67 research outputs found
Estimation of glacial meltwater discharge into Svalbard coastal waters. Oceanologia 39
Abstract During the summer expeditions of r/v 'Oceania' in 1995'Oceania' in -1996, oceanographic investigations comprising CTD profiling and suspension measurements were conducted in Svalbard fjords and shelf waters. The freshwater volume was estimated independently from the salinity drop as compared with the assumed background salinity and from the distribution of mineral suspension density in surface waters. Preliminary calculations of the instantaneous freshwater volume based on the distribution of suspended matter (at depths of < 150 m) yielded a figure of 80 km 3 in Svalbard coastal waters in summer. Values for Hornsund and Kongsfjord ranged from 0.4 to 0.7 km 3 of freshwater at the height of summer. This corresponds well with glaciological estimations, which give an annual discharge of 14.6 to 27.5 km 3 of freshwater for Svalbard. The glacial discharge is estimated to make up some 42% of the freshwater budget of Svalbard shelf waters, the remainder being derived from Barents Sea Arctic waters of reduced salinity
Postglacial expansion of the arctic keystone copepod calanus glacialis
Calanus glacialis, a major contributor to zooplankton biomass in the Arctic shelf seas, is a key link between primary production and higher trophic levels that may be sensitive to climate warming. The aim of this study was to explore genetic variation in contemporary populations of this species to infer possible changes during the Quaternary period, and to assess its population structure in both space and time. Calanus glacialis was sampled in the fjords of Spitsbergen (Hornsund and Kongsfjorden) in 2003, 2004, 2006, 2009 and 2012. The sequence of a mitochondrial marker, belonging to the ND5 gene, selected for the study was 1249 base pairs long and distinguished 75 unique haplotypes among 140 individuals that formed three main clades. There was no detectable pattern in the distribution of haplotypes by geographic distance or over time. Interestingly, a Bayesian skyline plot suggested that a 1000-fold increase in population size occurred approximately 10,000 years before present, suggesting a species expansion after the Last Glacial Maximum.GAME from the National Science Centre, the Polish Ministry of Science and Higher Education Iuventus Plus [IP2014 050573]; FCT-PT [CCMAR/Multi/04326/2013]; [2011/03/B/NZ8/02876
Responses in Arctic marine carbon cycle processes: conceptual scenarios & implications for ecosystem.
The Arctic Ocean is one of the fastest changing oceans, plays an important role in global carbon cycling and yet is a particularly challenging ocean to study. Hence, observations tend to be relatively sparse in both space and time. How the Arctic functions, geophysically, but also ecologically, can have significant consequences for the internal cycling of carbon, and subsequently influence carbon export, atmospheric CO2 uptake and food chain productivity. Here we assess the major carbon pools and associated processes, specifically summarizing the current knowledge of each of these processes in terms of data availability and ranges of rates and values for four geophysical Arctic Ocean domains originally described by Carmack & Wassmann (2006): inflow shelves, which are Pacific-influenced and Atlantic-influenced; interior, river-influenced shelves; and central basins. We attempt to bring together knowledge of the carbon cycle with the ecosystem within each of these different geophysical settings, in order to provide specialist information in a holistic context. We assess the current state of models and how they can be improved and/or used to provide assessments of the current and future functioning when observational data are limited or sparse. In doing so, we highlight potential links in the physical oceanographic regime, primary production and the flow of carbon within the ecosystem that will change in the future. Finally, we are able to highlight priority areas for research, taking a holistic pan-Arctic approach
Remote and local monitoring of dissolved and suspended fluorescent organic matter off the Svalbard
Distribution maps of CDOM and algal pigments, both in superficial and deep waters, have been obtained operating a portable dual laser spectrofluorometer and a lidar fluorosensor equipments for the first time during two polish AREX oceanographic campaigns in 2006 and 2007 summertime in the Svalbard area. The different hydrological regimes strongly affected the biological factors in the waters around the Svalbard Islands as monitored during the campaigns with strong regional differentiations between the two years. The occurrence of large phytoplanktonic blooms and patches have been observed in the western area of the Spitsbergen Island coastline due to the nutrient release from pack ice and/or iceberg melting with values of more than 10 µg/l in both campaigns. Different CDOM fractions have been monitored with the remote and local instruments and inverse proportionality with salinity is confirmed along the water column. Phycobilin pigments, as phycoerythrin and phycocyanin accessory algal pigments, have been monitored in the northern area as well as tyrosine and tryptophan protein-like fluorescence distribution. The double filtration, performed with the dual laser spectrofluorometer, allows to retrieve the small fluorescence contribution due to NADPH and carotenoids pigments in the blue fluorescence emission. Successively, the large spectroscopic data base has been critically analyzed with a robust statistic instrument, thus identifying different marine provinces and retrieve distinctive CDOM fractions
Duration of female parental care and their survival in the little auk Alle alle - are these two traits linked?
Desertion of offspring before its independence by one of the parents is observed in a number of avian species with bi-parental care but reasons for this strategy are not fully understood. This behaviour is particularly intriguing in species where bi-parental care is crucial to raise the brood successfully. Here, we focus on the little auk, Alle alle, a small seabird with intensive bi-parental care, where the female deserts the brood at the end of the chick rearing period. The little auk example is interesting as most hypotheses to explain desertion of the brood by females (e.g. “re-mating hypothesis”, “body condition hypothesis”) have been rejected for this species. Here, we analysed a possible relationship between the duration of female parental care over the chick and her chances to survive to the next breeding season. We performed the study in two breeding colonies on Spitsbergen with different foraging conditions – more favourable in Hornsund and less favourable in Magdalenefjorden. We predicted that in Hornsund females would stay for shorter periods of time with the brood and would have higher survival rates in comparison with birds from Magdalenefjorden. We found that indeed in less favourable conditions of Magdalenefjorden, females stay longer with the brood than in the more favourable conditions of Hornsund. Moreover, female survival was negatively affected by the length of stay in the brood. Nevertheless, duration of female parental care over the chick was not related to their parental efforts, earlier in the chick rearing period, and survival of males and females was similar. Thus, although females brood desertion and winter survival are linked, the relationship is not straightforward
On large-scale shifts in the Arctic Ocean and sea-ice conditions during 1979-98
Results from a regional model of the Arctic Ocean and sea ice forced with
realistic atmospheric data are analyzed to understand recent climate variability in the
region. The primary simulation uses daily-averaged 1979 atmospheric fields repeated for
20 years and then continues with interannual forcing derived from the European Centre
for Medium-range Weather Forecasts for 1979-98. An eastward shift in the ice-ocean circulation,
fresh-water distribution and Atlantic Water extent has been determined by comparing
conditions between the early 1980s and 1990s. A new trend is modeled in the late 1990s,
and has a tendency to return the large-scale sea-ice and upper ocean conditions to their state
in the early 1980s. Both the sea-ice and the upper ocean circulation as well as fresh-water
export from the Russian shelves and Atlantic Water recirculation within the Eurasian Basin
indicate that the Arctic climate is undergoing another shift. This suggests an oscillatory
behavior of the Arctic Ocean system. Interannual atmospheric variability appears to be
the main and sufficient driver of simulated changes. The ice cover acts as an effective dynamic
medium for vorticity transfer from the atmosphere into the ocean
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