Reliability of residual-based vertical land motion from altimetry–tide gauge differences: A Kalman filter diagnostic across the Korean Peninsula
Estuarine, Coastal and Shelf Science, cilt.341, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 341
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.ecss.2026.110121
- Dergi Adı: Estuarine, Coastal and Shelf Science
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Environment Index, Geobase, INSPEC, Zoological Record, Academic Search Ultimate (EBSCO)
- Anahtar Kelimeler: Coastal sea-level variability, Kalman filter, Korean Peninsula, Satellite altimetry, Tide gauges
- Yıldız Teknik Üniversitesi Adresli: Evet
Özet
The altimetry–tide gauge residual is widely used to infer vertical land motion (VLM), yet its reliability in complex coastal environments remains poorly constrained. Using 31 years of monthly observations (1993–2023) from 23 tide gauges along the Korean Peninsula, CMEMS multi-mission altimetry extracted from the nearest offshore grid cell within 5 km of each station, and GNSS-derived velocities, spatial variability in coastal sea level is analysed. Relative sea level (RSL) trends range from 1.18 to 8.23 mm/yr, substantially exceeding the spread of absolute sea level (ASL) trends (3.65–6.60 mm/yr), indicating strong local influences. To assess the validity of the residual approach, a Kalman filter–based diagnostic framework is applied at each station, and a novel Coastal Proxy Reliability Index (CPRI) is introduced to quantify its reliability. Results show that CPRI is primarily controlled by the innovation cross-correlation between tide-gauge and altimetry observations, with higher correlation indicating shared unresolved variability and reduced reliability. The method performs best under open-ocean conditions along the East Sea and fails systematically in the macro-tidal Yellow Sea, where tidal-correction errors in the gridded altimetry product and land contamination of the coastal radar footprint introduce shared, unresolved variability between tide-gauge and altimetry records, causing residual estimates to contradict GNSS-derived VLM. These findings demonstrate that the residual approach is strongly environment-dependent, and CPRI provides a practical diagnostic tool for identifying coastal settings where the residual-based VLM proxy is more likely to be reliable.