STUDENTS & POSTDOCS

Laura Castro de la Guardia – Graduate Studentcastrodelaguardia_l
University of Alberta
OSNAP Advisor: Paul Myers

My background is ecosystem biology, and withing Dr. Myers’s physical oceanographic modelling group I study primary productivity in the Labrador Sea, as well as the evolution of oxygen and carbon concentration in the Labrador Sea Water using a state of the art ocean sea-ice model (NEMO) coupled to a biogeochemical model (BLING). The simulation runs from 1958 to 2013.

Elizabeth Comer – Graduate Student
National Oceanography Centre and University of Southampton
OSNAP Advisor: Penny Holliday

We will be examining the internannual variability of volume, heat and freshwater transport as observed by the Extended Ellett Line since 1996, decomposing the net transport into various components of the overturning circulation. We will examine the changes in the light of present understanding about the response of the subpolar gyre to local and remote mechanical and buoyancy forcing. We will critically examine whether the results support those hypotheses and identify other mechanisms at work. We will use data from across the subpolar gyre and high resolution models to test our hypotheses.

Nick Foukal – Graduate StudentOSNAP-5
Duke University
OSNAP Advisor: Susan Lozier

 I’m researching the upper limb of the overturning circulation and its effects on the oceanic heat transport. Specifically, I’m trying to understand how, and on what time scales temperature anomalies travel from the subtropical Gulf Stream to the eastern subpolar gyre off northern Europe. I was on the August OSNAP cruise, deploying the mooring arrays off the east and west coasts of Greenland.

Yarisbel Garcia Quintana – Graduate Student
University of Alberta
OSNAP Advisor: Paul G. Myers

By using an ocean-sea ice coupled numerical model (NEMO), my research has been focused on Labrador Sea Water (LSW) formation rate variability as well as AMOC strength under different scenarios, by implementing sensitivity experiments. I have been working with Paul G. Myers as my Supervisor. Part of my research also aims to look at the variability and formation rates of the Denmark Strait Overflow Water (DSOW) and Iceland-Scotland Overflow Water (ISOW). LSW, DSOW and ISOW contributions to the AMOC strength and variability in the sub-polar gyre is also one of my questions.

Patricia Handmann – Graduate Studentp1030904
GEOMAR
OSNAP Advisor: Martin Visbeck

My PhD project aims to understand deep transport variabilities from Model and Observational data. It focuses on the mechanisms causing variabilities on different timescales in the deep limb of the overturning circulation. What are the connections of changes in regional wind stress curl, hydrographic and dynamic properties in NADW and its single components LSW, NEADW and ISOW? Also the evolution of deep water masses traveling from their source region in the north down south is a field of interest. I am trying to answer these questions via model analysis of the high resolution model VIKING20 and the analysis of observational data from different locations in the North Atlantic.

Loïc Houpert – PostdocDSC_2029_2
Scottish Association for Marine Sciences, Oban
OSNAP Advisor: Stuart Cunningham & Mark Inall

The purpose of my job is to support the physical oceanographic observations being made as part of UK-OSNAP and to undertake scientific research with those observations in collaboration with national and international partners. Particularly I am involved in the planning and execution of the UK mooring and glider programme.

Moorings and gliders will be used to measure volume, heat and salt flux in the eastern gyre.

Xianmin Hu – Postdocxianmin_hu
University of Alberta
OSNAP Advisor: Paul Myers

I am working with numerical modelling (the VITALS project), focusing the arctic and subarctic freshwater processes, e.g., sea ice, runoff and Greenland meltwater, and their impacts on the oceanic physics. It’s very interesting (also important) to see how/how much the upstream freshwater flow down to south, their role in Labrador Sea deep convection and large-scale Atlantic Meridional Overturning Circulation.

Liping Ma – PhD Student
University of Liverpoolliping-ma1
OSNAP Supervisor: Ric Williams

My PhD project will examine how different atmospheric regimes affect the ocean heat storage and overturning in the North Atlantic Ocean and the wider climate system.

