the possibility of a 4th year with compulsory other work (e.g., teaching duties at the department). The positions are also associated with the Bjerknes Centre for Climate Research.



PhD1 will focus on the conditions conducive for water mass transformation in or near the East Greenland Current, identify when and where these are met, and place the present state of water mass transformation in the East Greenland Current into historical and future contexts. This will be achieved primarily through analysis of available and new observations, including moored and shipboard measurements of velocity and hydrography as well as hydrographic profiles from autonomous gliders and floats.

PhD2 will investigate the mechanisms of overturning variability in the Nordic Seas and Arctic Ocean, and especially the relationship between overturning circulation and surface forcing. The project will also assess how present and future overturning changes in the Nordic Seas are manifested in the subpolar North Atlantic (OSNAP). The PhD project will rely on the analysis of available observations and data from ocean models/reanalyses.

The deadline is 17 October.

Call for Abstract Submissions – North Atlantic Session at OSM24

Jannes Koelling, Jaime Palter, Ric Williams, Fiamma Straneo, Hilary Palevsky

We’re hosting a session at OSM24 on ocean physics and biogeochemistry in the subpolar North Atlantic and would love to get submissions from the OSNAP community. The abstract and session link are below:

PL005 – Physical transport and biogeochemical cycling in the subpolar North Atlantic (

The subpolar North Atlantic is a key region for regulating Earth’s climate which features strong ocean-atmosphere interaction and connects the upper and lower branches of the Atlantic Meridional Overturning Circulation (AMOC). The progressive transformation from warm surface waters into North Atlantic Deep Water (NADW) and their subsequent equatorward spreading drives northward ocean heat transport, sequesters anthropogenic carbon, and oxygenates the deep ocean. Recent advances have significantly improved our understanding of sources of AMOC variability and spreading pathways of NADW, as well as the biogeochemical implications of both.

This session will highlight the latest research on ocean physics and biogeochemistry in the subpolar North Atlantic in a broad interdisciplinary setting. We invite contributions on a diverse set of topics including AMOC variability and its connection to Earth’s climate, the transport pathways and transformation of heat, freshwater, oxygen, nutrients and carbon throughout the basin, and their links to air-sea gas exchange, carbon sequestration, and the biological carbon pump. The session encourages submissions using the wealth of data from past and ongoing observational programs, such as OSNAP, OVIDE, AZOMP, and BGC-Argo, as well as studies using regional or global models.

PhD Position Unravelling the Physics Controlling the Atlantic Meridional Overturning Circulation

Dear colleagues

Within my research group I have an opening for a PhD student to work on the physics of the Atlantic Meridional Overturning Circulation, using realistic and idealized models [project abstract below for more details on the plan]

Applications are welcomed until mid-September.

In the Dutch system, PhDs become paid university employees for a 4-yr period but can also still enjoy the student facilities on campus. They spend their time almost entirely on their research project, except for tasks in assisting with education [max 10-15% of their time, typically grading exams, co-advising BSc and MSc students]. We expect they have a relevant education at MSc level when they start, although if needed they can take MSc courses / attend summer schools.

Feel free to forward the information to potential candidates.


Caroline Katsman


Prof. Dr. C.A. (Caroline) Katsman

Environmental Fluid Mechanics / Hydraulic Engineering

Civil Engineering and Geosciences

Delft University of Technology, NL

The Atlantic Meridional Overturning Circulation (AMOC), characterized by northward surface currents and dense return currents, transports vast amounts of heat to high latitudes, and is largely responsible for Western Europe’s relatively mild climate. Climate models project the AMOC will weaken substantially over the 21st century, which impacts weather, climate, sea level and the oceanic carbon cycle. Ground-breaking new observations have led to a major change in our view on the AMOC, as they revealed that the circulation in the eastern subpolar North Atlantic dominates over that in the west. Notably, climate models tend to simulate the opposite. This illustrates their limited skills in representing key AMOC features and the underlying lack of in-depth understanding of its physical controls. This obviously casts doubt on the reliability of scenarios of future AMOC changes that rely on such models.

From theory and idealized modelling studies it is known that three processes in concert determine the AMOC in density space: (1) densewater formation in the interior of marginal seas and its subsequent export, (2) dense water formation within the boundary current system, and (3) the exchange of waters of differing density with the (sub-)Arctic via overflows. However, their relative importance for shaping the AMOC and feedbacks between them are still unknown. Moreover, both are expected to vary strongly across the subpolar North Atlantic since the key factors regulating their physics (eddy dynamics, surface forcing) vary as well. The observations only register the net effect of these processes, and hence careful analysis of ocean models is imperative to address this knowledge gap.

