Fig. 4

Filtration of representative tide gauge. Iterative filtration process to identify the representative tide gauge for the North Atlantic (NA) region in the summer season. Top: standardized RWL time series of all tide gauges within the region (left) for the common period of 1950 to 2017 and their corresponding correlation coefficient with the mean regional RWL time series (right). Bottom: same as the top panel but after removing tide gauges with correlation less than 0.6 with the regional average RWL time series; the representative tide gauge (i.e., the longest one of those retained through the filtration process) is highlighted in the bottom right panel.