13 research outputs found
ADCP-referenced geostrophic velocity and transport in the West Spitsbergen current
During the summer of 2000 and 2002 (June-July) the West Spitsbergen Current (WSC) was investigated by the Institute of Oceanology, Polish Academy of Sciences. CTD and current measurements by a vessel-mounted Acoustic Doppler Current Profiler (ADCP) were performed along three transects perpendicular to the WSC main stream and covering the region from 76°30' N to 78°20' N and from 02°30' E to 15° E. In general, the geostrophic, baroclinic flow patterns and the ADCP-measured currents were found to be in good agreement but measured current velocities were significantly higher than calculated values. This fact supports earlier observations that the barotropic component is dominant in the WSC. Since ADCP has a better spatial resolution than CTD records, the West Spitsbergen Current could be investigated and described in much greater detail than before. The main stream of Atlantic Water is topographically steered by the continental slope (isobars 800-2000 m) and the complex, multistream structure of the West Spitsbergen Current is clearly visible. The absolutely referenced total geostrophic transport is about three times higher than the estimated value assuming the level of no motion lies at 1000 m
ICES Report on Ocean Climate 2017
ICES Report on Ocean Climate (IROC) combines decades of ocean observations across the North Atlantic ICES region to describe the current status of sea temperature and salinity and atmospheric conditions, as well as observed trends and recent variability
ICES Report on Ocean Climate 2018
The Planning Group on Commercial Catch, Discards and Biological Sampling (PGCCDBS) 2012 was approached by the ICES Publications and Communications Group (PUBCOM) with the suggestion to combine the existing protocols on the age estimation of fish species within the ICES Area and publish them as an ICES Cooperative Research Report (CRR). This idea was received favourably by PGCCDBS. It was deemed important to (i) summarize the state of knowledge for key species, (ii) scrutinize, by peer review, the work done during the many calibration exercises, and, by doing so, (iii) promote an increase in quality. The aim of the present publication is to provide a comprehensive manual on the methodology of age estimation and validation and represents a collation of the state-of-the-art scientific work on the methods and validated age estimation of commercially exploited fish species across Europe. Having a collation of the latest methodologies by species grouping will also facilitate rapid and quality-assured development of methods suitable for new species
Interannual changes in zooplankton on the West Spitsbergen Shelf in relation to hydrography and their consequences for the diet of planktivorous seabirds
The purpose of the work was to determine how atmospheric and oceanic processes (the North Atlantic Oscillation (NAO) and the Arctic Ocean Oscillation (AOO)) influence hydrography and zooplankton on the West Spitsbergen Shelf (WSS), and the impacts of the processes on chick meals of zooplanktivorous little auks Alle alle. There were distinct Atlantic and Arctic oceanographic domains on the shelf resulting from the presence of the West Spitsbergen Current and the Sørkapp Current, which contain different proportions of Calanus finmarchicus and C. glacialis. The abundance of warm- and cold-water species varied as a result of an interplay between processes in the atmosphere and ocean. In the Arctic domain, on which the study focused, the NAO impacted oceanography, zooplankton, and consequently little auk chick meals, with time-lags of 4–7 years. The diet of little auk chicks was more energy-rich when C. glacialis stage 5 in the Arctic community were more easily available. To date, the changes in zooplankton abundance on the WSS have not posed a threat to the ability of little auks to feed their chicks lipid-rich Arctic copepods
Inter-annual variability of transparent exopolymer particles in the Arctic Ocean reveals high sensitivity to ecosystem changes
Sustained mass loss of the northeast Greenland ice sheet triggered by regional warming
The Greenland ice sheet has been one of the largest contributors to global sea-level rise over the past 20 years, accounting for 0.5 mm yr−1 of a total of 3.2 mm yr−1. A significant portion of this contribution is associated with the speed-up of an increased number of glaciers in southeast and northwest Greenland. Here, we show that the northeast Greenland ice stream, which extends more than 600 km into the interior of the ice sheet, is now undergoing sustained dynamic thinning, linked to regional warming, after more than a quarter of a century of stability. This sector of the Greenland ice sheet is of particular interest, because the drainage basin area covers 16% of the ice sheet (twice that of Jakobshavn Isbræ) and numerical model predictions suggest no significant mass loss for this sector, leading to an under-estimation of future global sea-level rise. The geometry of the bedrock and monotonic trend in glacier speed-up and mass loss suggests that dynamic drawdown of ice in this region will continue in the near future