West Coast Of Greenland Research Articles

Modelling subglacial discharge and its influence on ocean heat transport in Arctic fjords

Tidewater outlet glaciers are directly connected to the ocean via ice walls or floating shelves. Melting and freezing of ice, runoff, englacial, and subglacial discharge of freshwater and ocean heat transport are therefore potential feedback processes between glacial ice flow and ocean circulation. Subglacial discharge occurs at the base of tidewater glacier outlets where out-flowing freshwater forms a convective buoyant plume ascending close to the glacier face and, due to entrainment, transports relatively warm and saline ambient bottom water up towards the surface. Plume dynamics, typically occurring at sub-grid scales in regional ocean models, therefore has to be parameterized in areas where ice-ocean interactions occur, as for example in Arctic fjords. Here, we develop and analyze a new simple boundary condition of subglacial discharge where entrainment-induced transport between the subsurface and surface layer is described. A sensitivity study showed that subglacial discharge increased ocean heat transport near the glacier whereas the impact from plume-entrainment became relatively small further from the glacier. Subglacial discharge was shown to have a significant influence on surface concentrations. The impact from subglacial discharge was demonstrated in a regional model of Godthabsfjord (64°N), located at the west coast of Greenland, where surface concentrations near the glacier were shown to be sensitive to subglacial discharge in accordance with observations.

Community composition of epibenthic megafauna on the West Greenland Shelf

Epibenthic organisms are a critical component of the marine environment, functioning as ecosystem engineers, habitat and food for other organisms. Our knowledge of the diversity, complexity and sensitivities of these habitats is limited, particularly at higher latitudes and greater depths. The West Coast of Greenland is the site of a commercially important shrimp trawl fishery, but there are few published records describing the benthic community structure of the region. Here we report results from benthic camera surveys conducted at 119 sites, over 3 years, spanning 1400 km of the West Greenland continental shelf (61–725 m depth). A total of 29 classes of epibenthic taxa were identified from the images. There are significant differences of composition and diversity in sites with hard and soft substrate. Hard-substrate communities are relatively diverse with higher abundances and are characterised by sessile, attached groups such as Hydrozoa, Anthozoa, Bryozoa and Porifera. Soft-sediment sites are less diverse and dominated by Polychaeta and have specialist Malacostraca such as the commercially exploited shrimp, Pandalus borealis. Distribution patterns and variation in epibenthic megafauna are related to substrate and the environmental parameters depth, temperature and current speed. This study represents the first quantitative characterisation of epibenthic megafaunal assemblages on the West Greenland continental shelf. These data constitute an important baseline, albeit in a region heavily impacted by trawl fisheries, and demonstrate the utility of benthic photography for examining and monitoring seabed diversity and change.

Direct current (DC) resistivity and induced polarization (IP) monitoring of active layer dynamics at high temporal resolution

With permafrost thawing and changes in active layer dynamics induced by climate change, interactions between biogeochemical and thermal processes in the ground are of great importance. Here, active layer dynamics have been monitored using direct current (DC) resistivity and induced polarization (IP) measurements at high temporal resolution and at a relatively large scale at a heath tundra site on Disko Island on the west coast of Greenland (69°N). At the field site, the active layer is disconnected from the deeper permafrost, due to isothermal springs in the region. Borehole sediment characteristics and subsurface temperatures supplemented the DC-IP measurements. A time-lapse DC-IP monitoring system has been acquiring at least six datasets per day on a 42-electrode profile with 0.5m electrode spacing since July 2013. Remote control of the data acquisition system enables interactive adaptation of the measurement schedule, which is critically important to acquire data in the winter months, where extremely high contact resistances increase the demands on the resistivity meter. Data acquired during the freezing period of October 2013 to February 2014 clearly image the soil freezing as a strong increase in resistivity. While the freezing horizon generally moves deeper with time, some variations in the freezing depth are observed along the profile. Comparison with depth-specific soil temperature indicates an exponential relationship between resistivity and below-freezing temperature. Time-lapse inversions of the full-decay IP data indicate a decrease of normalized chargeability with freezing of the ground, which is the result of a decrease in the total unfrozen water and of the higher ion concentration in the pore-water. We conclude that DC-IP time-lapse measurements can non-intrusively and reliably image freezing patterns and their lateral variation on a 10–100m scale that is difficult to sample by point measurements. In combination with laboratory experiments, the different patterns in resistivity and chargeability changes will enable the disentanglement of processes (e.g., fluid migration and freezing, advective and diffusive heat transport) occurring during freezing of the ground. The technology can be expanded to three dimensions and also to larger scale.

