Monthly Seminar Series

Each month we invite NEMO researchers and developers an opportunity to show their work in our seminar series. This takes place on zoom on the first monday of each month. If you are interested in presenting your work, please see the google page . See our calendar on the main page for the next speaker’s abstract and zoom information. This page will provide past speakers of our seminar series.

2026:

May 4th 2026

Patrick Farnole from University of Victoria

“Modeling Ringed and Bearded Seal Future Habitats Indicates Stability, Shifts, and Refugia”

Understanding how marine habitats are changing with a warming Arctic is essential for conservation, management, and adaptation strategies bearing tangible consequences for Arctic communities and ecosystems. Ringed seals and bearded seals rely on specific ice and snow conditions to support critical life history events affecting survival and reproduction. Here, we develop a panarctic habitat suitability model linking life events and environmental conditions. With Earth System Models, we simulate habitat over 1850–2100, revealing a relatively stable past habitat contrasting with rapid regional shifts in contemporary simulations and future projections. Core historical habitats are projected to decline, but two regions arise as potential refugia—the East Siberian Sea and Canadian Arctic Archipelago—that could support ice seal populations towards 2100. These findings underscore the importance of refined monitoring and regional conservation strategies for ringed and bearded seals, and their unique ecosystem

Pouneh Hoshyar from University of Alberta

“High-Resolution Modelling of Labrador Current Eddies and Instability Processes in a 1/60° NEMO Configuration”

The Labrador Sea is a key region of deep water formation that contributes to the Atlantic Meridional Overturning Circulation (AMOC). Along its western boundary, the Labrador Current transports cold, fresh waters originating from Arctic and Greenland. Its close proximity to the deep convection region allows it to potentially influence interior stratification and water mass transformation. However, the role of mesoscale and submesoscale processes, particularly eddies and instability mechanisms, along the western margin of the Labrador Sea in regulating these processes remains incompletely understood and is often poorly represented in coarse-resolution climate models. In this study, we investigate the variability of eddy activity and associated energy conversion processes in the Labrador Current using the high-resolution eddy-resolving configuration of the NEMO ocean-sea-ice model, which includes multiple nests to achieve 1/60° resolution in the Labrador Sea. We quantify the contributions of baroclinic and barotropic instabilities to Eddy Kinetic Energy (EKE). We compute eddy–mean energy conversions, separating baroclinic (mean available potential energy to eddy potential energy) and barotropic (mean kinetic energy to EKE) instabilities, to quantify how shear- and buoyancy-driven processes contribute to transient kinetic energy in the Labrador Current. Our results show that EKE is strongly surface-intensified and organized along the inshore and shelf-break branches of the Labrador Current, with variability largely governed by baroclinic instability. Freshwater exchange across isobaths indicates predominantly onshore transport, while remaining largely confined to the boundary current, suggesting limited lateral spreading into the basin interior. These findings highlight the importance of resolving boundary-current instabilities for accurately representing freshwater redistribution and stratification in the Labrador Sea, with implications for understanding variability in deep convection and the subpolar AMOC.

April 13th 2026

Enrico Pochini from University of Alberta

“Simulating Surface Waves in the Arctic and North Atlantic Oceans. A risk for local Canadian communities”

In the Arctic Ocean, waves are becoming more energetic due to changing conditions in the sea ice and winds: in particular, the decreased sea ice extent in the summer and delayed sea ice formation in the fall, combined with changing winds, allow for stronger waves to reach the coastlines of the Canadian Arctic. These conditions are projected to be even more extreme in the future, as ongoing climate change will exacerbate this trend. Surface gravity waves are already negatively affecting several coastlines in the Arctic by causing coastal erosion. In the Canadian Arctic Archipelago, wave-induced erosion threatens vulnerable coastal infrastructure and dwellings of local communities, thus making it necessary to understand and quantify their impact and evolution, and to devise adaptation plans. We used the spectral wave model Wavewatch III® (Tolman 1997, 2009) to simulate ocean gravity waves formation and propagation for the entire Arctic and North Atlantic Oceans, at 1/4° resolution. The present-day simulation, run over 2002-2022, employs atmospheric reanalysis and existing NEMO ocean simulation output carried out at UofA, and has been positively evaluated against reanalysis and satellite data. The simulated wave height reveals a positive trend in several Arctic Seas and a shift towards more energetic waves in several basins in the Canadian Arctic Archipelago, consistent with the increaìsed impact of storms in the early fall, when sea ice has not yet readvanced. The larger increase in coastal waves is found in the Gulf of Amundsen, Parry Channel, Lancaster Sound, and the Northern Archipelago, although simulated wave heights are not particularly large in such locations. Similarly, in the Hudson Bay, Hudson Strait, and Baffin Bay, which exhibit some of the largest waves, conditions have also been shifting to higher waves. Future work planned involves simulating ocean waves up to 2100, forcing WavewatchIII with projected climate output from CMIP6, potentially with downscaling the atmospheric fields.

