Journal cover Journal topic
Ocean Science An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/os-2017-92
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
01 Dec 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Ocean Science (OS).
A comparison of data weighting methods to derive vertical land motion trends from GNSS and altimetry at tide gauge stations
Marcel Kleinherenbrink, Riccardo Riva, and Thomas Frederikse Department of Geoscience and Remote Sensing, Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands
Abstract. This study compares eight weighting techniques for Global Navigation Satellite System (GNSS)-derived Vertical Land Motion (VLM) trends at 570 tide gauge (TG) stations. The spread between the methods has a comparable size as the formal uncertainties of the GNSS trends. Taking the median of the surrounding GNSS trends shows the best agreement with differenced altimetry – tide gauge (ALT-TG) trends. An attempt is also made to improve VLM trends from ALT-TG time series. Only using highly correlated along-track altimetry and TG time series, reduces the standard deviation of ALT-TG time series up to 10 %. As a result, there are spatially coherent changes in the trends, but the reduction in the RMS of differences between ALT-TG and GNSS trends is insignificant. However, setting correlation thresholds also acts like a filter to remove problematic TG stations. This results in sets of ALT-TG VLM trends at 344–663 TG locations, depending on the correlation threshold. Compared to other studies, we decrease the RMS of differences between GNSS and ALT-TG trends (from 1.47 to 1.22 mm/yr), while we increase the number of locations (from 109 to 155), Depending on the weighting methods the mean of differences between ALT-TG and GNSS trends varies between 0.1–0.2 mm/yr. We reduce the mean of differences by taking into account the effect of elastic deformation due to present-day mass redistribution into account.

Citation: Kleinherenbrink, M., Riva, R., and Frederikse, T.: A comparison of data weighting methods to derive vertical land motion trends from GNSS and altimetry at tide gauge stations, Ocean Sci. Discuss., https://doi.org/10.5194/os-2017-92, in review, 2017.
Marcel Kleinherenbrink et al.
Marcel Kleinherenbrink et al.

Data sets

Radar Altimetry Database System (RADS)
M. Naeije, E. Schrama, and R. Scharroo
https://doi.org/10.1109/IGARSS.2000.861605
Nevada Geodetic Laboratory (NGL) MIDAS GPS trends
G. Blewitt, C. Kreemer, W. Hammond, and J. Gazeaux
https://doi.org/10.1002/2015JB012552
Permanent Service for Mean Sea Level (PSMSL)
S. Holgate, A. Matthews, P. Woodworth, L. Rickards, M. Tamisiea, E. Bradshaw, P. Foden, K. Gordon, S. Jevrejeva, and J. Pugh
https://doi.org/10.2112/JCOASTRES-D-12-00175.1
Selection of University of La Rochelle (ULR) GPS and ALT-TG trends
G. Wöppelmann and M. Marcos
https://doi.org/10.1002/2015RG000502
Marcel Kleinherenbrink et al.

Viewed

Total article views: 175 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
145 27 3 175 2 1

Views and downloads (calculated since 01 Dec 2017)

Cumulative views and downloads (calculated since 01 Dec 2017)

Viewed (geographical distribution)

Total article views: 175 (including HTML, PDF, and XML)

Thereof 175 with geography defined and 0 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 12 Dec 2017
Publications Copernicus
Download
Short summary
Tide gauges observe sea level changes, but are also affected by vertical land motion (VLM). Estimation of absolute sea level requires a correction for the local VLM. VLM motion is either estimated from GNSS observations or indirectly by subtracting tide gauge observation from satellite altimetry observations. While altimetry and GNSS observations are often not made at the tide gauge location, the estimates vary. In this study we determine the best weighting technique for both methods.
Tide gauges observe sea level changes, but are also affected by vertical land motion (VLM)....
Share