In the Warming Arctic Seas

In the Warming Arctic Seas

Extreme moisture transport into the Arctic linked to Rossby wave breaking

AbstractThe transport of moisture into the Arctic is tightly connected to midlatitude dynamics. We show that the bulk of the transient poleward moisture transport across 60°N is driven by extreme transport (fluxes greater than the 90th percentile) events. We demonstrate that these events are closely related to the two types of Rossby wave breaking (RWB)—anticyclonic wave breaking (AWB) and cyclonic wave breaking (CWB). Using a RWB tracking algorithm, we determine that RWB can account for approximately 68% of the extreme poleward moisture transport by transients across 60°N in winter and 56% in summer. Additional analysis suggests that the seasonality of such RWB‐related moisture transport is determined approximately equally by (1) the magnitude of transport (which is largely a function of the background moisture gradient) and (2) the frequency of RWB occurrence. The seasonality of RWB occurrence is, in turn, tied to the seasonal variation of the latitude of the jet streams—AWB‐related (CWB‐related) transport occurs more frequently when the jet is shifted poleward (equatorward). The interannual variability of RWB‐related transport across 60°N in winter is shown to be strongly influenced by climate variability captured by the El Niño/Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO). In the positive (negative) phase of ENSO, AWB transports less (more) moisture through the Bering Strait and CWB transports more (less) through western Canada. In the positive (negative) phase of the NAO, AWB transports more (less) moisture through the Norwegian Sea and CWB transports less (more) along the west coast of Greenland. These results highlight that low‐frequency climate variability outside of the polar regions can influence the Arctic water vapor by modulating extreme synoptic transport events.

Seasonal variability of the warm Atlantic water layer in the vicinity of the Greenland shelf break

AbstractThe warmest water reaching the east and west coast of Greenland is found between 200 and 600 m. While important for melting Greenland's outlet glaciers, limited winter observations of this layer prohibit determination of its seasonality. To address this, temperature data from Argo profiling floats, a range of sources within the World Ocean Database, and unprecedented coverage from marine‐mammal borne sensors have been analyzed for the period 2002–2011. A significant seasonal range in temperature (~1‐2°C) is found in the warm layer, in contrast to most of the surrounding ocean. The phase of the seasonal cycle exhibits considerable spatial variability, with the warmest water found near the eastern and southwestern shelf break toward the end of the calendar year. High‐resolution ocean model trajectory analysis suggests the timing of the arrival of the year's warmest water is a function of advection time from the subduction site in the Irminger Basin.

Sedimentary successions and palynoevent stratigraphy from the non-marine Lower Cretaceous to the marine Upper Cretaceous of the Nuussuaq Basin, West Greenland

Abstract The Nuussuaq Basin, West Greenland, comprises the only exposures of Mesozoic sedimentary strata on the west coast of Greenland. The Nuussuaq Basin exposes Cretaceous and Paleocene siliciclastic strata, referred to as the Nuussuaq Group, overlain by volcanic rocks, mainly of Paleocene age, referred to as the West Greenland Basalt Group. Regional seismic studies indicate that the Cretaceous strata of the Nuussuaq Basin may be correlated to the Appat and Kangeq seismic sequences in the offshore basins. The present paper re-investigates five profiles, trending roughly east-west, from northern Disko to southern Svartenhuk Halvo, which exemplify the litho- and biostratigraphy, with a focus on the pre-Campanian deposits. The oldest exposed strata belong to the non-marine Kome Formation of possible Albian age. Dinoflagellate cysts that indicate brackish water conditions characterize the Albian and early Cenomanian, whereas marine dinoflagellate cysts occur in the latest Cenomanian, and in younger deposits. The dating of the Nuussuaq Group is based mostly on palynology, supported by scarce ammonites. A new, refined palynoevent stratigraphy is established, based on the study of many new and older sections. The new palynoevent stratigraphy allows a better correlation between widely spaced onshore sections and offshore successions, and provides an improved basis for paleogeographical interpretations.

