Our keynote speakers
Our plenary speakers
Our keynote speakers
Our plenary speakers
All Nansen Legacy researchers still actively involved in the project should purchase their travel as they have done previously (follow guidelines at their own institution) and apply for travel reimbursements by their respective partner institutions. The institutions will then send a compiled claim to the project office.
For symposium registration, the project administration will soon send you a booking code by email that will allow you to register for the symposium and book the hotel room through the registration system. Accommodation costs and the participant fee will directly be covered by the Nansen Legacy.
Marianne Kroglund (Norwegian Environment Agency, Norway)
Environmental problems are very often tricky problems: they are persistent, many are vast in scale with no clear end, and involve political decisions and struggles that are more about values, world views and ideology than they are about scientific facts. Even if it may seem crystal clear what environmental problems we are facing, the ecological and biological elements on the effect side of these problems are dynamic and complex, and the social and political elements on the solution side are constantly changing. And not the least; looking into the future, the complexity and uncertainty grows even larger. In a rapidly changing world, and in lack of linear patterns from science to action; what does it take to make decisions? Do we have the knowledge and knowledge systems we need to inform complex challenges? In this talk, rather than looking at the barriers I will focus on what I think are enabling factors for efficient uptake of science and knowledge in management and decision-making processes related to climate, nature and pollution.
Marius Årthun (University of Bergen, Norway)
The Arctic sea-ice cover is currently retreating and will continue its retreat in a warming world. However, the loss of sea ice is neither regionally nor seasonally uniform. Sea ice conditions and associated drivers of variability differ substantially from region to region within the Arctic, and considering only pan-Arctic trends thus masks competing regional trends and makes the underlying drivers and implications difficult to ascertain. Arctic sea-ice loss is also not seasonally uniform. Whereas the overall pan-Arctic sea-ice loss has been largest in summer, the winter trends are of the same magnitude in the southernmost regions, and particularly in the Barents Sea.
In this talk, I will detail the seasonal and regional transition to an ice-free Arctic based on observations, large ensemble simulations, and CMIP6 models. The key drivers of present and future sea-ice variability and the relative contribution of internal (natural) and external forcing will be discussed.
Benjamin Planque (Institute of Marine Research, Norway)
Conventional fisheries management relies on models that estimate how fish populations have changed in the past and how they might change in the future. The transition to ecosystem-based management has shifted towards considering multiple factors such as how different species interact, and how climate change and multiple human activities (e.g., fishing, shipping, tourism, energy) affect ecosystems and the services they provide. To support this approach, new models are needed that can consider all these dimensions together (rather than just considering one or few species at a time). While ecosystem models have been around for a while, they are not yet widely used in management. In this presentation, I will discuss existing ecosystem models and how they are, or can be, used in ecosystem-based management. I will also talk about some of the challenges that need to be addressed to make these models more useful. Finally, I will suggest how models can be developed to better support management in the future.
Oliver Müller (University of Bergen, Norway)
With its large interannual differences in ice extent, the Barents Sea is the ideal large-scale simulator to investigate how the Arctic marine ecosystem will respond to reduced sea-ice cover. By connecting seasonal studies in the Barents Sea (Nansen Legacy) with a year-long drift through the central Arctic Ocean (MOSAiC) we will reveal new insights on important microbial processes in the Arctic, how they differ from our expectations and set them into historical context (Nansen`s Fram expedition). We have focused on measurements of microbial abundance, including virus, bacteria and small phytoplankton and activity measured as bacterial production and our results clearly demonstrate the importance of sea ice in structuring microbial communities as response on phenological variability in primary production. To better understand the consequences of an ice-free future for Arctic microbial communities, we need to improve our knowledge on how sea ice is affecting microbial processes and whether our current paradigms on seasonal processes are more complex than previous thought. We need to compare our present observations with the past, e.g. by use of ancient DNA, to disentangle whether the new knowledge is a result of improved measurements or of a changed Arctic.
Malte Müller (Norwegian Meteorological Institute, Norway)
The development of coupled Earth modeling systems on a kilometer-scale resolution is a new frontier for operational forecasting. However, accurately representing interactions between the atmosphere, snow/sea-ice, ocean, and waves is challenging due to the complexity of interactive mechanisms, the limited accuracy of the model components, and the availability of observations to resolve and assess relevant coupled processes. An overview of recent work will be given to assess the sensitivities of the model system to the representation of the sea-ice and snow by utilizing a multitude of observations, including field-campaign data, as well as satellite retrievals and standard in situ observations.
