Indikatorbeskrivelse

1. Hovedgruppe
2. Parametere
3. Begrunnelse
4. Status
5. Lokalitet
6. Intervall
7. Metode
8. Begrensninger i metode
9. Kvalitetssikring
10. Tidsseriens lengde
11. Institusjon og kontaktpersoner
12. Tilgang til data
13. Lenker
14. Referanser

1. Hovedgruppe

2. Parametere

Water exchange through the Fram Strait.

Hydrography of the Fram Strait.

3. Begrunnelse

In the Fram Strait the water exchange is dominated by two transport regimes.

Through the Fram Strait the Arctic Ocean imports the basic quantity of the warm Atlantic waters and exports basic quantity of the cold and relatively fresh water and sea ice to the North Atlantic.

Such structure of the water and ice transport through the Fram Strait has global causes connected with the features of the atmospheric circulation in the northern hemisphere and thermohaline conditions in the Arctic and Atlantic oceans.

On the other hand even the small changes of the water, heat and salt fluxes and transport of the sea ice through the Fram Strait strongly affect on the ice conditions, thermohaline processes and water circulation in North Atlantic and all Arctic Ocean. For example, export of the fresh water has an impact on the condition of deep convection in the Greenland Sea. In the same time the deep convection is the main driving mechanism of the global oceanic circulation.

Therefore the long-term variability of the hydrography, water and sea ice transport in the Fram Strait will reflect the global climatic changes in the ocean - atmosphere system. Thus the Fram Strait is a unique place for the climatic monitoring.

4. Status

Ongoing activity. Proposed for inclusion in Miljøovervåking Svalbard og Jan Mayen.

5. Lokalitet

Most representative place to carry out monitoring of the hydrography, water exchange and sea ice transport in the Fram Strait is the section at 79N latitude.

Water transport should be measured at least in two points. The first point is in the East Greenland current and the second point in the West Shpitsbergen current. Coordinates of this points are approximately 79 00N 08 00W and 79 00N 07 00E.

6. Intervall

Hydrography on the section should be measured twice in summer (August – September) and winter (March April) every year. Distance between CTD stations should be not more than 5 miles. CTD observations should be made in the layer from surface till bottom. Water exchange and sea ice transport should be measured daily. Levels of currents observations are 75, 250, and 1000m.

7. Metode

Hydrography measurements should be carried out from research vessel using CTD sonde.

For observations of water exchange should be used two moorings with currentmeters and mini CTD. Mooring in East Greenland current should have Upper Looking Sonar for ice thickness measurements. Ice concentrations and ice velocity can daily monitor from satellite.

8. Begrensninger i metode

In winter CTD observations in the Western part of the Fram Strait can be unavailable due to hard ice conditions.
Cloudiness can be a reason of low quality of the ice satellite images.

9. Kvalitetssikring

It is necessary to carry out the calibration of all equipment according technical standards.

10. Tidsseriens lengde

Norsk Polarinstitutt has:

• Maximal length of the series of hydrography in the Fram Strait from 1959.
• Maximal length of the series of currentmeter observations in the Fram Strait from 1996.
• Maximal length of the series of the satellite observations of sea ice in the Fram Strait from 1977.

11. Institusjon og kontaktpersoner

Norsk Polarinstitutt should be responsible for monitoring in the Fram Strait.

12. Tilgang til data

Miljøovervåking Svalbard og Jan Mayen will have data which can be obtained by application.

13. Lenker

• The National Snow and Ice Data Center 
• Variability of Exchanges in the Northern Seas 

14. Referanser