Multidecadal Sea Level Time Series at the Ieodo Ocean Research Station: A New Approach for the Assessment of Sea Level Rise in the East China Sea

This study presents a ten-minute interval sea level height (SLH) time series observed from wave radar MIROS SM-140 equipped at the Ieodo Ocean Research Station (I-ORS), a steel framed tower-type multidisciplinary research platform, a unique in situ measurement in the open sea for over two decades. To assess the practicability of the observed SSH, we developed a tidal model-based QC procedure, which has two notable differences in characteristics from the typical ones: 1) a spatiotemporally optimized local range check based on the high-resolution tidal prediction model TPXO9 and 2) consideration of the occurrence rate of a stuck value over a specific period. Comprehensive comparisons with typical QC processes, satellite altimetry, and reanalysis products demonstrate that our approach could provide reliable SLH time series with few misclassifications. A budget analysis demonstrated that the barystatic effect primarily caused sea level rise around the I-ORS. As a representative of sea level fluctuations in the central East China Sea, this qualified SLH time series enables dynamic research, spanning from a few hours of nonlinear waves to a decadal trend with simultaneously observed environmental variables from the I-ORS’ air–sea monitoring system.