Spenser Ross from University of Toronto

“The Influence of Taylor Columns on Ocean Dynamics and Sea Ice in the Chukchi Sea”

The Chukchi Sea contains two distinct shoals, Herald and Hanna. A previous study identified Taylor Columns over these shoals and their role in slowing sea ice retreat. Building on this work, we use passive microwave satellite imagery and, for the first time, a high-resolution ice-ocean coupled model to further investigate the formation and impacts of these Taylor Columns. As a result of their presence, currents are diverted around the shoals. This diversion traps colder stagnant water over the shoals, leading to a delay in ice melt of up to several weeks in the early summer. These ice concentration anomalies are more pronounced over Herald Shoal as a result of its simpler topography compared to Hanna Shoal. As Arctic temperatures rise and the melt season begins earlier, the timing of preferential ice cover over the shoals shifts earlier in the summer, altering ice availability for regional ecosystems.

March 2nd 2026

Jean-François Lemieux

“Impact of non-normal flow rule on linear kinematic features in pan-Arctic ice-ocean simulations”

Linear Kinematic Features are narrow bands of high deformations where sea ice ridges and leads are formed. As these features significantly impact the ocean-atmosphere exchange of heat, moisture and momentum, it is important for sea ice models to represent them properly. The sea ice rheology in continuum based models links the internal stresses with resulting deformations. The commonly used viscous-plastic (VP) rheology is based on an elliptical yield curve and a normal flow rule. This formulation implies that the post-failure deformations are always normal to the yield curve. A drawback of this is that modifications to the yield curve also lead to notable changes to the deformations. I implemented the plastic potential approach of Ringeisen et al. (2021) in the CICE sea ice model. With this formulation, deformations are normal to a plastic potential which is defined independently from the yield curve. This an interesting capability as it allows to independently optimize deformations while parameters defining the yield curve could serve to adjust landfast ice and to a lesser extent sea ice drift. I will give a short course on sea ice rheology and introduce the concepts of flow rule and yield curve. I will discuss the impact of a non-normal flow rule in CICE-NEMO pan-Arctic simulations. Finally, I will show that modifications of the rheology require changes to the redistribution function (ridging) to be consistent.

Noémie Planat

“Pathways of pacific waters in the Canadian Basin of the Arctic Ocean from a Lagrangian perspective.”

Recent declines in Arctic sea-ice extent and thickness are most pronounced in the Beaufort and Chukchi Seas, where thick ice from north of the Canadian Arctic Archipelago usually persists. These changes coincide with significant warming of summer Pacific Waters north of the Bering Strait, extending into the Canada Basin at 60–100 m depth, suggesting a link between Pacific inflow and sea-ice loss. This challenges the view of a strongly stratified Canada Basin, as most models do not resolve the thin summer Pacific Water layer beneath the surface, raising questions about current representations of subsurface heat transport. I will present some work aiming at the characterization of the pathways of summer Pacific Waters into the Canada Basin. These is achieved in a 1/12 regional model with a lagrangian experiment, with 1.5 million of particles advected from Bering Strait to the Canada Basin. The analysis of the trajectories is achieved with a Clustering (machine-learning) algorithm. We highlight seven main pathways and discuss their interannual variability over 26 years of simulation. We further investigate the main processes forcing these pathways from basin scale to mesoscale processes.

