Articles | Volume 7, issue 2
27 Oct 2015
 | 27 Oct 2015

Processing of water level derived from water pressure data at the Time Series Station Spiekeroog

L. Holinde, T. H. Badewien, J. A. Freund, E. V. Stanev, and O. Zielinski

Abstract. The quality of water level time series data strongly varies with periods of high- and low-quality sensor data. In this paper we are presenting the processing steps which were used to generate high-quality water level data from water pressure measured at the Time Series Station (TSS) Spiekeroog. The TSS is positioned in a tidal inlet between the islands of Spiekeroog and Langeoog in the East Frisian Wadden Sea (southern North Sea). The processing steps will cover sensor drift, outlier identification, interpolation of data gaps and quality control. A central step is the removal of outliers. For this process an absolute threshold of 0.25 m 10 min−1 was selected which still keeps the water level increase and decrease during extreme events as shown during the quality control process. A second important feature of data processing is the interpolation of gappy data which is accomplished with a high certainty of generating trustworthy data. Applying these methods a 10-year data set (December 2002–December 2012) of water level information at the TSS was processed resulting in a 7-year time series (2005–2011). Supplementary data are available at doi:10.1594/PANGAEA.843740.

Short summary
We present water level data derived from long-term measurements of water pressure at the Time Series Station Spiekeroog (southern North Sea). Problems addressed during data processing include outliers, data gaps and sensor drift. For quality control, we compared the processed data to measurements of water level obtained nearby. We also carried out a storm flood analysis and a Fourier analysis to identify major tidal components.