A crustal model for northern Melville Bay, Baffin Bay

AbstractThe interpretation of seismic refraction and gravity data acquired in 2010 gives new insights into the crustal structure of the West Greenland coast and the adjacent deep central Baffin Bay basin. Underneath Melville Bay, the depth of the Moho varies between 26 and 17 km. Stretched continental crust with a thickness of 25 to 14 km and deep sedimentary basins are present in this area. The deep Melville Bay Graben contains an up to ~11 km thick infill of consolidated and unconsolidated sediments with velocities of 1.6 to 4.9 km/s. Seaward, at the ~60 km wide transition between oceanic and stretched continental crust, a mount‐shaped magmatic structure is observed, which most likely formed prior to the initial formation of oceanic crust. The up to 4 km high magmatic structure is underlain by a ~2 km thick and ~50 km wide high velocity lower crust. More to the west, in the oceanic part of the Baffin Bay basin, we identify a two‐layered, 3.5 to 6 km thin igneous oceanic crust with increasing thickness toward the shelf. Beneath the oceanic crust, the depth of the Moho ranges between 11.5 and 13.5 km. In the western part of the profile, oceanic layer 3 is unusually thin (~1.5 km) A possible explanation for the thin crust is accretion due to slow spreading, although the basement is notably smooth compared to the basement of other regions formed by ultra‐slow spreading. The oceanic crust is underlain by partly serpentinized upper mantle with velocities of 7.6 to 7.8 km/s.

Role of Resolved and Parameterized Eddies in the Labrador Sea Balance of Heat and Buoyancy

Abstract Deep convection in the Labrador Sea is an important component of the global ocean ventilation. The associated loss of heat to the atmosphere from the interior of the sea is thought to be mostly supplied by mesoscale eddies, generated either remotely or as a result of convection itself—processes that are not resolved by low-resolution ocean climate models. The authors first employ a high-resolution (°) ocean model forced with high-resolution (33 km, 3 h) atmospheric fields to further elaborate on the role of mesoscale eddies in maintaining the balance of heat and buoyancy in the Labrador Sea. In general agreement with previous studies, it is found that eddies remove heat along the coast and supply it to the interior. Some of the eddies that are generated because of the barotropic instability off the west coast of Greenland are recaptured by the boundary current. In the region of deep convection, the convergence of heat and buoyancy by eddies significantly increases with the deepening of the winter mixed layer. In addition, the vertical eddy flux plays an important part in the heat budget of the upper Labrador Sea, accounting for up to half of the heat loss to the atmosphere north of 60°N. A low-resolution (1°) model with parameterized eddies is then applied to show that it does capture, qualitatively, the general structure of eddy buoyancy advection along the Labrador Current. However, the 1° model is deficient in this regard in the most eddy active region off the west coast of Greenland, although some improvements can be made by forcing it with the high-resolution atmospheric fields.

An autonomous adaptive low-power instrument platform (AAL-PIP) for remote high-latitude geospace data collection

Abstract. We present the development considerations and design for ground-based instrumentation that is being deployed on the East Antarctic Plateau along a 40° magnetic meridian chain to investigate interhemispheric magnetically conjugate geomagnetic coupling and other space-weather-related phenomena. The stations are magnetically conjugate to geomagnetic stations along the west coast of Greenland. The autonomous adaptive low-power instrument platforms being deployed in the Antarctic are designed to operate unattended in remote locations for at least 5 years. They utilize solar power and AGM storage batteries for power, two-way Iridium satellite communication for data acquisition and program/operation modification, support fluxgate and induction magnetometers as well as a dual-frequency GPS receiver and a high-frequency (HF) radio experiment. Size and weight considerations are considered to enable deployment by a small team using small aircraft. Considerable experience has been gained in the development and deployment of remote polar instrumentation that is reflected in the present generation of instrumentation discussed here. We conclude with the lessons learned from our experience in the design, deployment and operation of remote polar instrumentation.

Seasonal migration, vertical activity, and winter temperature experience of Greenland halibut Reinhardtius hippoglossoides in West Greenland waters