February 2nd 2026

Youyou Lu from DFO

“Sea level variations and underlying dynamics: Based on comparison and analyses of observation data and models”

The presentation is based on recently published and ongoing work on analyses of monthly sea levels during 1993-2023. Results from ¼-deg and 1/12-deg NEMO simulations covering Canada’s Three Oceans, without data assimilation, are compared with tide gauge and altimeter observations, and data assimilative global ocean reanalysis products at 1/12-deg (GLORYS12v1) and ¼-deg (ORAS5) resolutions.

For the Northwest Atlantic (off the coast of Canada and northern USA), only GLORYS12v1 possesses skills for sea level anomalies at time scales longer than 20 months. This suggests the influence of strong nonlinear dynamics, and innovative methods (e.g., ensemble prediction and/or Machine Learning) may be needed to make reliable predictions for future changes beyond synoptic time scales. Ongoing work extends to understanding and comparing the mechanisms of sea level variations between the western and eastern boundaries of the North Atlantic and North Pacific.

Adam Fu from the University of Alberta

“Hotspots of small mesoscale eddies in the western Arctic Ocean observed by SWOT”

Ocean eddies play crucial roles in climate and marine ecosystems. Still, small mesoscale eddies in the climate-sensitive and biologically unique Arctic Ocean, remain poorly characterized and understood due to the coarse resolution of traditional gridded altimetry products and sparse in-situ observations. Here, we show that the Surface Water and Ocean Topography (SWOT) satellite mission overcomes these limitations through unprecedented two-dimensional high-resolution measurements of sea level anomalies. We demonstrate SWOT’s capability to quantify previously unresolved eddy properties, revealing three persistent hotspots of mesoscale eddies in the southern Beaufort Sea that actively transport low-salinity, heat-retaining, and nutrient-enriched waters from the continental shelf to the interior basin. The observed eddies demonstrate their critical role in shelf-basin exchange while revealing biases in current high-resolution models. These findings advance our understanding of Arctic mesoscale processes and provide essential benchmarks for improving ocean models for this rapidly changing environment.

2025:

December 1st 2025

Rowan Brown from LMU Munich

The Effects of Tides and Submesoscale Mixed Layer Eddies on Deep Convection in the Labrador Sea: Simulations at Resolutions Consistent with Coupled Climate Models -

Wintertime deep convection in the Labrador Sea regularly deepens the mixed layer below 1,000–2,000 m. Within eddy-present ocean general circulation models, limitations imposed by the grid resolution commonly result in deep biases beyond these observed extrema. In this study, we have evaluated whether these deep biases can be reduced by using (1) the Mixed Layer Eddy parameterisation, introduced by Fox-Kemper et al. (2011), and/or (2) tidal forcing. Using a suite of 1/4-degree resolution coupled ocean-sea ice NEMO simulations (ANHA4), we found that the mean impact of both the parameterisation and tidal forcing was to inhibit deep convection and shoal the Labrador Sea’s wintertime mixed layer. In this talk we will show how these results hold for two independent experiments using two different atmospheric forcing products (CGRF and ERA-Interim) and discuss the likely dynamical drivers involved.

Andrew Hamilton from the University of Alberta

The MObservationalist Approach: thoughts from a model-adjacent ocean observationalist -

Advancing our understanding of ocean dynamics and the role of marine heat and freshwater transport, biogeochemical cycling, and climate feedbacks is critical to assess the current state of the ocean and predict its future evolution. To progress in this field requires the use of a variety of tools, including the complimentary application of in situ observations and numerical ocean circulation model. As a field-going Arctic oceanographer I have utilized a wide variety of observational techniques, from CTD profiling through sea ice with Inuit partners, to deploying autonomous underwater vehicles from large icebreakers, to multibeam seabed mapping from polar sailboats. In situ measurements are essential for understanding the real world, but observational datasets are limited in time and space. In contrast, numerical ocean circulation models are an extraordinarily powerful tool that can, in essence, allow an oceanographer to be everywhere all at once. Models are simulations however, and their ability to represent reality is only as good as their boundary and initial conditions, the forcings used to drive them, and the physical parameterizations within. Here, I will discuss what I have learned working alongside a NEMO ocean modelling group, some the limitations and strengths of models, and how field observations and models together have great potential to advance the state of oceanography in a rapidly changing world.