The prevailing view is that much of the ocean variability in heat storage in the North Atlantic is understood in terms of slowly varying climate modes, i.e. fixed pressure patterns such as the North Atlantic Oscillation. Instead we wish to explore how the ocean heat uptake and overturning is controlled by the position and frequency of individual weather systems, in particular atmospheric blocks, which determine the path of the jet stream.

Neill Mackay – Postdoc
National Oceanography Centre
OSNAP Advisor: Chris Wilson

Along with my supervisor Chris Wilson, I am developing a novel inverse method which will be applied in the North Atlantic to complement the OSNAP observations. The method is based on recent work in thermohaline coordinates, and uses a balance which exists between advective, diffusive and surface fluxes to gain information about the circulation. By combining observations of temperature and salinity at the open boundary of an enclosed volume (for example the Arctic ocean enclosed by a constant latitude section at 60N) with surface fluxes into the volume, the inverse method can determine the velocities through the interface and diffusive fluxes in the interior.

We are currently working on validating the inverse model using data from the 1 degree version of the NEMO forward ocean model. Once we have completed work refining the inverse method, we plan to apply it to climatological observations and diagnose the circulation and mixing for the OSNAP region. We will compare, and perhaps later combine our results with observations from the OSNAP moorings with the aim of enhancing our understanding of the circulation of the subpolar gyre.

Juliana M. Marson- Postdoc
University of Alberta
OSNAP Advisor: Paul G. Myers

I am a physical oceanographer who worked with Antarctic research in the past. As I wanted to gain more experience with Arctic research and numerical modelling, I came to Canada to work with Dr. Myers group. Currently, I am implementing an interactive iceberg module in our model and analyzing the importance of iceberg meltwater to the North Atlantic Ocean.

Ryan Peabody – Graduate Studentp1050013p1050013 Duke University
OSNAP Advisor: Susan Lozier

The AMOC has long been appreciated as a pathway for heat and salt transport from the subtropical to subpolar gyre. Less appreciated is the role of the AMOC as a pathway for nutrient transport. My work focuses on determining the fate of tropical nutrients carried northward by the Gulf Stream, and how that throughput might impact primary productivity in the subtropical and subpolar gyres. I work primarily with historical datasets and remote sensing data, and am looking forward to incorporating the measurements of the AMOC made directly by the OSNAP array into my work. 

https://sites.duke.edu/ryanpeabody/

Petit Tillys – Graduate Student
IFREMER/LOPS
OSNAP Advisors: Virginie Thierry & Herlé Mercier

As part of my PhD, I’m studying the circulation around and over the Reykajnes Ridge (South of Island). The circulation will be quantified owing to an inverse model (and in-situ data measurements acquired along 4 sections in June 2015). As part of the RREX project, this study aims to identify the processes controlling the dynamical connections between the two sides of the ridge, which are characterized by a strong asymmetry of the properties, and the role of the major fractures zones in the circulation. The better understanding of current-topography interaction will help provide recommendations for the improvement of climate models, which tends to bring too much warm and salty water in the Irminger Sea.

Virginie Racapé – Postdoc
IFREMER/LOPS
OSNAP Advisors: Virginie Thierry & Herlé Mercier

My job focuses on the deep-limb of the overturning circulation and the connection between subpolar and subtropical gyre. In this context, I am using Deep-Argo-O2 launched in the Subpolar gyre since 2015 to better document the deep circulation and its water masses as well as ventilation mechanism. This study will be completed by cruises data and Argo-O2 data available in the North Atlantic to better understand alternation between cold and warm periods observed since 1990s and their impact on the basin scale.

Sijia Zou – Graduate StudentQQ图片20141002091930
Duke University
OSNAP Advisor: Susan Lozier

 My work focuses on the deep limb of the overturning circulation, specifically on the connection between convection in the Labrador Sea and the export of Labrador Sea Water (LSW) to the subtropical gyre. I seek to understand if the variability of LSW export is driven by the change in convection of the source region, and if not, what the dominant mechanism is that controls the export variability.  I use ocean models to track the paths of water particles in a Lagrangian frame and compute the exported variability. To validate our model results, I will also analyze results from hydrographic data and RAFOS floats deployed as part of the OSNAP project.