Weather buoy
Encyclopedia
Weather
Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate...
and ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
data within the world's oceans, as well as aiding during emergency response to chemical spills, legal proceeding
Trial
A trial is, in the most general sense, a test, usually a test to see whether something does or does not meet a given standard.It may refer to:*Trial , the presentation of information in a formal setting, usually a court...
s, and engineering design. Moored buoy
Buoy
A buoy is a floating device that can have many different purposes. It can be anchored or allowed to drift. The word, of Old French or Middle Dutch origin, is now most commonly in UK English, although some orthoepists have traditionally prescribed the pronunciation...
s have been in used since 1951, while drifting buoys have been used since 1979. Moored buoys are connected with the ocean bottom using either chain
Chain
A chain is a sequence of connected links.Chain may also refer to:Chain may refer to:* Necklace - a jewelry which is worn around the neck* Mail , a type of armor made of interlocking chain links...
s, nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
, or buoyant polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
. With the decline of the weather ship
Weather ship
A weather ship was a ship stationed in the ocean as a platform for surface and upper air meteorological observations for use in weather forecasting. They were primarily located in the north Atlantic and north Pacific oceans, reporting via radio...
, they have taken a more primary role in measuring conditions over the open seas since the 1970s. During the 1980s and 1990s, a network of buoys in the central and eastern tropical Pacific ocean helped study the El Niño-Southern Oscillation
El Niño-Southern Oscillation
El Niño/La Niña-Southern Oscillation, or ENSO, is a quasiperiodic climate pattern that occurs across the tropical Pacific Ocean roughly every five years...
. Moored weather buoys range from 1.5 metres (4.9 ft) to 12 metres (39.4 ft) in diameter, while drifting buoys are smaller, with diameters of 30 centimetres (11.8 in) to 40 centimetres (15.7 in). Drifting buoys are the dominant form of weather buoy in sheer number, with 1250 located worldwide. Wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
data from buoys has smaller error than that from ships. There are differences in the values of sea surface temperature
Sea surface temperature
Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...
measurements between the two platforms as well, relating to the depth of the measurement and whether or not the water is heated by the ship which measures the quantity.
History
Surface weather observation
Surface weather observations are the fundamental data used for safety as well as climatological reasons to forecast weather and issue warnings worldwide. They can be taken manually, by a weather observer, by computer through the use of automated weather stations, or in a hybrid scheme using...
s at sea occurred in connection with aviation in August 1927, when Grover Loening stated that "weather stations along the ocean coupled with the development of the seaplane
Seaplane
A seaplane is a fixed-wing aircraft capable of taking off and landing on water. Seaplanes that can also take off and land on airfields are a subclass called amphibian aircraft...
to have an equally long range, would result in regular ocean flights within ten years." Starting in 1939, United States Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...
vessels were being used as weather ships to protect transatlantic air commerce. The Navy Oceanographic Meteorological Automatic Device (NOMAD) buoy's 6 metres (19.7 ft) hull was originally designed in the 1940s for the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
’s offshore data collection program. Between 1951 and 1970, a total of 21 NOMAD buoys were built and deployed at sea. Since the 1970s, weather buoy use has superseded the role of weather ships by design, as they are cheaper to operate and maintain. Drifting buoys have been used since 1979, and as of 2005, 1250 drifting buoys roamed the Earth's oceans.
Between 1985 and 1994, an extensive array of moored and drifting buoys was deployed across the equatorial Pacific Ocean designed to help monitor and predict the El Niño
El Niño-Southern Oscillation
El Niño/La Niña-Southern Oscillation, or ENSO, is a quasiperiodic climate pattern that occurs across the tropical Pacific Ocean roughly every five years...
phenomenon. Hurricane Katrina
Hurricane Katrina
Hurricane Katrina of the 2005 Atlantic hurricane season was a powerful Atlantic hurricane. It is the costliest natural disaster, as well as one of the five deadliest hurricanes, in the history of the United States. Among recorded Atlantic hurricanes, it was the sixth strongest overall...
capsized a 10 m (32.8 ft) buoy for the first time in the history of the National Data Buoy Center
National Data Buoy Center
The National Data Buoy Center is a part of the National Oceanic and Atmospheric Administration's National Weather Service...
(NDBC) on August 28, 2005. On June 13, 2006, drifting buoy 26028 ended its long-term data collection of sea surface temperature
Sea surface temperature
Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...
after transmitting for 10 years, 4 months, and 16 days, which is the longest known data collection time for any drifting buoy. The first weather buoy in the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...
was deployed by the Integrated Marine Observing System (IMOS) on March 17, 2010.
