Søren Rysgaard

Søren Rysgaard
Aarhus University | AU

PhD
https://arctic.au.dk; https://gios.org; https://isaaffik.org; https://asp-net.org

About

341
Publications
79,708
Reads
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15,985
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Introduction
Professor and Canada Excellence Research Chair (CERC) Laureate. Research interests: Marine microbiology and biogeochemistry in Arctic sea ice, ocean and sediments. Understanding carbon and nutrient cycling in Arctic marine ecosystems, sea ice processes and glacier-fjord-ocean interactions. Global change. Scientific leader - Arctic Science Partnership (ASP). Founding Director – Greenland Climate Research Centre (Greenland), Arctic Research Centre (Denmark).
Additional affiliations
July 2012 - present
Aarhus University
Position
  • Professor
September 2011 - present
Greenland Institute of Natural Resources
Position
  • Professor (Associate)
August 2011 - August 2018
University of Manitoba
Position
  • Professor

Publications

Publications (341)
Article
Full-text available
The waters on the West Greenland continental shelf and slope play an important role in the global climate system with their link to the subpolar North Atlantic Ocean circulation system and the Greenland Ice Sheet. Lately, low temperature waters on the West Greenland shelf have been observed as far south as ∼64°N and associated with a cold and relat...
Article
Full-text available
Climate change is rapidly altering the Arctic environment. Although long-term environmental observations have been made at a few locations in the Arctic, the incomplete coverage from ground stations is a main limitation to observations in these remote areas. Here we present a wind and sun powered multi-purpose mobile observatory (ARC-MO) that enabl...
Article
Full-text available
Accelerated melting of ice in Polar Regions due to global warming increases freshwater input to coastal waters from marine terminating glaciers. Lack of measurements near the glacier terminus limits our knowledge of the mixing processes between freshwater and the underlying ocean. We present a low-cost (< € 3200) and lightweight (2.6 kg) drone-depl...
Preprint
The ice bridge in Nares Strait is a well-known phenomenon that affects the liquid and solid freshwater flux from the Arctic Ocean through the strait and controlling the downstream North Water polynya in the northern Baffin Bay. Recently, the ice bridge has been in a state of decline, either breaking up earlier or not forming at all, and thereby inc...
Article
Full-text available
The interview survey conducted in Ilulissat, Ilimanaq, and Qasigiannguit in Greenland during March–April 2019 showed that the local fishers are changing fishing strategies and adapting to a changing environment caused by climate change. The main fjord of Ilulissat Icefjord is usually filled with icebergs year-round, making it impossible to navigate...
Article
Full-text available
The net productivity of sea ice is determined by the physical and geochemical characteristics of the ice–ocean system and the activity of organisms inhabiting the ice. Differences in habitat suitability between first-year and multi-year sea ice can affect the ice algal community composition and acclimation state, introducing considerable variabilit...
Article
Full-text available
Sea ice continues to decline across many regions of the Arctic, with remaining ice becoming increasingly younger and more dynamic. These changes alter the habitats of microbial life that live within the sea ice, which support healthy functioning of the marine ecosystem and provision of resources for human-consumption, in addition to influencing bio...
Article
Full-text available
Although studies of biogeochemical processes in polar sea ice have been increasing, similar research on relatively warm low-salinity sea ice remains sparse. In this study, we investigated biogeochemical properties of the landfast sea ice cover in the brackish Bothnian Bay (Northern Baltic Sea) and the possible role of this sea ice in mediating the...
Article
Full-text available
An influx of glacial meltwater has the ability to alter the properties of marine surface waters and their ability to exchange CO2 through changes to water column stratification and the inorganic carbon system. Here, we report how inputs of meteoric water affect the physical and biogeochemical properties of both the water column and the sea ice cove...
Article
As climate change brings reduced sea ice cover and longer ice-free summers to the Arctic, northern Canada is experiencing an increase in shipping and industrial activity in this sensitive region. Disappearing sea ice, therefore, makes the Arctic region susceptible to accidental releases of different types of oil and fuel pollution resulting in a pr...
Article
Full-text available
Vertical mixing of upper water masses in Arctic fjords is important for circulation and transport of nutrients and heat. However, the distribution of turbulent mixing is poorly known. Here we present hydrographic and microscale turbulence measurements from six fjords in Northwestern (69°N–75°N) Greenland. Water mass distributions showed the presenc...
Article
Oil spills in Arctic marine environments are expected to increase concurrently with the expansion of shipping routes and petroleum exploitation into previously inaccessible ice-dominated regions. Most research on oil biodegradation focusses on the bulk oil, but the fate of the water-accommodated fraction (WAF), mainly composed of toxic aromatic com...
Article
Full-text available
The ice bridge that forms seasonally across Nares Strait impedes the southward transport of sea ice from the Lincoln Sea to Baffin Bay and contributes to the maintenance of the North Water Polynya. Previous studies have quantified how the bridge affects ice export and highlighted a long term decline in the duration of the bridge; however, the speci...
Article
Full-text available
