Chapter 2: Physical Characteristics

Scottish Environment Protection Agency (SEPA) Tide Gauge Network, provide a long time series of sea level data.

This layer shows tidal gauges or river gauges below MHWS. 

Sea surface waves are mainly caused by the effects of wind on the surface of the sea. Their height is predominantly determined by the fetch (i.e. distance wind has blown over) and length of time of the wind forcing. Some local modification of wave height can be caused by tides. The seabed also influences waves in shallow water as waves will become steeper and higher as they approach the shore. Wave power is the quantification of the power transmitted by a wave moving across the sea surface. In general, larger waves are more powerful but wave power is also determined by wave speed, wavelength, and water density. Within Scottish waters, the wave climate is mainly influenced by conditions in the North Atlantic ocean, where the fetch is long enough to establish large, regular waves known as swell. The north and west of Scotland (Hebrides, Orkney and Shetland) are most exposed to these conditions. On the east coast of Scotland, conditions in autumn and winter may also be rough in the North Sea because the wind direction can lead to a large fetch. Moreover, the Moray Firth is also relatively exposed because of its shoaling bathymetry and exposure to the North Sea.

Data source: Atlas of UK Marine Renewable Energy Resources (see https://www.renewables-atlas.info/)

Annual Mean Significant Wave Height - The average height of the highest 1/3 of waves. The wave height is greatest in the Atlantic, moderate in the North Sea and least in the immediate coastal zone where the values are generally <1.2m.

Data source: Atlas of UK Marine Renewable Energy Resources (see https://www.renewables-atlas.info/)

This layer presents a 30-year (1971-2000)  salinity climatology for near-bed regions of the NW European shelf seas, with a resolution of 1/6 longitude by 1/10 latitude. The data have been extracted from the International Council for the Exploration of the Sea (ICES) data centre and supplemented by additional records from the World Ocean Data Centre (WODC). From the original data, which are irregularly distributed in space and time, the mean monthly temperature and salinity are calculated, as well as the climatic mean annual cycle. The climatology presented here is an improvement upon all existing climatologies presented in the literature for the NW European shelf; covering a wider area on a finer scale and including the surface and near-bed distribution of both temperature and salinity. Comparison of our data with existing climatologies shows good agreement, with differences occurring where our climatology is an improvement. This climatology, which will prove to be valuable to many users in the marine community will be regularly updated and made available to all users via the ICES data centre.