Global Ocean Data Analysis Project
Encyclopedia
The Global Ocean Data Analysis Project (GLODAP) is a synthesis project bringing together oceanographic
data collected during the 1990s by research cruises on the World Ocean Circulation Experiment
(WOCE), Joint Global Ocean Flux Study (JGOFS) and Ocean-Atmosphere Exchange Study (OACES) programmes. The central goal of GLODAP is to generate a global climatology
of the World Ocean
's carbon cycle
for use in studies of both its natural and anthropogenically-forced
states. GLODAP is funded by the National Oceanic and Atmospheric Administration
(NOAA), the U.S. Department of Energy
(DOE), and the National Science Foundation
(NSF).
(DIC), alkalinity
, carbon-14
(14C), CFC-11 and CFC-12. The fields consist of three-dimensional
, objectively
-analysed global
grids at 1°
horizontal resolution, interpolated
onto 33 standardised vertical intervals from the surface (0 m) to the seafloor
(5500 m). In terms of temporal
resolution, the relative scarcity of the source data mean that, unlike the World Ocean Atlas
, averaged fields are only produced for the annual time-scale. The GLODAP climatology is missing data in certain oceanic provinces including the Arctic Ocean
, the Caribbean Sea
, the Mediterranean Sea
and the Malay Archipelago
.
Additionally, analysis has attempted to separate natural from anthropogenic DIC, to produce fields of pre-industrial
(18th century) DIC and "present day" anthropogenic CO2. This separation allows estimation of the magnitude of the ocean sink
for anthropogenic CO2, and is important for studies of phenomena such as ocean acidification
. However, as anthropogenic DIC is chemically and physically identical to natural DIC, this separation is difficult. GLODAP used a mathematical technique known as C* (C-star) to deconvolute
anthropogenic from natural DIC (there are a number of alternative methods). This uses information about ocean biogeochemistry
and CO2 surface disequilibium together with other ocean tracers including carbon-14, CFC-11 and CFC-12 (which indicate water mass
age) to try to separate out natural CO2 from that added during the ongoing anthropogenic transient. The technique is not straightforward and has associated errors, although it is gradually being refined to improve it. Its findings are generally supported by independent predictions made by dynamic models.
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...
data collected during the 1990s by research cruises on the World Ocean Circulation Experiment
World Ocean Circulation Experiment
The World Ocean Circulation Experiment was a component of the international World Climate Research Program, and aimed to establish the role of the World Ocean in the Earth's climate system...
(WOCE), Joint Global Ocean Flux Study (JGOFS) and Ocean-Atmosphere Exchange Study (OACES) programmes. The central goal of GLODAP is to generate a global climatology
Climatology
Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time, and is a branch of the atmospheric sciences...
of the World Ocean
World Ocean
The World Ocean, world ocean, or global ocean, is the interconnected system of the Earth's oceanic waters, and comprises the bulk of the hydrosphere, covering almost 71% of the Earth's surface, with a total volume of 1.332 billion cubic kilometres.The unity and continuity of the World Ocean, with...
's carbon cycle
Carbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth...
for use in studies of both its natural and anthropogenically-forced
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
states. GLODAP is funded by the National Oceanic and Atmospheric Administration
National Oceanic and Atmospheric Administration
The National Oceanic and Atmospheric Administration , pronounced , like "noah", is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere...
(NOAA), the U.S. Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
(DOE), and the National Science Foundation
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
(NSF).
Dataset
The GLODAP climatology contains analysed fields of "present day" (1990s) dissolved inorganic carbonTotal inorganic carbon
The total inorganic carbon or dissolved inorganic carbon is the sum of inorganic carbon species in a solution. The inorganic carbon species include carbon dioxide, carbonic acid, bicarbonate anion, and carbonate. It is customary to express carbon dioxide and carbonic acid simultaneously as CO2*...
(DIC), alkalinity
Alkalinity
Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...
, carbon-14
Carbon-14
Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon with a nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues , to date archaeological, geological, and hydrogeological...
(14C), CFC-11 and CFC-12. The fields consist of three-dimensional
Three-dimensional space
Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...
