A study of ten tide gauge records from the Clyde in Western Scotland

Sea level information, and its understanding, are essential for research in oceanography and coastal engineering. This paper describes sea level variability in the Clyde using data from 10 tide gauges. High coherence of sea level variability is found between the Firth of Clyde and estuary of the River Clyde, and between the Firth and estuary and the upstream part of the river. Consequently, if gaps exist in any of the records, missing information can be inferred from others. This applies to timescales of typically hours and longer, appropriate for storm surge or mean sea level change studies. No evidence exists for ‘see-saw’ oscillations of the river on subtidal timescales, as reported for the River Thames, but higher-frequency variability (typical period 45 minutes) is found with equal, or opposite, phase at different river locations. Such a standing wave behaviour would be one of the few reported examples of ‘river seiches’. Data from several agencies are used: two gauges of the UK National Network of the Environment Agency, five from the Scottish Environment Protection Agency, and three from Peel Ports. Only the former tend to be used in academic studies, but the present paper has demonstrated how useful complementary sources can be.