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 508:211-222 (2014) - DOI: https://doi.org/10.3354/meps10874 Seasonal migration, vertical activity, and winter temperature experience of Greenland halibut Reinhardtius hippoglossoides in West Greenland waters Jesper Boje1, Stefan Neuenfeldt1, Claus Reedtz Sparrevohn2, Ole Eigaard1, Jane W. Behrens1,* 1Technical University of Denmark, National Institute of Aquatic Resources, Kavalergaarden 6, 2920 Charlottenlund, Denmark 2Danish Pelagic Producers Organization, HC Andersens Boulevard 37, 1553 Copenhagen, Denmark *Corresponding author: jabeh@aqua.dtu.dk ABSTRACT: The deep-water flatfish Greenland halibut Reinhardtius hippoglossoides (Walbaum) is common along the West Greenland coast. In the northwestern fjords, Greenland halibut is an important socio-economic resource for the Greenland community, but due to the deep and partly ice-covered environment, very little is known about its behavior and habitat characteristics. We tagged adult Greenland halibut in the waters off Ilulissat with electronic data storage tags that collected information on depth, temperature, and time. Although clear differences between individuals in migration and vertical behavior were present, we discovered a consistent seasonal migration from the relatively shallow-water Disko Bay area into the deep waters of the Ilulissat Icefjord, where the fish resided in the winter months before returning to Disko Bay. Vertical activity was pronounced at both locations, with fish covering vertical distances of up to 100 m within 15 min. During the winter months, the fish experienced temperatures between ca. 0 and 4°C, with most experiencing temperatures of 2 to 3°C. Irrespective of year and quarter of the year, the fish experienced warmer water and a broader range of temperatures when resident in Disko Bay (mean range 2.6°C) than when resident in the ice fjord (mean range 1.4°C). Using the tagged halibut as a ‘live tool,’ we show that parts of the ice fjord are hundreds of meters deeper than previously thought. We also document the first seawater temperature measurements made beneath the Jakobshavn Isbræ outlet glacier, revealing a positive relationship between depth and temperature for the upper 600 m and a between-year variation in temperatures beneath the ice sheet in 2001, 2002, and 2003. KEY WORDS: Archival tags · Arctic · Behavior · Habitat · Seawater temperatures · Swimming speed Full text in pdf format PreviousNextCite this article as: Boje J, Neuenfeldt S, Sparrevohn CR, Eigaard O, Behrens JW (2014) Seasonal migration, vertical activity, and winter temperature experience of Greenland halibut Reinhardtius hippoglossoides in West Greenland waters. Mar Ecol Prog Ser 508:211-222. https://doi.org/10.3354/meps10874 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 508. Online publication date: August 04, 2014 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2014 Inter-Research.

Description of diatoms from the Southwest to West Greenland coastal and open marine waters

Detailed studies on sub-Arctic and Arctic marine diatom assemblages contribute to the understanding of spatial distribution patterns and their physical drivers. In this study, diatom species were analyzed from water samples collected with a Niskin bottle rosette combined with a CTD along the West Greenland coast (63°58′N–71°08′N and 50°49′W–59°06′W) during summer 2007. Diatom community was represented mainly by three genera Thalassiosira, Fragilariopsis, and Chaetoceros and linked to observed hydrographic and environmental conditions. Thalassiosira spp. were common in coastal waters (particularly Godthabsfjord) and linked to increased surface water temperature, typical of summer water stratification in West Greenland. Fragilariopsis spp., along with other dominant species associated with higher geographic latitudes, dominated in Arctic fjords (Uummannaq Fjord-Qaumarujuk Fjord). These species generally characterized coastal waters influenced by melting sea ice and/or glacial ice. Chaetoceros spp. were linked to more saline open marine waters, particularly in the Davis Strait south of 70°N, probably corresponding to weaker water stratification and the influence of the West Greenland Current. The present paper provides new knowledge on diatom assemblages along a south–north climate gradient in West Greenland, which is necessary in order to understand how observed ocean-climate changes influence Arctic marine ecosystems. This study provides a reference for palaeoenvironmental reconstructions using diatom microfossils deposited in the West Greenland marine sediments.

Diversity and distribution of foliose Bangiales (Rhodophyta) in West Greenland: a link between the North Atlantic and North Pacific

Greenland is a continental island in the northern part of the North Atlantic where the foliose Bangiales flora is poorly known. It is an important area for the study of algal biogeography because of the region’s glacial history, in which Greenland has been alternately exposed to or isolated from the North Pacific via the Bering Strait. A molecular study using 3′ rbcL + 5′ rbcL–S sequences was undertaken to assess the diversity of foliose Bangiales on the west coast of Greenland and rbcL sequences were used to study the Greenland flora in a larger phylogenetic and floristic context. New and historic collections document seven species in four genera from the west coast of Greenland. All species had a close link to North Pacific species, being either conspecific with them or North Atlantic–North Pacific vicariant counterparts.

