Precise datum control for pressure tide gauges

Pressure tide gauges are employed at many locations around the world, and are of particular importance in environmentally hostile areas. This article describes a method for the precise datum control of sea level records from pressure tide gauges which accommodates instrumental drifts in pressure transducers and variations in the ocean itself caused by density changes. By means of an additional pressure point at approximately mean sea level, it has been found that an effective temporal discrimination of the sea level record can be used to impose a datum upon itself. The method has been tested with different pressure gauge technologies and at different locations with subcentimetric, and in most cases millimetric, accuracy results obtained. Such precise instrumentation could be of great importance to the monitoring of long‐term global sea level changes.

Keywords:

• sea level changes
• tide gauges
• pressure transducers