Instrumentation
Weather buoys, like other types of weather stations, measure parameters such as air temperature above the ocean surface, windWind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
speed (steady and gusting), barometric pressure, and wind direction. Since they lie in oceans and lakes, they also measure water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
temperature, wave height
Wave height
In fluid dynamics, the wave height of a surface wave is the difference between the elevations of a crest and a neighbouring trough. Wave height is a term used by mariners, as well as in coastal, ocean and naval engineering....
, and dominant wave period. Raw data is processed and can be logged on board the buoy and then transmitted via radio, cellular, or satellite communications to meteorological centers for use in weather forecasting and climate study. Both moored buoys and drifting buoys (drifting in the open ocean currents) are used. Fixed buoys measure the water temperature at a depth of 3 metres (9.8 ft). Many different drifting buoys exist around the world that vary in design and the location of reliable temperature sensors varies. These measurements are beamed to satellites for automated and immediate data distribution. Other than their use as a source of meteorological data, their data is used within research programs, emergency response to chemical spills, legal proceedings, and engineering design. Moored weather buoys can also act as a navigational aid, like other types of buoys.
Types
Weather buoys can be recognized by their yellow color and flashing yellow light at night, and range in diameter from 1.5 metres (4.9 ft) to 12 metres (39.4 ft). Those that are placed in shallow waters are smaller in size and moored using only chains, while those in deeper waters use a combination of chains, nylon, and buoyant polypropylene. Discus buoys are round and moored in deep ocean locations, with a diameter of 10 metres (32.8 ft) to 12 metres (39.4 ft). The aluminum 3 metres (10 ft) buoy is a very rugged meteorological ocean platform that has long term survivability. The expected service life of the 3 metres (10 ft) platform is in excess of 20 years and properly maintained, these buoys have not been retired due to corrosion. The NOMAD is a unique moored aluminum environmental monitoring buoy designed for deployments in extreme conditions near the coast and across the Great LakesGreat Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
. NOMADs moored off the Atlantic Canadian coast commonly experience winter storms with maximum wave heights approaching 20 metres (65.6 ft) into the Gulf of Maine.
Drifting buoys are smaller than their moored counterparts, measuring 30 centimetres (11.8 in) to 40 centimetres (15.7 in) in diameter. They are made of plastic or fiberglass, and tend to be either bi-colored, with white on one half and another color on the other half of the float, or solidly black or blue. It measures a smaller subset of meteorological variables when compared to its moored counterpart, with a barometer measuring pressure in a tube on its top. They have a thermistor (metallic thermometer) on its base, and an underwater drogue
Drogue
A drogue is a device external to the boat, attached to the stern used to slow a boat down in a storm and to keep the hull perpendicular to the waves. The boat will not speed excessively down the slope of a wave and crash into the next one nor will it broach. By slowing the vessel in heavy...
, or sea anchor, located 15 metres (49.2 ft) below the ocean surface connected with the buoy by a long, thin tether.
Deployment and maintenance
A large network of coastal buoys near the United States is maintained by the National Data Buoy Center, with deployment and maintenance performed by the United States Coast Guard. For South AfricaSouth Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, the South African Weather Service
South African Weather Service
The South African Weather Service is the meteorological service under the South African government's Department of Environmental Affairs and Tourism. SAWS is a member of the World Meteorological Organization. The agency is similar to the United States' National Weather Service.Under the South...
deploys and retrieves their own buoys, while the Meteorological Service of New Zealand performs the same task for their country. Environment Canada
Environment Canada
Environment Canada , legally incorporated as the Department of the Environment under the Department of the Environment Act Environment Canada (EC) (French: Environnement Canada), legally incorporated as the Department of the Environment under the Department of the Environment Act Environment...
operates and deploys buoys for their country. The Met Office
Met Office
The Met Office , is the United Kingdom's national weather service, and a trading fund of the Department for Business, Innovation and Skills...
in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
deploys drifting buoys across both the northern and southern Atlantic oceans.
Comparison to data from ships
Wind reports from moored buoys have smaller error than those from ships. Complicating the comparison of the two measurements are that NOMAD buoys report winds at a height of 5 metres (16.4 ft), while ships report winds from a height of 20 metres (65.6 ft) to 40 metres (131.2 ft). Sea surface temperature measured in the intake port of large ships have a warm bias of around 0.6 C-change due to the heat of the engine room. This bias has led to changes in the perception of global warmingGlobal warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
since 2000. Fixed buoys measure the water temperature at a depth of 3 metres (10 ft).