Spatial variations of δ18O and ion species in the snowpack of the northwestern Greenland ice sheet

To determine the transport processes of water vapor and aerosols over the northwestern Greenland ice sheet, we undertook a glaciological observation at a coastal site on the northwestern part of the ice sheet and revealed spatial variations in δ 18 O and in the concentrations of chemical substances in surface snow and the snowpack. On the outlet glacier (the Meehan glacier), water vapor and sea salt were transported from the coast. On the inland ice sheet in northwestern Greenland, water vapor, mineral dust, anthropogenic substances such as NO 3 - and SO4 2- , and CH3SO3 - from marine phytoplankton were transported from the west coast of Greenland via the central part of the Greenland ice sheet. 18 O, ion species

The late Eva Clausen's collections from west and southwest Greenland 1955

Eva Clausen was a Danish botanist, known for her experimental work with the tolerance of liverworts; many of her collections that contribute to the knowledge of liverwort flora of Denmark, the Faeroes and Greenland, were donated to herbarium C after her death. One of those are collections from her trip to the west coast of Greenland in summer 1955. Only an minor part of them were worked up by Eva Clausen herself, and she never published the results of her expedition. The author of ‘The liverworts of Greenland’ (2013), Kell Damsholt has identified ca 700 specimens and examined three note books written by Eva Clausen on the trip. He found about 80 taxa of hepatics in the collections. Most of the species collected by Eva Clausen are found within their known distribution range in Greenland. Though her collections of Lophozia rubescens R. M. Schust. & Damsh. from Frederikshåb, Egedesminde and Disko Island fill in the gab in the known species distribution (the species was known only from two localities in the southernmost Greenland and one on Disko Island). The collection of Apomarsupella revoluta (Nees) R. M. Schust. at Holsteinsborg is the southernmost on the west coast of Greenland and seems promising for future records from south Greenland, from where collections are missing, probably because of too few collections from areas close to the inland ice. The record of Cephaloziella grimsulana (J. B. Jack ex Gottsche et Rabenh.)Lacout. at Disko, God-havn adds to the distribution of this rather rare, northern species in Greenland and so does the record of Cephaloziella massalongi (Spruce) Müll. Frib. at Disko, Godhavn, Blæsedalen. A female plant of Odontoschisma elongatum (Lindb.) A. Evans was found at Disko, Godhavn, for the first time from Greenland.

Warming of the Polar Water Layer in Disko Bay and Potential Impact on Jakobshavn Isbrae

Abstract A number of recent studies have shown enhanced retreat of tidewater glaciers over much of southern and western Greenland. One of the fastest retreats has occurred at Jakobshavn Isbrae, with the rapid retreat linked to the arrival of relatively warm and saline Irminger water along the west coast of Greenland. Similar links to changes in ocean water masses on the coastal shelf of Greenland were also seen on the east coast. This study presents hydrographic data from Disko Bay, additionally revealing that there was also a significant warming of the cold polar water entering Disko Bay from the mid-to-late 1990s onward. This layer, which lies at a depth of ~30–200 m, warmed by 1°–2°C. The heat content of the polar water layer increased by a factor of 3.6 for the post-1997 period compared to the period prior to 1990. The heat content in the west Greenland Irminger water layer between the same periods increased only by a factor of 2, but contained more total heat. The authors suggest that the changes in the polar water layer are related to circulation changes in Baffin Bay.

Paleoenvironments during Younger Dryas‐Early Holocene retreat of the Greenland Ice Sheet from outer Disko Trough, central west Greenland

ABSTRACTPaleoenvironments during the late Younger Dryas through early Holocene retreat of the Greenland Ice Sheet from the outer shelf in the Disko Trough system of central West Greenland were investigated via lithofacies, foraminifera, dinocysts and sediment provenance analyses in radiocarbon‐dated sediment cores from the upper slope (JR175‐VC35) and outer shelf (JR175‐VC20 and HU2008029‐070CC). Core data show that the ice margin retreated rapidly from the outer shelf by calving, beginning by 12.2k cal a BP under cold paleoceanographic conditions with up to 11 months of sea‐ice. Ice retreat into Disko Bugt was well underway by 10.9k cal a BP. Enhanced ice‐sheet ablation in Disko Bugt and elsewhere along the West Greenland coast is inferred from cold glacial marine conditions associated with high sedimentation rates between 10.9 and 9.5k cal a BP on the outer shelf. Glacial marine conditions are recorded on the outer shelf until 7.8k cal a BP. Detrital carbonate‐bearing sediments rich in >2‐mm clasts deposited between 11.6 and 10.6 k cal a BP indicate that icebergs calved from northern Baffin Bay ice margins were melting and releasing sediments along West Greenland while the Greenland Ice Sheet margin was retreating into Disko Bugt.