, objectively
Objectivity (science)
Objectivity in science is a value that informs how science is practiced and how scientific truths are created. It is the idea that scientists, in attempting to uncover truths about the natural world, must aspire to eliminate personal biases, a priori commitments, emotional involvement, etc...
-analysed global
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
grids at 1°
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
horizontal resolution, interpolated
Interpolation
In the mathematical field of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points....
onto 33 standardised vertical intervals from the surface (0 m) to the seafloor
Seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...
(5500 m). In terms of temporal
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
resolution, the relative scarcity of the source data mean that, unlike the World Ocean Atlas
World Ocean Atlas
The World Ocean Atlas is a data product of the Ocean Climate Laboratory of the National Oceanographic Data Center . The WOA consists of a climatology of fields of in situ ocean properties for the World Ocean...
, averaged fields are only produced for the annual time-scale. The GLODAP climatology is missing data in certain oceanic provinces including the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
, the Caribbean Sea
Caribbean Sea
The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles, and to the east by the Lesser Antilles....
, the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
and the Malay Archipelago
Malay Archipelago
The Malay Archipelago refers to the archipelago between mainland Southeastern Asia and Australia. The name was derived from the anachronistic concept of a Malay race....
.
Additionally, analysis has attempted to separate natural from anthropogenic DIC, to produce fields of pre-industrial
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...
(18th century) DIC and "present day" anthropogenic CO2. This separation allows estimation of the magnitude of the ocean sink
Carbon dioxide sink
A carbon sink is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period. The process by which carbon sinks remove carbon dioxide from the atmosphere is known as carbon sequestration...
for anthropogenic CO2, and is important for studies of phenomena such as ocean acidification
Ocean acidification
Ocean acidification is the name given to the ongoing decrease in the pH and increase in acidity of the Earth's oceans, caused by the uptake of anthropogenic carbon dioxide from the atmosphere....
. However, as anthropogenic DIC is chemically and physically identical to natural DIC, this separation is difficult. GLODAP used a mathematical technique known as C* (C-star) to deconvolute
Deconvolution
In mathematics, deconvolution is an algorithm-based process used to reverse the effects of convolution on recorded data. The concept of deconvolution is widely used in the techniques of signal processing and image processing...
anthropogenic from natural DIC (there are a number of alternative methods). This uses information about ocean biogeochemistry
Biogeochemistry
Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment...
and CO2 surface disequilibium together with other ocean tracers including carbon-14, CFC-11 and CFC-12 (which indicate water mass
Water mass
An oceanographic water mass is an identifiable body of water with a common formation history which has physical properties distinct from surrounding water...
age) to try to separate out natural CO2 from that added during the ongoing anthropogenic transient. The technique is not straightforward and has associated errors, although it is gradually being refined to improve it. Its findings are generally supported by independent predictions made by dynamic models.
Gallery
The following panels show sea surface concentrations of the fields prepared by GLODAP.  |
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See also
- Biological pumpBiological pumpIn oceanic biogeochemistry, the biological pump is the sum of a suite of biologically-mediated processes that transport carbon from the surface euphotic zone to the ocean's interior.-Overview:...
- Continental shelf pumpContinental shelf pumpIn oceanic biogeochemistry, the continental shelf pump is proposed to operate in the shallow waters of the continental shelves, acting as a mechanism to transport carbon from surface waters to the interior of the adjacent deep ocean.-Overview:Originally formulated by Tsunogai et al. , the pump is...
- Ocean acidificationOcean acidificationOcean acidification is the name given to the ongoing decrease in the pH and increase in acidity of the Earth's oceans, caused by the uptake of anthropogenic carbon dioxide from the atmosphere....
- Solubility pumpSolubility pumpIn oceanic biogeochemistry, the solubility pump is a physico-chemical process that transports carbon from the ocean's surface to its interior.-Overview:...
- World Ocean AtlasWorld Ocean AtlasThe World Ocean Atlas is a data product of the Ocean Climate Laboratory of the National Oceanographic Data Center . The WOA consists of a climatology of fields of in situ ocean properties for the World Ocean...
- World Ocean Circulation ExperimentWorld Ocean Circulation ExperimentThe World Ocean Circulation Experiment was a component of the international World Climate Research Program, and aimed to establish the role of the World Ocean in the Earth's climate system...