Journal cover Journal topic
Ocean Science An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/os-2018-59
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
31 May 2018
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Ocean Science (OS).
Better Baltic Sea wave forecasts: Improving resolution or introducing ensembles?
Torben Schmith, Jacob Woge Nielsen, and Till Andreas Soya Rasmussen Danish Meteorological Institute, Copenhagen, Denmark
Abstract. The performance of short-range operational forecasts of significant wave height in the Baltic Sea in three different configurations is evaluated. Forecasts produced by a base configuration are inter-compared with forecasts from two improved configurations: one with improved horizontal and spectral resolution and one with ensembles representing uncertainties in the physics of the forcing wind field and the initial conditions of this field. Both the improved forecast classes represent an almost equal increase in computational costs. The inter-comparison therefore addresses the question: would more computer resources most favorably be spent on enhancing the spatial and spectral resolution or, alternatively, on introducing ensembles? The inter-comparison is based on comparisons with hourly observations of significant wave height from seven observation sites in the Baltic Sea during the three-year period 2015–2017. We conclude that for most stations, the introduction of ensembles enhances the overall performance of the forecasts, whereas increasing the horizontal and spectral resolution does not. These stations represent offshore conditions, well exposed from all directions with a large distance to the nearest coast and with a large water depth. Therefore, the detailed shoreline and bathymetry is also a priori not expected to have any impact. Only for one station, we find that increasing the horizontal and spectral resolution significantly improved the forecasts. This station is situated in nearshore conditions, close to land, with a nearby island and therefore shielded from many directions. This study therefore concludes that to improve wave forecasts in offshore areas, ensembles should be introduced, while for nearshore areas better resolution may improve results.
Citation: Schmith, T., Nielsen, J. W., and Rasmussen, T. A. S.: Better Baltic Sea wave forecasts: Improving resolution or introducing ensembles?, Ocean Sci. Discuss., https://doi.org/10.5194/os-2018-59, in review, 2018.
Torben Schmith et al.
Torben Schmith et al.
Torben Schmith et al.

Viewed

Total article views: 183 (including HTML, PDF, and XML)

HTML PDF XML Total Supplement BibTeX EndNote
161 17 5 183 6 4 4

Views and downloads (calculated since 31 May 2018)

Cumulative views and downloads (calculated since 31 May 2018)

Viewed (geographical distribution)

Total article views: 183 (including HTML, PDF, and XML)

Thereof 182 with geography defined and 1 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 19 Jun 2018
Publications Copernicus
Download
Share