The SmartBay Observatory in Galway Bay is an important contribution by Ireland to the growing global network of real-time data capture systems deployed within the ocean. Installed on the seafloor 1.5km off the coast of Spiddal, the observatory uses cameras, probes and sensors to permit continuous and remote live underwater monitoring. Data relating to the marine environment at the site is transferred in real-time from the SmartBay Observatory through a fibre optic telecommunications cable to the Marine Institute headquarters and onwards onto the internet.

This dataset comprises of processed data that has been collected from the SmartBay Observatory site using an Idronaut Ocean-Seven 304 plus Conductivity-Temperature-Depth (CTD) sensor probe. The sensor measures the temperature and conductivity of the seawater (the conductivity is used to calculate an estimate of the salinity); the pressure exerted by the seawater above (from which the depth of the sensor is estimated); and these parameters are also used to estimate the speed of sound within the sea. CTD (Conductivity, Temperature, Depth) measures temperature, salinity, pressure in the water column. Sea temperature is a measurement of the temperature of the water as the instrument samples at a depth of 25m. Salinity is a measure of the salt content in water. The Ocean-Seven 304 Plus CTD has also been equipped with a polarographic IDRONAUT dissolved oxygen sensor which measure the dissolved oxygen concentration of the seawater. This dataset comprises of the processed data files, collected from the Galway Bay Subsea cabled observatory since its installation in 2015. The sensor is deployed on the EMSO Smartbay Cable End Equipment Node in Galway Bay in approx. 25m depth of water @ 53° 13.640'N 9° 15.979'W. Practical uses of this dataset includes but are not limited to scientists, researchers and marine technologists involved in the areas of physical oceanography. The processed dataset for CTD and dissolved Oxygen data for Galway Bay Observatory in Spiddal is located at https://erddap.marine.ie/erddap/tabledap/spiddal_obs_ctd.html The data contain the following columns: Date-time|InstrumentID| {Tab separated data columns} Date-time is a time stamp from a Global Positioning System receiver at the cable observatory shore station in the format YYYY-MM-DDThh:mm:ss.sss where: YYYY is the year MM is the month number within the year (e.g. 03 for March) DD is the day number within the month T delimits between the date and time hh is the hour within the day mm is the minute within the hour ss.sss is the second.milliseconds within the minute Z indicates the GPS timestamp is in Co-ordinated Universal Time (UTC) Instrument-ID is a unique identifier for the instrument based on its manufacturer, model number and serial number Seawater pressure in decibars Temperature of the seawater in degrees Celsius Electrical conductivity of the seawater in Siemens per metre Salinity of the seawater (salinity has no units) Sound velocity in seawater in metres per second Dissolved oxygen concentration in % Dissolved oxygen concentration in ppm The Instrument time stamp in the format hh:mm:ss.ssM Practical uses of this dataset includes but are not limited to scientists, researchers and marine technologists involved in the area of Physical Oceanography. None