This work was undertaken as part of the ODaT (Ocean Data Tool) project in collaboration with Marine Scotland.

There are millions of historical observations around the UK, but relatively few studies on how they can improve our understanding of local waters.  High quality observations of physical properties have taken place for at least 60 years, so the opportunity exists to track how water properties have changed over time.  We identified the need for a region-specific data product which quantifies changes near the surface and seabed, between 1970 and present.

Historical oceanographic data around Scotland

Clearly, there are any number of ways of geographically subdividing Scottish waters, but I chose to investigate two region sets: Scottish Sea Areas and Scottish Marine Regions.  Both sets rely on region divisions which are somewhat political rather than based purely on physical oceanography, so the method of subsetting has scope for improvement.

For each region, I analysed the near-surface and near-seabed observations of oceanic data (> 5 km from coast).  A simple regression model was fitted to the data to test for temporal trend, and a cyclic component was added to assess the magnitude of seasonality.

An example of the temporal analysis for near-surface temperatures in the Orkney region

This work will be made available and hosted by the SAMS geodata server, and by Marine Scotland’s NMPI site.