The United Kingdom Met Office is working in proud partnership with the Isle of Man Steam Packet Company’s vessel Ben-My-Chree. In 2017 a fully automatic weather station was installed on top of the ship between the top observation deck and the bridge, on the port side. The system weighs 6 kilograms and operates with 12 volts of electricity using a ship power source. The weather station measures atmospheric pressure (corrected to mean sea level), air temperature in the shade and relative humidity, which is the amount of water vapour in the air. 100% is saturated air, often rain or fog, and 20% would be exceptionally dry air, great for drying your washing.
The sensors comply with international meteorological standards and are highly sensitive, calibrated, traceable and serviced annually. For example, the sensors can measure air pressure and temperatures to 1 decimal place millibars / Celsius, with high confidence. The equipment is constantly monitored remotely by the Met Office and can operate as low as minus 30 Celsius or as hot as plus 70 Celsius.
The weather station sends an observation of the weather (and the ships location) as an electronic message via satellite every hour of every day, and can log the data internally if required. The ship sails in a data sparse sea area, therefore the weather observations are of the highest value to meteorologists. The data is received by the UK Met Office computers in Exeter, where quality checks are undertaken before forwarding onto all weather offices across the World. The data will feed into powerful computer models, that enable operational meteorologists to produce the shipping forecast, inshore waters reports, gale warnings and provide advice on the most efficient and safe route for the ship to sail in ever changing weather conditions.
The weather station on Ben-My-Chree is one of around 52 deployed in UK waters, totalling over 30,000 weather observations per month. The Met Office also operate hundreds of weather stations on land, as well as uses remote sensing technologies, like satellites and radar. This gives a 4-dimensional view of the current weather right now. To produce the best multi-day weather forecast requires the highest quality, density, and timeliness observational starting point, otherwise “bad data in equals bad data out”.
The UK Met Office would like to sincerely thank the Isle of Man Steam Packet Company, the Masters and crew of Ben-My-Chree and all those who kindly assist the voluntary housing and operation of the weather station.
More information is available at: www.metoffice.gov.uk and search for ‘marine observations’. This website also details our weather stations on 11 moored buoys, lightships, remote islands, 300 other cargo and cruise ships, and 1,250 drifting buoys.