Here, analyses of realistic and idealized model simulations are combined to exploit the capabilities of both. First, the contributions of the three processes controlling the AMOC are quantified in sub-regions of the subpolar North Atlantic Ocean from a state-of-the-art model simulation, in depth and density space. Next, their sensitivity to oceanic and atmospheric conditions is systematically explored using an idealized model, which facilitates the qualitative identification of cause-and- effect relations and interdependencies. It provides crucial guidance for the final step: the quantitative analysis and interpretation of AMOC variations from the state-of-the-art model simulation. In all, the the project is expected to provide a robust framework to evaluate the skills of models in simulating the AMOC, help establish strategies for improving them, and aid the interpretation of observed AMOC variations.


We are looking for a postdoc in physical oceanography to join the Straneo Lab and the Scripps Polar Center. The postdoctoral researcher will investigate the ocean circulation in the Irminger Sea and along Greenland’s coastal margins, as well as linkages to Greenland’s glacial fjords, as part of the Overturning in the Subpolar North Atlantic Project (OSNAP) and other funded projects. The postdoc is expected to work with a variety of data (moored, vessel-based, and remotely-sensed) and to work closely with Prof. F. Straneo and her team. Engagement in the planning and execution of fieldwork, and in the mentoring of graduate and undergraduate students, is also expected.

The initial term of the appointment will be 24 months, with the possibility of extension. Preferred start date May-June 2023, but this is negotiable.

Job Responsibility:  The individual will be expected to conduct independent, high-quality research in physical oceanography; publish papers; and present work at national and international conferences. The postdoctoral researcher will also work collaboratively with oceanographers at partner institutions both within and outside of the US.

Qualifications: A PhD in physical oceanography or a related field is required by the time of appointment. Experience in collecting and analyzing physical oceanographic data (including programming in Matlab or Python) is highly desirable but not indispensable. Strong oral and written communication skills are expected.

Salary: Commensurate with the individual’s experience and education.

Employment: The University of California, San Diego is an equal opportunity/affirmative action employer with a strong institutional commitment to excellence and diversity (

Application Procedure/To apply: Interested individuals should send a CV, a two page statement of research interest that also summarizes past research, and the names and contact information of 3 references to

Postdoctoral scientist position in ocean physics & biogeochemistry coupling

Full Job Description

We are seeking a postdoc scientist to work on large-scale physical controls on nutrient availability and productivity in the North Atlantic Ocean using satellite observations, models, Biogeochemical-Argo, and model outputs.

Desired Qualifications

  • PhD in biogeochemistry and/or physical oceanography
  • Preference will be given to candidates with training in statistics, and experience with large datasets, including remotely-sensed observations
  • Strong publication record

Job Type

Salary and Duration: Regular, full time with salary commensurate with the individual’s experience. This position is renewable after 1 year contingent on performance, and beyond 2 years contingent on performance and funding.

Location: This project is a collaboration between the Cassar (Duke) and Lozier (Georgia Tech) labs with some flexibility in work location.

Starting Date: As soon as possible.

Interested individuals should send a cover letter, a CV, and the names and contact information of at least 3 references to Nicolas Cassar ( Review of applications will begin immediately and continue until the position is filled.

Work Environment

Cassar Lab: Research conducted in the Cassar lab at Duke University focuses on biogeochemistry and ecophysiology, with the objective of constraining the mechanisms governing carbon, oxygen and nitrogen cycling. The lab is located on Duke’s main campus in Durham, North Carolina.

Lozier Lab: Research conducted in the Lozier Lab at Georgia Tech focuses on the dynamics of large-scale ocean circulation, particularly those of the meridional overturning circulation in the North Atlantic, and on the physical controls of nutrient availability. 

Duke University is an Affirmative Action/Equal Opportunity Employer committed to providing employment opportunity without regard to an individual’s age, color, disability, gender, gender expression, gender identity, genetic information, national origin, race, religion, sex, sexual orientation, or veteran status. Duke aspires to create a community built on collaboration, innovation, creativity, and belonging. Our collective success depends on the robust exchange of ideas-an exchange that is best when the rich diversity of our perspectives, backgrounds, and experiences flourishes. To achieve this exchange, it is essential that all community members feel secure and welcome, that the contributions of all individuals are respected, and that all voices are heard. All members of our community have a responsibility to uphold these values.

