EGU22-12063, updated on 05 Jan 2024
EGU General Assembly 2022
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Sub-hourly sea level quality-controlled dataset to quantify extreme sea levels along the European coasts

Marijana Balić1, Jadranka Šepić1, Leon Ćatipović1, Srđan Čupić2, Jihwan Kim3, Iva Međugorac4, Rachid Omira3, Havu Pellikka5,6, Krešimir Ruić1, Ivica Vilibić7, and Petra Zemunik8
Marijana Balić et al.
  • 1Faculty of Science, University of Split, Croatia
  • 2Hydrographic Institute of the Republic of Croatia, Croatia
  • 3Portuguese Institute of the Sea and the Atmosphere (IPMA), Portugal
  • 4Department of Geophysics, Faculty of Science, University of Zagreb, Croatia
  • 5Department of Built Environment, Aalto University, Finland
  • 6Marine Research Unit, Finnish Meteorological Institute, Finland
  • 7Ruđer Bošković Institute, Division for Marine and Environmental Research, Croatia
  • 8Institute of Oceanography and Fisheries, Croatia

Extreme sea levels can lead to floods that cause significant damage to coastal infrastructure and put people's lives in danger. These floods are a result of physical processes occurring at various time and space scales, including sub-hourly scales. To estimate the contribution of sub-hourly sea level oscillations to extreme sea levels, raw sea level data from about 300 tide gauge stations along the European coasts, with a sampling resolution of less than 20 minutes, were collected. The data were obtained from: (1) the IOC-SLSMF website (290 stations); (2) National agencies (Portugal, Finland, Croatia –24 stations). Portions of the raw dataset had various data quality issues (i.e., spikes, shifts, drifts) hence quality control procedure was required. Out of range values, values with a 50 cm difference from one neighbouring value or a 30 cm difference from both neighbouring values, were automatically removed. The automatic spike detection procedure was carried out by removing values that differed by three standard deviations from a spline fitted with the least squares method. Following the automatic quality control, all remaining data were visually examined and spurious data were removed manually.

The resulting data set contains sea level data from 2007. to 2021., with an average record length of approximately 7 years, however the length varies from a few months at some stations to 13 years at others. Tide gauges with longer records (>10 years) are based in the Baltic region, France and Spain, whereas the ones with shorter records (<3 years) are mostly based in the Eastern Mediterranean. The Western Mediterranean and western Europe have a high station coverage with records of various lengths. Tide gauges mostly provide data with a one-minute sampling frequency, however, some of them still record on a multi-minute scale (i.e., United Kingdom with 15 minutes and Norway and the Netherlands with 10 minutes sampling frequency).

Preliminary statistical analyses were done, resulting with spatial and temporal distribution of contribution of high-frequency sea level oscillations to total sea level extremes along the European coasts.

How to cite: Balić, M., Šepić, J., Ćatipović, L., Čupić, S., Kim, J., Međugorac, I., Omira, R., Pellikka, H., Ruić, K., Vilibić, I., and Zemunik, P.: Sub-hourly sea level quality-controlled dataset to quantify extreme sea levels along the European coasts, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12063,, 2022.