Camille Li (University of Bergen, Norway)
The Barents Sea sits in the main corridor of travelling weather systems, steered by the atmospheric jet stream, that carry warm air and moisture from the North Atlantic towards the Arctic. As such, conditions in the Barents are sensitive to factors that influence the speed, position and path of the jet. At the same time, ocean-driven changes in sea surface temperatures and sea ice cover may be felt by the atmosphere, with the possibility of teleconnections communicating these signals to other parts of the globe. Using observational and modelling results, this presentation will give an overview of how the atmosphere drives variability and change in the Barents region, and whether the Barents can affect climate and weather further afield. Open questions concerning the ability of climate models to capture the relevant processes and the implications for constraining future change in the region will be explored.
Monika Kędra (Institute of Oceanology Polish Academy of Sciences, Poland)
Arctic marine benthos and their food webs play an important role in overall ecosystem functioning including production and organic matter and energy cycling. Benthic organisms are considered temporal couplers of resources, especially in ecosystems with strong seasonality and seasonal organic matter pulses to the sea floor. In the Arctic predicted changes in primary production patterns are expected to impact pelagic-benthic coupling processes, and thus benthos and their food webs, and thus whole ecosystem functioning. In this talk I review and compare the benthic communities and their functioning in the Pacific and Atlantic sectors of the Arctic Ocean. I discuss the responses of benthic organisms and their trophic relations to the on-going and predicted changes in the quality and quantity of organic matter delivered to the sea floor. Potential consequences of possible changes in benthic communities for the ecosystem functioning are considered.
Kristina Brown (University of Manitoba, Canada)
Unprecedented rapid changes in the Arctic Ocean are impacting its coupled physical and biogeochemical systems. Sea ice loss, together with increases in river input and coastal erosion, are altering both the Arctic’s freshwater system and its carbon cycle in tandem. Such ongoing changes will play an important role in the global climate system, in particular impacting the Arctic Ocean’s ability to act as a CO2 sink for atmospheric CO2. In this talk I will look at the impact of freshwater on the Arctic Ocean carbon cycle at a variety of scales to address the core question, “how does freshwater impact CO2 exchanges in the surface ocean?”. At the pan-Arctic scale, I discuss the dual roles of regionality and seasonality of freshwater sources in establishing the backdrop for the biogeochemical processes that constrain carbon cycling in the surface ocean. Then I narrow the view to the regional frame, presenting new insights about the smaller northern rivers that drain the Arctic coastal margins. Lastly, I will discuss some of the challenges to freshwater and carbon monitoring in local river systems to demonstrate where community supported observational projects have been successful in filling critical gaps. Looking at this question from multiple perspectives allows us to see the importance of scalability in the design of observation systems and the absolute necessity for partnerships with northern communities to meet the challenges of Arctic research.
Marcel Nicolaus (Alfred-Wegener-Institute, Germany)
Arctic sea ice has decreased in extent and thickness during all seasons. The ice cover changed to a younger and more seasonal ice pack with different physical properties. However, it is still challenging to characterize sea ice and snow properties and processes during all seasons in relation to feedbacks with the atmosphere and the ocean. As a result, numerical simulations and forecasts as well as satellite data retrieval algorithms still have large uncertainties. During the Multidisciplinary drifting Observatory for the Study of Arctic Climate, MOSAiC, sea ice and snow properties were observed over a full annual cycle in 2019/2020. In this presentation, I will summarize and review the sea ice and snow conditions over the annual cycle based on MOSAiC results. I will present mean properties of key parameters ranging from the lowest atmosphere, through snow and sea ice, into the upper ocean. The results indicate that the contrasts of different sea ice types in the Arctic Ocean diminish from autumn to spring. New sea ice types, pressure ridges and snow distributions need to be considered more explicitly when describing and modelling atmosphere-ice-ocean interactions. This will help to improve our understanding of the coupled Arctic system and lead to improved forecasts.
Khuong V. Dinh (University of Oslo, Norway)
Global warming, marine heatwaves, and ocean acidification can affect physical and ecological processes in Arctic marine ecosystems. These processes can have knock-on effects on the uptake, fate, and effects of persistent organic pollutants and contaminants of emerging Arctic concern in Arctic marine organisms. Conversely, toxicant exposure can affect species’ adaptability to climate change. Here, we have summarized how climate change affect physical and ecological processes in Arctic marine biota and food webs.
1) Global use and regulations of pollutants still are the main drivers for levels in Arctic biota, increased incidents of positive states of the North Atlantic Oscillation (NAO+) result in the increased long-range transport of pollutants and biomagnification in Arctic food webs.
2) Northward range‐shifting species act as biovectors for pollutants into Arctic marine food webs, leading to elevated levels.
3) Dietary shifts can alter pollutant transfer in the food webs. Reductions in body condition are associated with pollutant increase in some biota.
