The Prediction and Research Moored Array in the Atlantic (PIRATA) is a system of

moored A mooring is any permanent structure to which a vessel may be secured. Examples include quays, wharfs, jetties, piers, anchor buoys, and mooring buoys. A ship is secured to a mooring to forestall free movement of the ship on the water. An ''an ...

observation

buoys A buoy () is a floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents. Types Navigational buoys * Race course marker buoys are used for buoy racing, the most prevalent form of yac ...

in the tropical

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

which collect

meteorological Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not ...

and

oceanographic Oceanography (), also known as oceanology and ocean science, is the scientific study of the oceans. It is an Earth science, which covers a wide range of topics, including ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics ...

data. The data collected by the PIRATA array helps scientists to better understand climatic events in the Tropical Atlantic and to improve weather forecasting and climate research worldwide. Climatic and oceanic events in the tropical Atlantic, such as the

Tropical Atlantic SST Dipole The Tropical Atlantic SST Dipole refers to a cross-equatorial sea surface temperature (SST) pattern that appears dominant on decadal timescales. It has a period of about 12 years, with the SST anomalies manifesting their most pronounced features ...

affect rainfall and climate in both

West Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Maurit ...

and

Northeast Brazil The Northeast Region of Brazil ( pt, Região Nordeste do Brasil; ) is one of the five official and political regions of the country according to the Brazilian Institute of Geography and Statistics. Of Brazil's twenty-six states, it comprises ni ...

. The northern tropical Atlantic is also a major formation area for hurricanes affecting the West Indies and the United States. Alongside the

RAMA Rama (; ), Ram, Raman or Ramar, also known as Ramachandra (; , ), is a major deity in Hinduism. He is the seventh and one of the most popular '' avatars'' of Vishnu. In Rama-centric traditions of Hinduism, he is considered the Supreme Bein ...

array in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

and the TAO/TRITON network in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

, PIRATA forms part of the worldwide system of tropical ocean observing buoys.

Partners

The project is a tripartite cooperation between

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. The principal agencies involved are

NOAA The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...

in the United States, IRD and

Météo-France Météo-France is the French national meteorological service. Organisation The organisation was established by decree in June 1993 and is a department of the Ministry of Transportation. It is headquartered in Paris but many domestic operatio ...

of France plus INPE and from Brazil.

PIRATA network

The PIRATA buoy network consists of seventeen Autonomous Temperature Line Acquisition System, or ATLAS, buoys. Twelve buoys were originally deployed in 1997. Two of these buoys were decommissioned in 1999 because of vandalism by fishing craft. Three extensions of the original network have been added. Three buoys were deployed off the coast of Brazil in 2005 and four more in 2006/2007 to extend coverage to the north and the north-east. As a demonstration exercise one buoy was deployed to the south-east of the region, off the coast of Africa, between June 2006 and June 2007. In addition to the ATLAS buoys, PIRATA has three island based meteorological stations, one at

Fernando de Noronha Fernando de Noronha () is an archipelago in the Atlantic Ocean, part of the State of Pernambuco, Brazil, and located off the Brazilian coast. It consists of 21 islands and islets, extending over an area of . Only the eponymous main island is inha ...

, another on the

Saint Peter and Saint Paul Archipelago The Saint Peter and Saint Paul Archipelago ( pt, Arquipélago de São Pedro e São Paulo ) is a group of 15 small islets and rocks in the central equatorial Atlantic Ocean.

and one on

São Tomé São Tomé is the capital and largest city of the Central African island country of São Tomé and Príncipe. Its name is Portuguese for " Saint Thomas". Founded in the 15th century, it is one of Africa's oldest colonial cities. History Álva ...

. A

tidal gauge A tide gauge is a device for measuring the change in sea level relative to a vertical datum. It its also known as mareograph, marigraph, sea-level recorder and limnimeter. When applied to freshwater continental water bodies, the instrument may ...

is also maintained at São Tomé. Dedicated hydrographic cruises and annual buoy maintenance voyages are also undertaken under the auspices of the PIRATA project.

ATLAS buoys

Each ATLAS buoy measures *wind speed and direction, *air temperature, *rainfall, *humidity, *solar radiation, *pressure, temperature and conductivity to 500 metres below sea level. In addition one buoy has an

Acoustic Doppler Current Profiler An acoustic Doppler current profiler (ADCP) is a hydroacoustic current meter similar to a sonar, used to measure water current velocities over a depth range using the Doppler effect of sound waves scattered back from particles within the water col ...

fitted alongside to measure

water current A current in a fluid is the magnitude and direction of flow within that fluid, such as a liquid or a gas. Types of fluid currents include: * Air current * Boundary current * Current (stream), a current in a river or stream * Longshore current * Oc ...

velocities Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity is a ...

and four buoys are equipped to measure net heat flux. Daily mean observations from the ATLAS buoys are received in near real time via both the

Argos System Argos is a global satellite-based system that collects, processes, and disseminates environmental data from fixed and mobile platforms around the world. The worldwide tracking and environmental monitoring system results from Franco-America ...

and Brazilian satellites. The data is processed by the TAO Project Office of

and also placed on the

Global Telecommunications System The Global Telecommunication System (GTS) is a secured communication network enabling real-time exchange of meteorological data from weather stations, satellites and numerical weather prediction centres, providing critical meteorological forecasting ...

for real time distribution to weather centres and other users. High frequency measurements are stored on the buoys and retrieved during maintenance operations. The array provides 4,000 to 4,500 unique hourly values per month.

Notable locations

One of the buoys is positioned at 0°N 0°E, where the

Equator The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...

and

Prime Meridian A prime meridian is an arbitrary meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. Together, a prime meridian and its anti-meridian (the 180th meridian in a 360°-system) form a great c ...

intersect, off the coast of Africa. This buoy is sometimes jokingly referred to as

Null Island Null Island is the point on Earth's surface at zero degrees latitude and zero degrees longitude (), i.e., where the prime meridian and the Equator intersect. Null Island is located in international waters in the Atlantic Ocean, roughly 600 km of ...

References

{{Earth-based meteorological observation Oceanographic instrumentation Physical oceanography Research projects Weather forecasting Buoyage