November 3rd 2025

Jonathan Izett

“How large does a “regional” domain have to be to accurately simulate Canada’s three oceans on climate timescales?”

The Canadian Centre for Climate Modelling and Analysis (CCCma), in collaboration with Fisheries and Oceans Canada (DFO) and researchers at the University of Alberta (UofA), is developing a Canadian Three Oceans Downscaling System (CanTODS). The development of this model configuration will provide consistent, higher-resolution physical and biogeochemical climate projections for the northeastern Pacific, Arctic, and northwestern Atlantic oceans. Initially developed at ¼-degree resolution, CanTODS will be deployed at 1/12-degree resolution on a modified eORCA grid.

Antoine Haddon

“Implementing sea ice biogeochemistry in the Canadian Earth System Model”

In the Arctic, blooms of primary producers develop at the bottom of sea ice, leading to high concentrations of biomass accumulating at the ice-ocean interface. These dense ice algal formations detach when sea ice warms and can sink rapidly, thereby contributing to the deep export of carbon, as confirmed by the observation of undegraded ice algal strands and aggregates on the seafloor. Ice algae also play a special role in the Arctic ecosystem as their blooms are the first pulse of primary production when light returns to high latitudes and are often the only food source for primary consumers in the spring. The Canadian Sea Ice Biogeochemistry model (CSIB) is being implemented in the Canadian Earth System Model (CanESM) within the NEMO ocean model, thereby allowing the inclusion of sea ice biogeochemistry in both regional and global climate simulations. The sea ice model (SI3) of NEMO offers a number of advantages towards implementing sea ice biogeochemistry, as in particular SI3 includes a sub-grid cell distribution of sea ice thickness, leading to a better representation of the heterogeneity of light at the bottom of sea ice. Along with improvements in the modeling of photophysiology and export processes, this new implementation of CSIB therefore allows a more accurate representation of ice algal blooms. Recent developments to CSIB included adding variable ice algal stoichiometry to represent photoacclimation and the seasonal evolution of carbon to chlorophyll ratios. Sea ice-ocean exchange processes were also further refined, including turbulent diffusion of nutrients as well as the various mechanisms by which ice algae are released from sea ice into the water column.

October 6th 2025

Abdoul Tall

“Advancing Biogeochemical Parameterizations in SalishSeaCast: Improved Representation of Oxygen Dynamics in the Salish Sea”

The SalishSeaCast model, a coupled physical-biogeochemical configuration of the hydrodynamic model NEMO-3.6, is used to reproduce the dynamics of the Salish Sea. We present recent advances in the SalishSeaCast model with a focus on oxygen. Key updates include explicit riverine inputs of dissolved and particulate organic nitrogen (DON and PON); stepwise remineralization (PON → DON → ammonium) with linear light-inhibited nitrification; inclusion of diatom resuspension at the seafloor; and a revised zooplankton closure (Z₂) , with explicit mortality and excretion pathways. Dissolved oxygen pathways are also refined through updated sinking and bottom reflection schemes that capture sediment oxygen demand. Interannual simulations from 2010–2020 resolve both the seasonal cycle and episodic renewal-driven oxygen inputs, linking physical exchange with biogeochemical demand. The new parameterization improves the realism of bottom dissolved oxygen and resolves previous biases. In Saanich Inlet, the previous configuration produced unrealistically high deep oxygen, whereas the new version, with a deepened Satellite Channel and increased bottom friction, captures the expected low-oxygen conditions. In Puget Sound, oxygen dynamics are shaped by a combination of stratification, remineralization, and climate forcing, with Lynch Cove standing out as the most sensitive sub-basin. These refinements improve the realism of the timing of oxygen consumption, resolving previous underestimations of bottom dissolved oxygen drawdown and better representing the balance between physical flushing and biogeochemical demand.