4) The interaction of warming, ocean acidification and pollutants can result in antagonistic, additive or synergistic effects depending on the species, life stages, and the magnitude and duration of stressor exposure. Furthermore, multiple stressors studies have predominantly been conducted during summer months, however, we show that we show that effects and interactions of these stressors can often differ between winter and other seasons.
Studies that are performed across a series of stress levels, exposure conditions in multiple seasons will be particularly important to tease apart the effects of climate change on pollutant toxicity and accumulation. A step further is to identify the ecological tipping points of Arctic marine species and food webs in complex interactions of climate change and pollutants, which are crucial for more comprehensive ecological risk assessments and management.
Christian März (University of Bonn, Germany)
Marine sediments are excellent recorders of past environmental conditions – but they are also biogeochemical reactors. This “duality” presents a challenge for paleo-environmental reconstructions: On the one hand, certain sediments are more prone to diagenetic overprint than others – on the other hand, certain depositional conditions give rise to more intense diagenetic reactions. Within the NERC-funded project ChAOS (The Changing Arctic Ocean Seafloor), and in collaboration with the Nansen Legacy project, an interdisciplinary team of scientists studied the shallow seafloor of the Barents Sea to unravel the diagenetic processes occurring in these deposits, and to inform paleo-environmental reconstructions on sediment cores from this Arctic shelf region. In this talk, I will present an overview of our findings, focusing on factors that control the degradation/dissolution versus preservation of various sediment components, including organic matter, biogenic carbonate, biogenic opal and metals like iron and manganese.
Maxime Geoffroy (Memorial University of Newfoundland, Canada)
The Arctic is warming up to four times faster than the rest of our planet, resulting in a drastic reduction in sea ice cover and an increase in water temperatures. These changes strongly modify the habitat of the fish thriving under the extreme conditions prevailing in the Arctic and allow boreal species from the North Atlantic and Pacific to migrate further North, potentially opening new fishing grounds. However, these changes do not occur at the same rate across all Arctic regions. The Canadian Arctic remains mostly dominated by endemic species, while the Barents Sea experiences a rapid borealization of its fauna. Based on acoustic-trawl surveys conducted in both regions, this presentation will contrast the diversity and distribution of fish in the Canadian Arctic and the Barents Sea. It will further discuss current and future changes in their fish and fisheries ecosystems.
Janne Søreide (University Centre in Svalbard, Norway)
One of the distinct features of the European Arctic is the massive influx of warm Atlantic water, carrying huge amounts of nutrients and boreal plankton north. The result is a diverse and rich zooplankton community in the Svalbard-Barents Sea region, where a dominance of North Atlantic species mirrors strong influence of Atlantic water. The continuous supply of boreal zooplankton exposes the European Arctic zooplankton community to a severe borealisation, also referred to as “Atlantification”. However, the long, dark winter combined with the short summer make it hard for most of these boreal species to survive and thrive and we observe a reset to a more Arctic zooplankton community over the course of the winter. With global warming, sea ice extent and thickness are reduced while the primary production season in the high Arctic is extending. Whether this will increase survival rate and reproductive success of boreal species in the European Arctic is one of the key questions that will be discussed in this talk.
Karley Campbell (University of Tromsø The Arctic University of Norway, Norway)
Primary producers are the basis of ecosystems. Through their photosynthetic activity they provide the organic carbon necessary to support higher trophic levels while also influencing the movement of climate relevant gases like CO2 between the atmosphere and ocean. In the Arctic, sea ice is a prominent yet rapidly changing feature of the marine ecosystem that both hinders photosynthetic activity and provides new habitat opportunities. Here we review the current distribution of - and ongoing changes to - primary producers and their production in the Arctic Ocean. Important considerations for studying the production potential of sea ice are also investigated; including the need to represent a diversity of microhabitats within the ice and consider the role of respiration associated with them.
Igor V. Polyakov (University of Alaska, Fairbanks, USA)
High-latitude atlantification is caused by increased warm, salty sub-Arctic inflows, which affect oceanic stratification, increase heat fluxes, and decrease sea ice in the Eurasian Basin of the Arctic Ocean. These inflows from the North Atlantic across the Nordic Seas are modulated by the atmospheric Arctic Dipole (AD), linked with anticyclonic winds over North America and cyclonic winds over Eurasia. The alternating atmospheric AD regimes establish a "switchgear mechanism". Switchgear decreased northward inflows across Fram Strait and increased inflows throughout the Barents Sea between 2007 and 2021, which was connected with the positive AD regime. A stronger Arctic Ocean circulation and freshwater redistribution into the Amerasian Basin associated with increased stratification and decreased oceanic heat fluxes are other consequences of the positive AD regime. These processes contributed to a hiatus in Arctic sea-ice loss after 2007. A transition to a new negative AD regime will likely accelerate the Arctic sea-ice decline, with consequences for the Arctic climate system.