Journal cover Journal topic
Ocean Science An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 2.289 IF 2.289
  • IF 5-year value: 2.756 IF 5-year 2.756
  • CiteScore value: 2.76 CiteScore 2.76
  • SNIP value: 1.050 SNIP 1.050
  • SJR value: 1.554 SJR 1.554
  • IPP value: 2.65 IPP 2.65
  • h5-index value: 30 h5-index 30
  • Scimago H index value: 41 Scimago H index 41
Discussion papers
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 03 Sep 2018

Research article | 03 Sep 2018

Review status
This discussion paper is a preprint. A revision of the manuscript is under review for the journal Ocean Science (OS).

Multidecadal variability in seasonal mean sea level along the North Sea coast

Thomas Frederikse1 and Theo Gerkema2 Thomas Frederikse and Theo Gerkema
  • 1Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, USA
  • 2NIOZ Netherlands Institute for Sea Research, Department for Estuarine and Delta Systems (EDS), and Utrecht University, PO Box 140, 4400 AC Yerseke, The Netherlands

Abstract. Seasonal deviations from annual-mean sea level in the North Sea region show a large low-frequency component with substantial variability at decadal and multi-decadal time scales. In this study, we quantify low-frequency seasonal variations from annual-mean sea level and look for drivers of this variability. The amplitude, as well as the temporal evolution of this multi-decadal variability shows substantial variations over the North Sea region, and this spatial pattern is similar to the well-known pattern of the influence of winds and pressure changes on sea level on higher frequencies. The largest low-frequency signals are found in the German Bight and along the Norwegian coast. We find that the variability is much stronger in winter and autumn than in other seasons, and that this winter and autumn variability is predominantly driven by wind and sea-level pressure anomalies which have their cause in large-scale atmospheric patterns. For the spring and summer seasons, only a small fraction of the observed variability can be explained by local and large-scale atmospheric changes.

Large-scale atmospheric patterns have been derived from a principal component analysis of sea-level pressure. The first principal component of sea-level pressure over the North Atlantic Ocean, which is linked to the North Atlantic Oscillation (NAO), explains the largest fraction of winter-mean variability for most stations, while for some stations, the variability consists of a combination of multiple principal components.

The low-frequency variability in season-mean sea level can manifest itself as trends in short records of seasonal sea level. For multiple stations around the North Sea, running-mean 40-year trends for autumn and winter sea level often exceed the long-term trends in annual mean sea level, while for spring and summer, the seasonal trends have a similar order of magnitude as the annual-mean trends. Removing the variability explained by atmospheric variability vastly reduces the seasonal trends, especially in winter and autumn.

Thomas Frederikse and Theo Gerkema
Interactive discussion
Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for Authors/Topic Editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Thomas Frederikse and Theo Gerkema
Thomas Frederikse and Theo Gerkema
Total article views: 406 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
331 63 12 406 11 15
  • HTML: 331
  • PDF: 63
  • XML: 12
  • Total: 406
  • BibTeX: 11
  • EndNote: 15
Views and downloads (calculated since 03 Sep 2018)
Cumulative views and downloads (calculated since 03 Sep 2018)
Viewed (geographical distribution)
Total article views: 406 (including HTML, PDF, and XML) Thereof 404 with geography defined and 2 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 15 Nov 2018
Publications Copernicus