Mukulika Pahari, Paul G. Myers

“Mechanisms behind the Bifurcation of Irminger Water into Davis Strait and the Northern Labrador Sea”

Irminger Water (IW), originating in the Irminger Current, is an important water mass supplying heat and salinity to the western subpolar North Atlantic. As the warmest (4-6°C) and most saline (34.9 PSU) water mass entering the region at intermediate depths, it plays varied roles in stratification and sea ice and glacier melt. IW brings heat to the interior of the Labrador Sea and helps maintain its weak stratification, essential for deep convection. IW also reaches the marine-terminating glaciers at Greenland through fjords where heat from this water mass melts the glaciers at depth and destabilizes them. This study investigates the variability and mechanisms of the flow of IW in the western subpolar North Atlantic and specifically the bifurcation near Fylla Bank that allows this water mass to enter Baffin Bay or the northern/western parts of the Labrador Sea. We use a 1/60° horizontal resolution simulation (LAB60) run with the NEMO (Nucleus for European Modelling of the Ocean) model and Lagrangian particle tracking with OceanParcels to estimate the pathways of IW and to find the drivers of this flow. The results from this study allow us to improve our understanding of ocean heat forcing to the subpolar gyre.

September 8th 2025

Bill Merryfield

“Application of ECCC’s NEMO-based global climate models to seasonal and decadal prediction”

A major application of CCCma’s global Earth system models, in addition to climate projection under future scenarios, is predicting climate variations and change over the coming season to decade. Since mid-2024, ECCC’s operational seasonal forecasts have come from CanESM5, the first of CCCma’s global models to employ NEMO as its ocean component, together with a Meteorological Research Division model that couples the GEM5.2 weather prediction model to NEMO. CanESM5 also produces ECCC’s decadal forecasts which are updated annually. This talk will describe the models and initialization methods employed by ECCC’s seasonal and decadal prediction systems with an emphasis on their NEMO components, together with associated products including forecasts of sea surface temperature and Arctic sea ice. Current efforts toward developing additional ocean-relevant forecast products and downscaling using the Canadian Three Ocean Downscaling System (CanTODS) are briefly surveyed.

Luiz Henrique da Silva

“ANHALYZE: Handling and Visualizing NEMO outputs”

ANHALYZE is an open-source package, actively being developed in Python, aiming to simplify the analysis of outputs from the Arctic and North Hemisphere Atlantic (ANHA) configuration of the NEMO ocean model. This toolbox is designed to enhance oceanographic research by providing an accessible framework for users with different levels of experience. The main goal of the first release is to support users who are not familiar with ANHA outputs and/or Python programming, while also offering a starting point for more advanced analyses. The first version of ANHALYZE handles netCDF files in the ANHA-specific format and has key functionalities such as region selection with automatic awareness of units and dimensions, and the ability of easy map generation. Users can create maps with customizable projections, property-specific color schemes, and on-the-fly masking. Additionally, comprehensive documentation and tutorials are provided to guide users through the available features. Looking ahead, future versions will introduce additional scientific functions (e.g. heat and freshwater content calculators), and incorporate advanced tools, such as an interactive mask generator. ANHALYZE follows open-source principles and is hosted on GitHub, promoting collaboration and further development by the scientific community.

June 2 2025:

Xiner Wu

“Arctic gateways: exploring the impacts of the Bering Strait in subpolar North Atlantic during the Middle Holocene”

During the Holocene (the last 11,700 years), tremendous changes happened worldwide. For example, the Bering Strait being only ~53 m deep, would have been closed during glacial intervals with a global sea level decrease, and then reopened during interglacial intervals (e.g., Elias et al., 1996). Sedimentary records (e.g., Jakobsson et al., 2017; Yamamoto et al., 2017) suggest that the Bering Strait inflow to the Arctic was weak in the Early Holocene (11.7-8 thousand years ago) and stronger during the Middle Holocene (8-3.5 thousand years ago). The opening and the subsequent deepening of the Bering Strait from the Early to the Middle Holocene could have increased freshwater influx and outflux of the Arctic Ocean, possibly causing a weakening of the AMOC. This study aims to investigate the sensitivity of North Atlantic dynamics to varying Bering Strait inflows during the Middle Holocene using NEMO 3.6 and the ANHA4 configuration. Simulations are currently underway, and forthcoming analyses will evaluate the resulting oceanographic changes and assess their consistency with proxy data.