A net decrease in the Earth's cloud, aerosol, and surface 340 nm reflectivity during the past 33 yr (1979–2011)

Abstract. Measured upwelling radiances from Nimbus-7 SBUV (Solar Backscatter Ultraviolet) and seven NOAA SBUV/2 instruments have been used to calculate the 340 nm Lambertian equivalent reflectivity (LER) of the Earth from 1979 to 2011 after applying a common calibration. The 340 nm LER is highly correlated with cloud and aerosol cover because of the low surface reflectivity of the land and oceans (typically 2 to 6 RU, reflectivity units, where 1 RU = 0.01 = 1.0%) relative to the much higher reflectivity of clouds plus nonabsorbing aerosols (typically 10 to 90 RU). Because of the nearly constant seasonal and long-term 340 nm surface reflectivity in areas without snow and ice, the 340 nm LER can be used to estimate changes in cloud plus aerosol amount associated with seasonal and interannual variability and decadal climate change. The annual motion of the Intertropical Convergence Zone (ITCZ), episodic El Niño Southern Oscillation (ENSO), and latitude-dependent seasonal cycles are apparent in the LER time series. LER trend estimates from 5° zonal average and from 2° × 5° , latitude × longitude, time series show that there has been a global net decrease in 340 nm cloud plus aerosol reflectivity. The decrease in cos2(latitude) weighted average LER from 60° S to 60° N is 0.79 ± 0.03 RU over 33 yr, corresponding to a 3.6 ± 0.2% decrease in LER. Applying a 3.6% cloud reflectivity perturbation to the shortwave energy balance partitioning given by Trenberth et al. (2009) corresponds to an increase of 2.7 W m−2 of solar energy reaching the Earth's surface and an increase of 1.4% or 2.3 W m−2 absorbed by the surface, which is partially offset by increased longwave cooling to space. Most of the decreases in LER occur over land, with the largest decreases occurring over the US (−0.97 RU decade−1), Brazil (−0.9 RU decade−1), and central Europe (−1.35 RU decade−1). There are reflectivity increases near the west coast of Peru and Chile (0.8 ± 0.1 RU decade−1), over parts of India, China, and Indochina, and almost no change over Australia. The largest Pacific Ocean change is −2 ± 0.1 RU decade−1 over the central equatorial region associated with ENSO. There has been little observed change in LER over central Greenland, but there has been a significant decrease over a portion of the west coast of Greenland. Similar significant decreases in LER are observed over a portion of the coast of Antarctica for longitudes −160° to −60° and 80° to 150°.

Metabolic Scope and Interspecific Competition in Sculpins of Greenland Are Influenced by Increased Temperatures Due to Climate Change

Ongoing climate change has led to an increase in sea surface temperatures of 2–4°C on the west coast of Greenland. Since fish are ectothermic, metabolic rate increases with ambient temperature. This makes these animals particularly sensitive to changes in temperature; subsequently any change may influence their metabolic scope, i.e. the physiological capacity to undertake aerobically challenging activities. Any temperature increase may thus disrupt species-specific temperature adaptations, at both the molecular level as well as in behavior, and concomitant species differences in the temperature sensitivity may shift the competitive balance among coexisting species. We investigated the influence of temperature on metabolic scope and competitive ability in three species of marine sculpin that coexist in Greenland coastal waters. Since these species have different distribution ranges, we hypothesized that there should be a difference in their physiological response to temperature; hence we compared their metabolic scope at three temperatures (4, 9 and 14°C). Their competitive ability at the ambient temperature of 9°C was also tested in an attempt to link physiological capacity with behaviour. The Arctic staghorn sculpin, the species with the northernmost distribution range, had a lower metabolic scope in the higher temperature range compared to the other two species, which had similar metabolic scope at the three temperatures. The Arctic staghorn sculpin also had reduced competitive ability at 9°C and may thus already be negatively affected by the current ocean warming. Our results suggest that climate change can have effects on fish physiology and interspecific competition, which may alter the species composition of the Arctic fish fauna.

The Chatanika and Sondrestrom Radars – a brief history

Abstract. The Sondrestrom upper atmospheric research facility, located just north of the Arctic Circle near the west coast of Greenland, will soon celebrate 30 yr of operations. The centerpiece of the facility, an incoherent scatter radar, has collected 46 000 h of data on the ionospheric state parameters. This instrument was designed and built to measure the effects of nuclear bombs on radio wave propagation in the South Pacific, but instead was deployed to Alaska to study the effects of auroral structuring on the ionosphere, and was later moved to Greenland to explore the auroral cusp and the dynamics of the polar cap boundary. This is the story of the birth and genesis of the instrument, its travels, and the evolution of its facility.