Combining physical and geochemical methods to investigate lower halocline water formation and modification along the Siberian continental slope
A series of cross-slope transects were occupied in 2013 and 2015 that extended eastward from St. Anna Trough to the Lomonosov Ridge. High-resolution physical and chemical observations collected along these transects revealed fronts in the potential temperature and the stable oxygen isotopic ratio (...
| Published in: | Ocean Science |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Copernicus Publications
2017
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| Subjects: | |
| Online Access: | https://doi.org/10.5194/os-13-983-2017 https://doaj.org/article/ca60093dc06b4d02b2acbf1d62ae7c11 |
| Summary: | A series of cross-slope transects were occupied in 2013 and 2015 that extended eastward from St. Anna Trough to the Lomonosov Ridge. High-resolution physical and chemical observations collected along these transects revealed fronts in the potential temperature and the stable oxygen isotopic ratio ( δ 18 O) that were observed north of Severnaya Zemlya (SZ). Using linear regressions, we describe mixing regimes on either side of the front that characterize a transition from a seasonal halocline to a permanent halocline. This transition describes the formation of lower halocline water (LHW) and the cold halocline layer via a mechanism that has been previously postulated by Rudels et al. (1996). Initial freshening of Atlantic Water (AW) by sea-ice meltwater occurs west of SZ, whereas higher influences of meteoric water and brine result in a transition to a separate mixing regime that alters LHW through mixing with overlying waters and shifts the characteristic temperature–salinity bend from higher (34.4 ≤ S ≤ 34.5) toward lower (34.2 ≤ S ≤ 34.3) salinities. These mixing regimes appear to have been robust since at least 2000. |
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