Yarisbel Garcia Quintana

“On the formation mechanisms of Nares Strait ice arches in the NEMO model”

Nares Strait, between Greenland and Ellesmere Island, is one of the main pathways connecting the Arctic Ocean to the North Atlantic, and a major conduit along which multi-year sea-ice leaves the Arctic. This transport is modulated by the winter-time formation of ice arches at both ends of the strait. The arches are tightly linked to the maintenance of the North Water Polynya. Therefore, the strait plays an important role in the mass balance of the Arctic sea-ice, influencing the climate of the North Atlantic region. However, the remoteness of Nares Strait and the harsh atmospheric and oceanic conditions that predominate nearly all year round, makes it difficult for data collection. While the satellite imagery might offer a very high spatial resolution, their usage is considerably limited as they fail in providing information on sub-surface ocean dynamics properties. As such, many studies have used numerical models to investigate the mechanisms behind Nares Strait ice arches formation. Initial studies suggested that the formation and the stability of the arches depend on the parameterization of the elastic–viscous–plastic rheology. However, more recent research has suggested that, even when using an EVP approach, a specific set of parameters may need to be modified to better simulate Arctic sea-ice on a basin-scale. Our study presents a suit of experiments carried using the state-of-the-art ocean model Nucleus for European Modelling of the Ocean, coupled to two different sea-ice models LIM3 and SI3. Through these experiments we explore Nares Strait sea-ice sensitivity to atmospheric forcing, model resolution, tides and to a set of parameters involved in ice dynamics and mechanical redistribution. Our main goal is to identify the ideal numerical setting to realistically simulate Nares Strait arches formation, and therefore, the mechanisms behind it. The preliminary results of this project will be presented during the Congress.

May 5 2025

Stephanne Taylor

“Transitioning Port Models to NEMO4.2 with Wetting and Drying”

Fisheries and Oceans Canada currently has a series of six high-resolution (dx ~500m-20m) port ocean prediction systems developed using NEMO3.6 running in a best-effort operational context. Work is underway to migrate the port-scale prediction systems to NEMO4.2, taking advantage of new features including wetting and drying. Wetting and drying is important for models with high tidal ranges or shallow bathymetry, including the Bay of Fundy and the south Salish Sea. We present ongoing work and some preliminary results.

Madhurima Chakraborty, Juliana M. Marson, Paul Myers

“Exploring the environmental factors controlling the iceberg season severity along the east coast of Canada”

As the Arctic warms, discharge from the Greenland ice sheet in the form of icebergs has increased in the last decades. Some of these icebergs drift to Canada’s east coast where they become significant hazards to ships and other offshore structures. The yearly number of icebergs crossing 48°N is widely accepted as a measure of iceberg severity on the east Canadian coast. This number has fluctuated widely from year to year in recent decades, making the iceberg season unpredictable, and causing concern for marine industries. Former studies have attributed this variability to different environmental factors, such as ice conditions encountered by iceberg enroute, calving rates from Greenland glaciers, and the ocean temperature over the Labrador shelf. However, scientists do not agree upon which of these factors plays the key role in determining the severity of the iceberg season. Moreover, scarcity of information about icebergs’ behavior outside of the region monitored by International Ice Patrol in collaboration with Canadian Ice Service, makes the understanding of what governs the icebergs’ drift in the upstream portions of their trajectories challenging. To gain deeper insight into this matter, we analyzed observations and outputs from Nucleus for European Modelling of the Ocean (NEMO version 3.6), an ocean model that treats icebergs as Lagrangian particles and is coupled with a sea ice model. Iceberg count south of 48°N showed stronger correlations with Labrador shelf temperature and sea ice area than with Greenland calving rates. Moreover, model outputs suggest that another important driver affecting the number of icebergs reaching 48°N has not yet been considered in the literature: variations in the ocean circulation in Baffin Bay. Most likely, the main factor driving the iceberg season severity off Canada’s east coast changes in different periods, depending on the environment’s mean state.

