The salinity: δ¹⁸O water relationship in Kongsfjorden, western Spitsbergen

Abstract

We present the first oxygen isotope measurements from Kongsfjorden in north-west Spitsbergen, and use the isotopic composition and hydrographic data to provide a detailed assessment of the mixing between freshwater and oceanic waters. Temperature, salinity(s) and oxygen isotope profiles are used to describe the seasonal evolution of hydrography in the inner part of the fjord, and to infer the dominant mixing and exchange processes. Data from atmospheric, glacial and marine sources throughout Kongsfjorden are used to construct a salinity: δ¹⁸O mixing line in a region that receives inputs of freshwater and marine Atlantic water. The dominant source of freshwater is glacial melt from a tidewater glacier complex at the head of the fjord, resulting in a seawater salinity: δ¹⁸O relationship where δ¹⁸O =0.43S - 14.65. The Kongsfjorden data provides a northern latitudinal limit for mixing lines in the northwestern European coastal system.