Cruise Report AR69-03

By Fiamma Straneo

Cruise Track: AR69-03 Reykjavik to Nuuk, August 18 to September 24, 2022
An awakening of gusty winds and capricious waves
Replace images of Reykjavik
Hesitant movement on the ship as we abruptly begin
Steam, Stop, Sample
Rollercoaster at the surface mirrors the spires of the mid-Atlantic ridge beneath us
As we head across the Irminger Sea
Steam, Stop, Sample
A rhythm slowly unfolds
Steam, Stop, Sample
Waves become longer and movements less hesitant
Sensors pierce through young and old waters on their way down
Warm waters, suggestive of tropical climes 
Give way to cold, newly formed mid-depth waters and 
Look! The deep waters from the Iceland-Scotland Ridge
Crawling at the bottom, invisible to the surface
The essence of the overturning circulation
Text book learning turns into experience
Steam, Stop, Sample
Until the end of the line
Marked by Greenland’s jagged mountains
Here icebergs with mesmerizing shapes drift in cold, clear waters
Every now and then a glacier comes into view

Turn back to pick up buoys left behind last time we were here
Steam, Stop, Release
Hoping they will cede to our call and drop their anchor
Hoping to be the first to spot them as they pierce through the surface 
Waiting turns into excitement. 
Steam, Grapple, Hoist
Help the heroic instruments back onboard 
Scrub them clean of temporary dwellers
Before greedily listening to the stories they tell.
Two years inside the overturning.
Steam, Stop, Release
Steam, Grapple, Hoist
A rhythm slowly unfolds 
As the instruments pile up on deck
Flurry of laptops, cables, instruments
Young scientists turned overnight into crusty, able oceanographers 
Until, one of many low-pressure systems scurrying across the Atlantic,
Stalls Over Us
Roll, Tie-down, Roll
Toes wedged between wall and mattress anchor us during sleep
Water floods across the deck 
Pilot whales surf in the waves by the ship beckoning
Then just as it came the storm leaves
Leaving sunshine, icebergs, glaciers and northern lights 
Steam, Stop, Sample
Deep canyons guide tropical waters towards the ice
Steam, Stop, Sample
Time to head back to the buoys
Steam, Stop, Release
Steam, Grapple, Hoist
Every buoy replaced by a twin
For more stories in two years.

We cross to the Labrador Sea through a steep-walled shortcut
Here it all repeats
Steam, Stop, Sample
Steam, Stop, Release
Steam, Grapple, Hoist
A rhythm slowly unfolds
Backdrop of southwest Greenland’s gentler peaks 
Crane stops working. 
Intermission filled by acrobatic flights of dark-eyed fulmars
Crane fixed. 
Steam, Stop, Sample
Sensors piercing waters cold and warm, fresh and salty
And deep down the dense waters again.
Crawling at the bottom, invisible to the surface
Steam, Stop, Sample
Vials of precious salty waters packed in endless boxes with little numbers
Some emptied into alchemic alembics 
The vials too tell stories.
This time of origin and happenings along the way
Steam, Stop, Release
Steam, Grapple, Hoist
Every buoy replaced by a twin
To measure for two more years
At night different canyons drive same swirling currents

Steam, Stop, Sample
In the day 
Steam, Grapple, Hoist
At night
Crane breaks. No fix this time
Pause nonetheless to watch great shearwaters wing-dipping in cold water
Without a crane weights are dragged on deck 
Until all the twins are deployed.
Take a break in the icy, flat waters of a fjord before heading out into another storm

Cape Desolation beckons us with its submerged rocks and mountains
Whale spouts in the distance and stiff wind ahead
Forty knots gusting fifty
Fifty knots gusting sixty
This is the North Atlantic after all
Roll, Tie-down, Roll
Steam, Stop, Sample
White waves bounce us in the dark.
Until time’s up 
And the lights of Nuuk’s bustling harbor appear
Hesitant movement on land after 37 days at sea
Ocean data, recently declared world heritage, 
Tucked deep in our pockets in a small hard-drive 
A giant effort by a ship, 17 scientists and 22 crew 
A small step forward for overturning science
To be continued to provide answers
twin buoy after twin buoy
vial after vial
one crusty oceanographer after another.