FRAM Service Activities

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SA Number: 1.1

Name of the SA:

FRAM-Frontiers in Arctic Marine Monitoring moorings

Institute:

Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany

Name:

Wilken-Jon von Appen

Wilken-Jon.von.Appen@awi.de

Short SA Description:

FRAM-Frontiers in Arctic Marine Monitoring moorings data dissemination

SA Description:

The data from observations of the AWI is routinely submitted to the Pangaea data publisher. In order to comply with international standards and to make the data visible to a larger audience, calibrated and quality controlled raw data has been submitted to the OceanSites GDAC. It provides ftp access to the data files in a community standardized netcdf format.

Here we primarily focus on physical measurements (water velocity, temperature, and salinity) from multiple moorings across Fram Strait. Moorings contain an anchor that sits on the ocean floor, a mooring wire that is nearly vertical in the water column, and buoyancy at the top of the mooring typically a few tens of meters below the surface in a safe distance from sea ice. Sensors can then be attached to this fixed point platform and the sensors typically record the data they measure internally. The observations have been undertaken since 1997 and are ongoing. The main objective is to monitor the Atlantic Water that flows into the Arctic Ocean and to be able to detect changes both due to interannual variability as well as climate change. Of particular interest is the volume transport and the temperature of the Atlantic Water; these parameters e.g. are an important constraint to numerical ocean models of the Arctic Ocean. While these long term data sets can be used for the assessment of trends, they can also be used for process level understanding of the oceanic dynamics in Fram Strait.

Visualisations:

Fig1_WSC_Transport.png

Fig1_WSC_Transport.png

Monthly average transport in Sverdrups (10^6 m^3/s) across the mooring array at 78°50’N in the West Spitsbergen Current. Red shows northward transport, blue shows southward transport, and green is the net.

Fig2_FS_Transport.png

Fig2_FS_Transport.png

Monthly average transport across the whole mooring array from the East Greenland shelf to Svalbard shelf. Colors as in Fig1.

Fig3_WSC_Temperature.png

Fig3_WSC_Temperature.png

Monthly and yearly average temperatures in the center of the West Spitsbergen as determined from moorings at 8°E and 7°E. The averages are taken from the surface to 350m depth. An increase in the temperature from 1997 to 2007 is seen with large variability thereafter. This record continues to 2015 as it is possible to be based on a smaller number of moorings than the transport estimates (Fig1). For various logistical reasons, not all moorings deployed in 2012 have been recovered yet.

Fig4_Deep_Water_Temperature.png

Fig4_Deep_Water_Temperature.png

Raw temperature timeseries in approximately 2500m depth from several moorings across Fram Strait. The water is comprised of two end members; one from the north (Eurasian Basin Deep Water) and one from the south (Greenland Sea Deep Water) of Fram Strait. Both of these end members have been warming (0.11+-0.02 °C/decade (GSDW) and 0.05+-0.01 °C/decade (EBDW)). At each time, an individual measurement falls in between these end members. It is expected that in 2020, they will reach the same temperature.

Fig5_Upper_Ocean_EKE.png

Fig5_Upper_Ocean_EKE.png

Mean seasonal cycle of eddy kinetic energy across Fram Strait. The mean is taken over all data from several years in January, in February, and so on. EKE, in this case at 75m depth, is a measure for how much variability there is in the ocean currents. It becomes clear that winter is more energetic than summer and that the West Spitsbergen Current (near 7°E) is more energetic than the central Fram Strait or the East Greenland Current (near 3°W). This has been attributed to the reduced stratification and increased shear in winter in the WSC.

One click links to your SA:

ftp://ftp.ifremer.fr/ifremer/oceansites/DATA/FRAM/

FRAM data located at OceanSites