NACO - Project description

2. Scientific and technological environment

The two-branch Norwegian Atlantic Current (NwAC) through the Norwegian Sea serves as a conduit of warm and saline water from the North Atlantic to the Arctic Ocean. A change of this transport may cause dramatic climatic-related changes, such as reduction of the Arctic sea ice cover and ecological disruptions. Quantifying and understanding the variability of the transport within and between these regions is thus important for our understanding of the climate system, both in Northern Europe and the Arctic. The NwAC is currently monitored at three locations, the Fram Strait inflow to the Arctic Ocean, Barents Sea inflow and the Svinøy section (SS) in the south (Figure 1). Ocean carbon parameters and deep sea variability below the Atlantic Water and down to the seafloor is monitored at station M (66N, 2E) via the project PolarBuoy led by the Institute of Marine Research in combination with occasional research vessel visits continuing ocean time series from the ship Polarfront that operated until December 2009.

Figure 1. Map with sea surface temperature.
(K.A.Orvik and P.Niiler, 2002. Major pathways of Atlantic water in the northern North Atlantic and Nordic Seas toward Arctic. Geophysical Research Letters, Vol.29,NO.19, 1896, doi:10.1029/2002GL015002.)

Current measurements in the eastern branch of the NwAC were initiated in 1995 at the Svinøy section, to date resulting in a unique 15 year time series of volume and heat fluxes based on an array of moored conventional current meters. The applicability of the Svinøy section as a prediction area of downstream events has been demonstrated concerning the warming of the Arctic as well as the minimum ice cover in 2006 that coincided with an extreme heat inflow in the Svinøy section.

Regular measurements of hydrography (temperature, salinity, oxygen) were initiated at station M in 1948, later extended by more parameters including a full suite of high precision ocean carbon measurements. The highest precision measurements are based on water sampling using winch from the ship and transport of water samples to laboratory onshore for analysis. Some of these time series are continued by the PolarBuoy and by visits with research vessels from the Institute of Marine Research and University of Bergen. [The ship Polarfront ( also provided a platform for air-sea exchange studies and various campaigns in addition to the regular monitoring program which included a considerable atmospheric monitoring program including carbon and methane isotopic characterization by international collaborators. These measurements have now been discontinued.]

Recent studies have revealed the Lofoten basin (LB) as a crucial area for water transformation and heat loss toward the Arctic e.g. through eddies. It is still not understood how and why the Lofoten basin fills up with Atlantic water. Accordingly a substantial part of the Svinøy section transport does not follow the continental slope northward, but is lost in dynamic eddy activity, especially off Lofoten-Vesterålen. The dynamic eddy activity also adds to the heat loss of the NwAC, and thus affects the flux of volume, heat, carbon, biological matter and pollution into the Arctic.

The main scientific challenge for observational infrastructure in this area is to transcend from the traditional, homogeneous, long term but single point time series of different parameters to a unified, modern, efficient and strategic sampling scheme which provides continuity in time but also spatial coverage in a representative way for the scientific users.

Ocean research has been technology driven for many decades (National Academy of Science, US, Millennium Report, 2000) in the sense that availability and application of new technology has led to major steps of progress in discovery and understanding. E.g. observations of water column physics and biology by acoustic technology has strongly improved current measurements and revolutionized the space-time description of biological material including fish species. Argo drifters which are now populating the world oceans with more than 3000 floats are a great success for describing variability of temperature and salinity in the upper 2000m and are beginning to also give reliable oxygen measurements. Cable based ocean observatories are being implemented for special purposes such as earth quake and tsunami detection (Japan) and multidisciplinary process studies (Canada, US, beginning also in Europe). Satellite remote sensing is revolutionizing the availability of surface observations with high spatial and temporal coverage.

The longest time series are from point measurements and their quality is enhanced by the homogeneity over time in sampling schemes and procedures. However, the cost of operating ships for such measurements is considerable, and it is a requirement for frontier research in this area to move towards automated observations with wider coverage and near real time data delivery, preferably also interactive control of the sampling scheme. While Argo floats can provide fully automated data from many areas of the global ocean, several of the crucial areas including boundary currents along continental slopes which serve as conduits for major mass and heat flows in the ocean require more active sampling schemes provided so far only by ships but with great potential for gliders.

