The Copernicus Marine Service Ocean State Report, Issue 4 (open access) has been published in Journal of Operational Oceanography with following contributions of our colleagues from the department Hydrodynamics and Data Assimilation. For further information please contact Dr Joanna Staneva and Marcel Ricker, authors of the publications:
Staneva, J., Behrens, A., & Gayer, G. (2020): Predictability of large wave heights in the western Black Sea during the 2018 winter storms. In: Schuckmann, K., et al. (eds): Copernicus Marine Service Ocean State Report, Issue 4, Journal of Operational Oceanography, Volume 13 Supplement, Section 4.7, doi:10.1080/1755876X.2020.1785097
Statement of main outcome:
Over the past decade, European seas have been afflicted by severe storms, which caused serious damages in offshore and coastal zones. Severe storms hit the western Black Sea at the beginning of 2018. Wave conditions in the western Black Sea during the storms were high in winter 2018 and the maximum value of the significant wave height reached more than 7 m. Making use of the annual time scale provides enough samples to examine quantiles even higher than the 99th percentile supporting the understanding of the peak values in the western part of the Black Sea. The predictability of the expected largest wave heights during the winter marine storms in 2018 is demonstrated. Close match of the Black Sea CMEMS data with the satellite measurements for high waves is observed. We evaluated the extreme wave conditions in the Black Sea in 2018, based on satellite and model data, when several strong storms have been identified, considering maximum significant wave heights over a given threshold (e.g. 6 events with significant wave height >5 m in the western Black Sea).
Ricker, M., Stanev, E.V., Badewien, T.H., Freund, H., Meyerjürgens, J., Wolff, J.-O., & Zielinski, O. (2020): Drifter observations and Lagrangian tracking of the 2018 easterly wind event in the North Sea. In: Schuckmann, K., et al. (eds): Copernicus Marine Service Ocean State Report, Issue 4, Journal of Operational Oceanography, Volume 13 Supplement, Section 4.9, doi:10.1080/1755876X.2020.1785097
Statement of main outcome:
Persistent easterly winds in spring 2018 reversed the circulation in the North Sea for more than a month. This reversal has been documented by GPS-drifter observations, as well as by the stranding positions of wooden drifters released along the German North Sea coast. The latter information came from members of the public, the majority of which are likely to be non-scientists. It provided a valuable contribution to the GPS-drifter experiment and demonstrates an excellent example of the usefulness of citizen science. Lagrangian numerical experiments were also performed and helped explain and quantify the anomalous transport and the reversal of the circulation at the sea surface and in deeper layers. It has been shown that the CMEMS surface current products agree well with drifter observations, even under extreme wind conditions, which adds to their credibility.