The Environmental Monitoring Division participates in the international marine program and specifically the systems for marine and ocean observation and data collection project. With the support of the Canadian Coast Guard/Fisheries and Oceans Canada, the division maintains a network of nine moored ODAS (Offshore Data Acquisition Systems) buoys along the coasts of Newfoundland and Nova Scotia. The buoys collect and transmit hourly weather and sea state data 24 hours a day, seven days a week. Data is transmitted to the GOES satellite then relayed to earth stations where it is entered into the Global Telecommunications System (GTS). Archiving of data is done by the Marine Environmental Data Service (MEDS) of the Department of Fisheries and Oceans and by Environment Canada.
These data are used in the production of marine forecasts, as input into numerical weather prediction models for marine forecast guidance and to provide data in a data sparse area particularly valuable during the hurricane season. The buoys also provide data for climatological records which are used in many research projects and applications such as design wave climates for offshore construction.
A NOMAD Weather Buoy
The NOMAD buoy (see picture above) measures 6 metres by 3 metres and weighs 8 tons. It has a ship-shaped hull designed to withstand severe weather. There are two masts on which are mounted radar reflectors, a navigational lamp, solar panels and an array of meteorological sensors. A smaller 3 metre discus-shaped buoy (referred to as a 3-D buoy) is used for inland waters and near shore deployments. The "A" frame on this buoy holds the same array of instruments as the NOMAD buoy.
|
The buoys are moored in water depths up to 4500 metres using a combination of rope and chain moorings. Buoys are visited once a year by MSC marine data technicians for on site maintenance.
|
Chains used to moor the buoys
|
Every 3 to 4 years, the buoys are exchanged and returned to shore for painting and refurbishing. Unscheduled trips are occasionally made to retrieve buoys that have become de-moored through fishing activity, vandalism or hardware failure. Onboard GPS and satellite transmitters allow for tracking and recovery of the buoys by the Canadian Coast Guard in the event of a failed mooring.
The Environmental Monitoring Division, in cooperation with the US and British authorities, also participates in the drifting buoy program. Small buoys are released from vessels or dropped from aircraft in data sparse regions of the oceans and are left to drift with the ocean currents. These buoys transmit their location, sea surface temperature, air temperature and barometric pressure. Data enters the GTS in the same manner as the moored buoys. The data from the drifting buoy program are especially useful in tracking large storms. MEDS is the global center for archiving the drifting buoy data.
Waverider Buoy
The Environmental Monitoring Division is also responsible for the Osborne Head waverider buoy, moored near the mouth of Halifax Harbour. The buoy measures wave data that is transmitted to a shore station. Every 3 hours, reports of wave height and period are generated from these data and the reports are used in the production of the Halifax Harbour forecast in support of shipping operations in the harbour and for the safety of small craft. The local surfing community also has an interest in this data.
|