Gliders have been in the development phase for several decades and have achieved major breakthroughs recently with longer endurance for single missions (record of 9 months set in 2009) and rapidly expanding user base globally. The operation and "flight control" of gliders is a research task normally performed by teams of scientists and engineers at universities and research institutions. The field is developing rapidly with emerging groups such as EGO (Everyones Glider Observatories), contributing to software, data handling, competence building and exchange of expertise.

The OceanObs conference in Venice in September 2009 provided multi-authored up-to-date reviews of available ocean observation technologies and also evaluations of the potential for each of these to develop into more automated use for real-time applications beyond research. These reviews confirm the appropriateness and value of a glider observatory in the chosen region. A subsequent more detailed survey of the development and operation of similar glider observatories in other countries including Australia has provided basis for the specifications of the observatory presented in the present document.

The project is highly relevant to the two first stated priorities in the plan i.e. Energy and environment (including climate) and Ocean research where the need for ships and related facilities has been mentioned in particular. Norway is a recognized leading nation in ocean observations, however biased towards ship-based measurements and so far with limited activities within either autonomous, cable-based or wireless observations. The present infrastructure aims to build upon but transcend the limitations of ship based and moored instrumentation in creating an observatory for the future.

Our ambition is to continue and improve the monitoring from the Svinøy section northward in the Norwegian Sea, exploiting and continuing measurements as well as developing new infrastructure to help clarify unsolved queries about the Atlantic water transport through the Nordic Seas towards the Arctic.

Since the existing multiparameter time series from the area as a whole (SS via M to LB) are not yet long enough to distinguish possible climate change from variability, it is a national responsibility to maintain and extend infrastructure in the area as a reference for climate changes and prediction of climate variability downstream in the Norwegian Sea, Barents Sea and the Arctic Ocean. The ocean carbon measurements today require ship based sampling. The development of a capability to combine with physical measurements on moving platforms is challenging and will have to be based upon technology development in other projects. It is considered by most investigators internationally that automated high precision carbon measurements will evolve from the presently dominating labor-intensive ship based measurements via automated ship board and moored instruments (like PolarBuoy). For moving platforms there presently exist sensors to measure only parameters which have some relation to ocean carbon, but does not measure carbon directly. Such sensors can be exploited with a view towards future expansion as the capabilities develop.

Infrastructure will contribute to collaboration already established in networks such as ASOF ( and furthered though projects such as iAOOS ( and DAMOCLES (, which are International Polar Year projects, as well as CARBOOCEAN ( It builds upon insights also from surface drifter projects, most recently through Poleward ( It will complement the project PolarBuoy (led by the Institute of Marine Research and funded by the Research Council of Norway from 2009) which will continue some time series at station M, but will not have spatial coverage in the wider area. The measurements proposed in connection with PolarBuoy at the location will be useful and complementary to the measurements proposed here. The reference current meter moorings contained in the present proposal are needed since we need such data located on the continental slope and cover shallower water for continuation of the Svinøy section time series and for easy and good combination with glider observations.

Station M is included in the EU project Eurosites ( and in OceanSites (, a world-wide system of deepwater reference systems designed to take the pulse of the world oceans. These links testify to the high recognition and importance of the existing time series and suggests a very wide interest in continued and augmented observations.

While activities in the above mentioned research projects have a finite lifetime, new research project opportunities are expected to emerge through existing research funding mechanisms. Long term funded research activities for which the infrastructure will be highly relevant are the Bjerknes Centre for Climate Research and the newly established ICE centre at the Norwegian Polar Institute ( In addition to individual research projects and long-term funded research centres, operational monitoring and forecasting is developing in Europe through highly prioritized projects such as MyOcean. Links from NACO to operational oceanography will be furthered through the Arctic Regional Ocean Observing System (Arctic ROOS, where the Geophysical Institute is a contributing member.

Government and research council strategies for the high North both point to environmental concerns and marine issues as key to sustainable development. NACO will underpin specific research projects in several disciplines as well as operational services for the northern areas. When the BarentsWatch initiative ( ressurser/barentswatch.html?id=546594) moves from the i-Nord pre-project that was finished in 2009 to development of an operational system, the observations to be delivered from the present proposed infrastructure may provide a backbone for the operational modelling services to be established for the Barents Sea and the high North. We therefore believe that an augmented user base consisting of individual science projects, long term research activities as well as more applied users will be able to fund running and upgrading expenses when a proven technology has been demonstrated through the lifetime of the present project.