April 7 2025

Luiz Henrique da Silva

“Baffin Bay Annual Freshwater Content and Budget”

Baffin Bay significantly contributes to transporting and transforming freshwater from the Arctic Ocean to the North Atlantic Ocean. Nevertheless, our understanding remains incomplete regarding the mechanisms involved in storing and dispersing of the this freshwater within the bay before it leaves through Davis Strait. In order to investigate the freshwater content (FWC) seasonal variability in Baffin Bay, we used NEMO 3.6 model coupled with The Louvain-La-Neuve sea ice model (LIM2) - 1/4º horizontal spatial resolution. We have analyzed the FWC annual budget within Baffin Bay and determined that there is a surplus of freshwater into the bay from May to September, while there is a FWC decrease in the remaining months. After considering all sources and sinks, the annual FWC cycle seems primarily influenced by sea ice growth and melt. We have also applied the Empirical Orthogonal Function (EOF) analysis to examine the FWC variability in Baffin Bay. THe first EOF represents 82.8% of the FWC’s total variance and likely results from the melting of sea ice in central Baffin Bay and land runoff near coastal areas. Along the Baffin Island Current pathway, this mode appears to be predominantly driven by freshwater transport out of the bay associated with the current. The second mode, which accounts for 12.1% of the FWC’s total variance, exhibits a heterogeneous spatial pattern, suggesting that various local physical forces such wind-ice stress and inflow of Atlantic Water have influence on it.

Ruijian Gou

“The changed nature of the Arctic Ocean in high-resolution climate models”

High-resolution climate models can resolve more climate variability, including ocean eddies and climate extremes, which are projected to be more prominent with sea ice retreat. They are therefore important for studying the interactions of climate variability at different scales in the Arctic Ocean.Although the meridional overturning circulation in high-resolution climate model shows a smooth weakening on a basin scale, there are abrupt shifts on regional scales only in the high-resolution model, such as a strengthening towards the Arctic. This is induced by resolved ocean eddies and boundary currents that increase the heterogeneity of density at ocean boundary, highlighting the disproportionate and interconnected cross-scale climate tipping points in high-resolution models.The Arctic marine heatwaves, as resolved in high-resolution climate models, would induce stronger future Arctic Ocean warming than current projections, as a feedback from the extreme events to the climate. We also identify an abrupt shift in the Arctic Ocean warming due to shifted Arctic sea ice and increased marine heatwaves in recent years, highlight the importance of increasing extremes in inducing climate transitions.

March 3rd 2025

Natasha Ridendour

“Projecting future climate changes for the Salish Sea using high resolution downscaling”

The Salish Sea, a marginal sea located and shared between British Columbia and Washington State, supports an active and diverse ecosystem in addition to the economic and recreational activities of nearly 9 million locals who live along its shores. Given the Salish Sea’s importance, future climate projections can provide useful information for how to manage the resources and services it provides in the years to come. Using the SalishSeaCast ocean model configuration, based on Nucleus for European Modelling of the Ocean (NEMO), a historical period (1986-2005) is used to evaluate changes in the Salish Sea for the years 2046-2065 using the Canadian Earth System Model (CanESM2) under two future climate scenarios: Representative Concentration Pathway (RCP) 4.5 (moderate mitigation) and RCP 8.5 (no mitigation). We find that the waters in the Salish Sea are becoming less dense, due to higher temperatures and a shift to lower salinities. In addition to the physical model, SalishSeaCast is run with biogeochemistry, with our focus being on three ecosystem stressors: temperature, oxygen, and ocean acidity. We identify regions in the Salish Sea that are more vulnerable to extreme conditions in the future using two different baselines.

