PowerPointpresentasjon

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Variability of the Atlantic layer in the Lofoten
Basin
Current measurements in the northern Norwegian
Sea
Kjell Arne Mork
Kjell Arne Mork
Current measurements in the northern Norwegian
Sea
Contribution to the Bjerknes Workshop 7-8 October
2003 in Bergen.
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• Data used
• Hydrographic stations in the central Norwegian
  Sea (April-August, 1993-2002)
• Gimsøy section, 1965-2002

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Bathymetry of the Nordic Seas
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Depth of Atlantic layer (Sgt35) averaged over
1993-2002 (April-August).
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Area used for volume calculation (bottom depths
larger than 2500 m).
Volume of Atlantic Water in the Lofoten Basin
(bottom depths larger than 2500 m).
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Correlation coefficient between volume of AW and
depth of AW at each grid point. Gimsøy section
including the three western stations are marked.
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Thickness of Atlantic layer (Sgt35) in the Gimsøy
section, averaged over the three westernmost
stations. Red line is 1 year moving averages.
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Thickness of Atlantic layer, defined from three
different salinity levels
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Water mass structure and properties for two
different years.
Volume of Atlantic Water in the Lofoten Basin.
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Potential temperature and salinity in the
Gimsøy-NW section May/June 2002.
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Salinity in the Gimsøy-NW sectionfor 1999 and
2002
May/June 2002
May/June 1999
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Sigma-theta in the Gimsøy section
May/June 1999
May/June 2002
Less dense in 2002 compared to 1999
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Summary

• Depth of Atlantic layer, topographic influenced
• There has been an increase in the volume of AW
  from 1995 to 2002.
• The Gimsøy section might be used as an index for
  the volume of AW.
• Both the Atlantic and the Arctic Intermediate
  layers were thicker in 2002 compared to 1999.