The rapid warming of our planet has resulted in accelerated melting of ice in polar regions. Currently we have limited knowledge on how, where and when the surface meltwater layer is mixed with the underlying ocean due to lack of observations in these remote areas. We present a lightweight (17 kg) and low-cost (6000€) instrument for autonomous prof...
Article
Full-text available
Hudson Bay, at the southern margin of the Arctic Ocean, receives nearly one-third of Canada’s river discharge and approximately 5.5 Tg of riverine dissolved organic carbon (DOC) annually. Riverine DOC fluxes to Hudson Bay are expected to increase with climate change, but how this increase will influence the biogeochemistry of the coastal waters is...
Article
Full-text available
During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed sediment-laden sea ice were encountered unexpectedly in southern Hudson Bay and presented difficult navigation conditions for the Canadian Coast Guard Ship Amundsen. An aerial survey of one of these floes revealed a maximum ridge height of 4.6 m and an av...
Article
Full-text available
The pelagic spring bloom is essential for Arctic marine food webs, and a crucial driver of carbon transport to the ocean depths. A critical challenge is understanding its timing and magnitude, to predict its changes in coming decades. Spring bloom onset is typically light-limited, beginning when irradiance increases or during ice breakup. Here we r...
Article
The Arctic Ocean is overwhelmingly forced by its lateral boundaries, and interacts with, the global system. For the development of nested conceptual models of the Arctic Ocean ecosystem we here choose the full pan-Arctic as our focal scale. Understanding the pan-Arctic scale, however, requires that we look at the underlying scales of its major comp...
Article
Full-text available
A 2-year-long time series of currents and acoustic backscatter from an acoustic Doppler current profiler, moored over the eastern Beaufort Sea continental slope from October 2003 to September 2005, were used to assess the dynamics and variability of the sound-scattering layer. It has been shown that acoustic backscatter is dominated by a synchroniz...
Article
Climate changes in the Arctic may weaken the currently tight pelagic-benthic coupling. In response to decreasing sea ice cover, arctic marine systems are expected to shift from a ‘sea-ice algae–benthos' to a ‘phytoplankton-zooplankton’ dominance. We used mollusc shells as bioarchives and fatty acid trophic markers to estimate the effects of the red...
Article
Full-text available
Buoyant freshwater released at depth from under Greenland's marine-terminating glaciers gives rise to vigorous buoyant discharge plumes adjacent to the termini. The water mass found down fjord formed by mixing of buoyant subglacial freshwater and ambient fjord water and subsequent modification by glacial ice melt in the ice mélange is referred to a...
Preprint
Full-text available
A two-year-long time series of currents and acoustic backscatter from an Acoustic Doppler Current Profiler, moored over the eastern Beaufort Sea continental slope from October 2003 to September 2005, were used to assess dynamics and variability of the sound-scattering layer. It has been shown that acoustic backscatter is dominated by a synchronized...
Article
Full-text available
The accelerated melt of the Greenland Ice Sheet has been linked to a sudden increase in the presence of warm subsurface coastal water in west Greenland. Yet pathways of warm coastal water along the entire west Greenland coast have remained largely unstudied. Here we present the first, near‐synoptic hydrographic observations at both the continental...
Article
Full-text available
Icebergs account for approximately half of the freshwater ux from the Greenland Ice Sheet and they can impact marine ecosystems by releasing nutrients and sediments into the ocean as they drift and melt. Parameterizing iceberg uxes of nutrients and sediments to fjord and ocean waters remains a difficult task due to the complexity of ice-ocean inter...
Article
Full-text available
The Green Edge initiative was developed to investigate the processes controlling the primary productivity and fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiq...
Data
This outreach video made by the very talented Caspar Haarløv (casparhaarloev.dk) shows the Ice Drone in action during its first field tests near Nuuk, Greenland in January 2019.
Article
Full-text available
The ecological impacts of meltwater produced by icebergs and sea ice in the waters around Greenland are poorly understood, due in part to limited observations. Current field sampling methods are resource and labor-intensive, and not without significant risk. We developed a small, unoccupied, and robotic platform to retrieve ice samples, while simul...
Preprint
Full-text available
The ecological impacts of meltwater produced by icebergs and sea ice in the waters around Greenland are poorly understood, due in part to limited observations. Current field sampling methods are resource and labor-intensive, and not without significant risk. We developed a small, unoccupied, and robotic platform to retrieve ice samples, while simul...
Article
Full-text available
The Green Edge initiative was developed to investigate the processes controlling the primary productivity and the fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Q...
Article
Full-text available
Rapid mass loss from the Greenland Ice Sheet (GrIS) is affecting sea level and, through increased freshwater and sediment discharge, ocean circulation, sea-ice, biogeochemistry, and marine ecosystems around Greenland. Key to interpreting ongoing and projecting future ice loss, and its impact on the ocean, is understanding exchanges of heat, freshwa...
Article
Full-text available
Sea ice in part controls surface water properties and the ocean-atmosphere exchange of greenhouse gases at high latitudes. In sea ice, gas exists dissolved in brine and as air bubbles contained in liquid brine inclusions or as bubbles trapped directly within the ice matrix. Current research on gas dynamics within the ocean-sea ice-atmosphere interf...
Article
