The
Global Ocean Data Analysis Project (
GLODAP) is a synthesis project bringing together
oceanographicOceanography , 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 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...
(WOCE), Joint Global Ocean Flux Study (JGOFS) and Ocean-Atmosphere Exchange Study (OACES) programmes. The central goal of GLODAP is to generate a global
climatologyClimatology 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 OceanThe World Ocean, world ocean, or global ocean is the interconnected system of the earth's oceanic waters, and comprises the bulk of the hydrosphere....
's
carbon cycleThe 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-forcedGreenhouse gases are gases in an atmosphere that absorb and emit radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The main greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
states.
The
Global Ocean Data Analysis Project (
GLODAP) is a synthesis project bringing together
oceanographicOceanography , 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 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...
(WOCE), Joint Global Ocean Flux Study (JGOFS) and Ocean-Atmosphere Exchange Study (OACES) programmes. The central goal of GLODAP is to generate a global
climatologyClimatology 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 OceanThe World Ocean, world ocean, or global ocean is the interconnected system of the earth's oceanic waters, and comprises the bulk of the hydrosphere....
's
carbon cycleThe 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-forcedGreenhouse gases are gases in an atmosphere that absorb and emit radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The main 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 AdministrationThe National Oceanic and Atmospheric Administration 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 EnergyThe 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 FoundationThe 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 carbonThe 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 anion. It is customary to express carbon dioxide and carbonic acid simultaneously...
(DIC),
alkalinityAlkalinity or AT is a measure of the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. Alkalinity is closely related to the acid neutralizing capacity of a solution and ANC is often incorrectly used to refer to alkalinity.The alkalinity is...
,
carbon-14Carbon-14,
14C, or radiocarbon, is a radioactive isotope of carbon discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, though its existence had been suggested already in 1934 by Franz Kurie. Its nucleus contains...
(
14C), CFC-11 and CFC-12. The fields consist of
three-dimensionalThree-dimensional space is a geometric model of the physical universe in which we live. The three dimensions are commonly called length, width, and depth , although any three mutually perpendicular directions can serve as the three dimensions....
, objectively-analysed
globalEarth is the third planet from the Sun. It is the fifth largest of the eight planets in the solar system, and the largest of the terrestrial planets in the Solar System in terms of diameter, mass and density...
grids at 1
°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,
interpolatedIn the mathematical subfield 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
seafloorThe seabed is the bottom of the ocean. At the bottom of the continental slope is the continental rise, which is caused by sediment cascading down the continental slope. The seabed has been explored by submersibles such as Alvin and, to some extent, scuba divers with special apparatuses...
(5500 m). In terms of
temporalTime is a component of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify the motions of objects...
resolution, the relative scarcity of the source data mean that, unlike the
World 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...
, averaged fields are only produced for the annual time-scale. The GLODAP climatology is missing data in certain oceanic provinces including the
Arctic OceanThe 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 International Hydrographic Organization recognizes it as an ocean, although some...
, the
Caribbean SeaThe Caribbean Sea is a sea of the Atlantic Ocean situated in the tropics of the Western hemisphere, bounded to the south and west by the American landmass, with the North Atlantic Ocean proper to the northeast and the Gulf of Mexico to the northwest...
, the
Mediterranean SeaThe 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 Africa, and on the east by the Levant. The sea is technically a part of the Atlantic Ocean, although it...
and the
Malay ArchipelagoThe Malay Archipelago and Maritime Southeast Asia are names given to the archipelago located between mainland Southeastern Asia and Australia. Located between the Indian and Pacific Oceans, the group of 20,000 islands is the world's largest archipelago by area...
.
Additionally, analysis has attempted to separate natural from anthropogenic DIC, to produce fields of pre-
industrialThe Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, and transport had a profound effect on the socioeconomic and cultural conditions in the United Kingdom. The changes subsequently spread throughout Europe, North...
(1700s) DIC and "present day" anthropogenic CO
2. This separation allows estimation of the magnitude of the ocean
sinkA carbon sink is a natural or manmade reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period.The main natural sinks are:*Absorption of carbon dioxide by the oceans*Photosynthesis by plants and algae...
for anthropogenic CO
2, and is important for studies of phenomena such as
ocean acidificationOcean acidification is the name given to the ongoing decrease in the pH of the Earth's oceans, caused by their 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
deconvoluteIn 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
biogeochemistryThe field of biogeochemistry involves scientific study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment , and the cycles of matter and energy that transport the Earth's chemical components in time and space...
and CO
2 surface disequilibium together with other ocean tracers including carbon-14, CFC-11 and CFC-12 (which indicate
water massAn oceanographic water mass is an identifiable body of water which has physical properties distinct from surrounding water. Properties include temperature, salinity, chemical - isotopic ratios, and other physical quantities....
age) to try to separate out natural CO
2 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.
See also
- Biological pump
In 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 pump
In 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 acidification
Ocean acidification is the name given to the ongoing decrease in the pH of the Earth's oceans, caused by their uptake of anthropogenic carbon dioxide from the atmosphere...
- Solubility pump
In oceanic biogeochemistry, the solubility pump is a physico-chemical process that transports carbon from the ocean's surface to its interior.-Overview:...
- 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...
- 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...