4268 20190909101519.0 10.1175/JTECH-D-18-0235.1 DOI SCART-2019-0193 Gobron, K. Assessment of tide gauges biases and precisions by the combination of multiple co-located time series 2019 This study proposes a method for the cross-calibration of tide gauges. Based on the combination of at least three co-located sea level time series, it takes advantage of the Least-Squares Variance Component Estimation method to assess both sea-level biases and uncertainties in real conditions. The method was applied to a multi-instrument experiment carried out on Aix island, France, in 2016. Six tide gauges were deployed to carry out simultaneous sea level recordings for 11 hours. The best results were obtained with an electrical contact probe, which reaches a 3-millimeter uncertainty. The method allows assessing both the biases and the precision – i.e., the full accuracy – for each instrument. The results obtained with the proposed combination method have been compared to that of a buddy-checking method. It showed that the combination of all time series also provides more precise bias estimates. U. La Rochelle and DGA-France/ U. La Rochelle and DGA-France/ U. La Rochelle and DGA-France NO Cross-calibration of tide gauges Aix island (France) Least-Squares Variance Component Estimation method Sea-level biases and uncertaintie de Viron, O. Wöppelmann, G. Poirier, E. Ballu, V. Van Camp, M. Journal of Atmospheric and Oceanic Technology 2019 michel.vancamp@observatoire.be https://doi.org/10.1175/JTECH-D-18-0235.1 published in REFERD