Full-text available
Bathymetry measurements are needed in shallow, near-shore environments to estimate the potential distribution of macroalgae and seagrass, which contribute to oceanic carbon sinks in Greenland and other Arctic locations. Additionally, ocean current observations near icebergs and marine-terminating glaciers are necessary to estimate their melt rates....
Article
Full-text available
Few combined measurements of primary and bacterial productivity exist for Arctic sea ice, particularly during winter, making it difficult to assess the relative importance of these microbial processes for carbon cycling in sea ice. Furthermore, the occurrence of calcium carbonate (CaCO 3 ), though well-documented in sea ice, is poorly described for...
Article
Full-text available
Past research in seasonally ice-covered Arctic seas has suggested that ice algae play a role in reducing dissolved inorganic carbon (DIC) during spring, preconditioning surface waters to low dissolved CO 2 (pCO 2sw ), and uptake of atmospheric CO 2 during the ice-free season. The potential role of under-ice phytoplankton blooms on DIC and pCO 2sw h...
Article
Full-text available
The accuracy of sea ice algal production estimates is influenced by the range of melting procedures used in studies to obtain a liquid sample for incubation, particularly in relation to the duration of melt and the approach to buffering for osmotic shock. In this research, ice algal photophysiology from 14C incubations was compared in field samples...
Article
Full-text available
Capelin (Mallotus villosus) is an important trophic node in many Arctic and sub-Arctic ecosystems. In Godthåbsfjord, West Greenland, the zooplankton community has been shown to change significantly from the inner part of the fjord, which is impacted by several glaciers to the shelf outside the fjord. To what extent this gradient in zooplankton comp...
Article
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A portion of the freshwater transport through Fram Strait consists of low-salinity Pacific-derived Arctic water flowing southward along the east coast of Greenland. The pathways of this water are currently unclear. An Ice Tethered Profiler deployed over the southeastern Wandel Sea shelf (northeast Greenland) in May 2015 collected a profile every 3...
Article
Full-text available
The biomarker IP 25 and fossil diatom assemblages preserved in seafloor sediments are commonly used as proxies for paleo Arctic sea-ice reconstructions, but how their production varies over the seasons and is exported to the sediment remains unclear. We analyzed IP 25 concentrations and diatom assemblages from a 5-week consecutive series of sea-ice...
Article
Full-text available
The biomarker IP25 and fossil diatom assemblages preserved in seafloor sediments are commonly used as proxies for paleo Arctic sea-ice reconstructions, but how their production varies over the seasons and is exported to the sediment remains unclear. We analyzed IP25 concentrations and diatom assemblages from a 5-week consecutive series of sea-ice c...
Poster
Sea ice is a heterogeneous porous media consisting of an ice matrix in which is embedded liquid brine inclusions and air bubbles. The presence of a brine network and air inclusions strongly influence the electromagnetic properties of the ice, thus impacting detection capability, and are often sites of biological activity. Furthermore, the abundance...
Chapter
Full-text available
Arctic marine ecosystems provide numerous benefits and services of economic, societal and ecological value, including the provision of food resources, the conservation of biodiversity, carbon storage and nutrient recycling, among others. The Arc3Bio project combines the multidisciplinary skills of several experts to evaluate how climate variability...
Chapter
Full-text available
Arctic marine ecosystems provide numerous benefits and services of economic, societal and ecological value, including the provision of food resources, the conservation of biodiversity, carbon storage and nutrient recycling, among others. The Arc3Bio project combines the multidisciplinary skills of several experts to evaluate how climate variability...
Conference Paper
Full-text available
Outreach actions are important boundary processes [1] that are designed to identify specific ways to facilitate and to enhance the interactions between science and policy, and most importantly, to influence human attitudes and associated policy decisions [2]. In June of 2018, UiT, the Arctic University of Norway, hosted the 2018 OUTREACH Expedition...
Article
Full-text available
Pacific water contributes significantly to the Arctic Ocean freshwater budget. Recent increases in Arctic freshwater flux, also affected by the Pacific-derived Arctic water, impact the Atlantic overturning circulation with implications for global climate. The interannual variability of the Pacific water outflow remains poorly understood, partly due...
Article
Full-text available
Fjords form the gateway between the open ocean and the Greenland Ice Sheet (GIS) and consequently play a crucial role for the stability of the Ice Sheet. Hydrographic observations, especially with seasonal resolution, from these fjords are limited making it difficult to assess linkages between the fjord, coastal water masses and freshwater discharg...
Article
Full-text available
Sea-ice ecosystems are among the most extensive of Earth’s habitats; yet its autotrophic and heterotrophic activities remain poorly constrained. We employed the in situ aquatic eddy-covariance (AEC) O2 flux method and laboratory incubation techniques (H¹⁴CO3⁻, [³H] thymidine and [³H] leucine) to assess productivity in Arctic sea-ice using different...
Article
In pristine sea ice-covered Arctic waters the potential of natural attenuation of oil spills has yet to be uncovered, but increasing shipping and oil exploitation may bring along unprecedented risks of oil spills. We deployed adsorbents coated with thin oil films for up to 2.5 month in ice-covered seawater and sea ice in Godthaab Fjord, SW Greenlan...