Inge Deschepper

“A comparison of two biogeochemical models, BLINGv0 and BiGCIIM, and their effectiveness in predicting productivity in a sub-Arctic region, the Hudson Bay Complex”

As part of the BaySys project, an analysis and comparison of two simplified biogeochemical models, BLINGv0 and BiGCIIM, was done to assess their predictive capabilities of chlorophyll a in the Hudson Bay Complex (HBC). The two biogeochemical models were coupled with the NEMOv3.6 ocean circulation model and the LIM2 sea-ice model, with BLINGv0 representing only phosphate and iron-limited planktonic processes, while BiGCIIM includes nitrogen-limited planktonic and sea-ice biogeochemistry. The models were evaluated against observational and satellite data from 2003 to 2021, focusing on chlorophyll a concentrations as a proxy for productivity. BLINGv0 showed a better spatial representation of chlorophyll a concentrations, possibly due to its iron limitation constraint, while BiGCIIM performed better in localised areas, likely due to its explicit phytoplankton-type representation and light usage under ice. While both models share fundamental principles of nutrient and light limitation for growth, their responses to physical forcings and potential key drivers of variability differ due to their base currency and implementation of it. This highlights that both simplified biogeochemical models were sufficient to resolve spatial and temporal patterns no matter their currency, but investigation into region specific dynamics would need base currencies to be considered.

February 3rd 2025

Claire Parrott

“The Role of Glacier Melt on Freshwater Dynamics in the Canadian Arctic”

Marine-terminating glaciers, numerous in the Canadian Arctic Archipelago (CAA), are an important and dynamic source of freshwater to the Arctic freshwater system, with glacial inputs modifying local ocean properties and contributing to regional freshwater budgets. Despite their abundance, knowledge is lacking on glacier-ocean systems across the CAA, and these systems are often omitted in regional studies of freshwater transport or storage. In this study, we examine the nature and spatial extent of glacial meltwater influence on freshwater dynamics in Jones Sound, a glacier-rich region in the CAA, to better understand the contributions and of glacier meltwater to the regional oceanic freshwater system, the interannual variability of freshwater within Jones Sound, as well as the transport and export of freshwater from the region. We employ a high-resolution a coupled ocean and sea ice model of the Arctic and Northern Hemisphere Atlantic at 1/4 degree resolution to examine a regional freshwater storage and the freshwater budget of Jones Sound. Results show an accumulation of freshwater over the study period and changes in the freshwater budget: notably a decrease in magnitude of both the dominant source and sink of freshwater to the region. These changes to the local freshwater budget show glacier melt plays an increasingly prominent role in freshwater dynamics in Jones Sound.

F.Dupont and collaborators

“Efforts towards NEMO4 and development plans for a contribution to the NEMO consortium”

The Canadian Operational Network of Coupled Environmental Prediction Systems (CONCEPTS) has developed a suite of ocean prediction systems from global to coastal scales. They are all based on NEMO v3.6 coupled to CICE v4.0. This year, the system sea ice component was updated to CICE v6.2.0 and we are in the process of testing the v4.2.2 NEMO component. CICE6 finally offers dynamic array allocation and new physics such as mushy layer, and NEMO4 is expected to improve on the run time, new bulk formulae, turbulence below sea ice and offers new features such as wetting and drying. This presentation will show early results using NEMO4 and CICE6 at different scales and some of the challenges. We are also developing a plan for contributing to the NEMO consortium that I would like to share with you during this presentation and get feedbacks.

January 6th 2025

Paul Myers

“Modelling of the Arctic Ocean and Labrador Sea at 1/60th Degree”

Our group has carried out simulations of the Labrador Sea at 1/60th and shown that very-high resolution significantly improves the model solution. That resolution, by representing the mesoscale and part of the sub-mesoscale significantly improves the simulation of boundary current system, eddies and shelf-basin exchange, with the small-scale processes combining to also improve the large-scale circulation and overturning. Given such improvements for the Labrador Sea, we now examine modelling the entire Arctic Ocean and the subpolar North Atlantic Ocean north of 53N latitude. The configuration is named ARC60. The experiment also includes an iceberg module and tidal forcing. Here we present some of our ongoing analysis using the two very high resolution configurations. We explore questions related to water formation in the Labrador Sea and Greenland melt, behavior of the Labrador Current and the Deep Western Boundary Current. We also explore the impact of Greenland runoff on driving coastal seasonal features in Melville Bay. Finally we look at eddies and small scale processes in the Arctic Ocean and Beaufort Gyre.