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# Simulating the Global Ocean

Complex equations representing the physical, biological, and chemical properties of the ocean make up the computer models oceanographers use to learn how massive amounts of ocean water move and influence the rest of the world.

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### Subjects

Earth Science, Meteorology, Oceanography

Selected text level

The United Kingdom and Ireland are known for their chilly weather. However, their coasts, like those of other Western European countries, tend to be pleasantly warm. Western Europeans can thank ocean currents for that.

Ocean currents are continuously flowing movements of water. They are found on the ocean's surface and underwater. One major ocean current is the Gulf Stream, which transports enormous amounts of warm water from the Gulf of Mexico into the seas of Western Europe.

The ocean has several major currents like the Gulf Stream. These currents affect weather, ecosystems, and life all over the world. The worldwide movement of these currents in the ocean is called ocean circulation.

Oceanographers are scientists who study the seas, including their circulation. Some of these scientists work to develop and improve computer programs known as models that represent, or simulate, something that can or could take place in the real world. Given the complexity of the oceanic environment, computer models are important tools for scientists trying to explore the deepest secrets of the ocean.

Predicting Ocean Behavior

Computer models of the ocean use calculations to solve complex mathematical equations. These calculations represent the behaviors of a complicated system like the ocean. For example, parts of the ocean system, such as temperature and salinity, or the levels of salt, are constantly changing.

The models seek to answer various questions. For example, how are ocean temperatures related to local weather? How does the ocean help control the global climate? These are just a couple of the questions that ocean circulation models can help address.

The ocean is an extremely challenging system to model and for this reason, scientists must consider many features. These include the shapes of coastlines, the ocean floor, and different water depths. In their calculations, ocean modelers also consider the water's temperature and density, which is the weight of a substance in a specific volume. As more data becomes available, scientists add this new data into their models to help improve them and make them more accurate representations.

With an ocean model, scientists can work to better understand the ocean as part of a larger complex system that involves climate and Earth's atmosphere, which is the layer of gasses around a planet, among other things. These kinds of models are essential for predictions of how both natural changes and human-caused changes will influence climate and life on Earth.

Interest in Modeling Ocean Behavior

Oceanography is the scientific field that studies the properties and phenomena of the ocean. This field is hundreds of years old. In the early 19th century, scientists did not know much about the circulation of the ocean, and it took oceanographers a century to trace the general patterns of ocean circulation.

In the 1940s, oceanographers began to describe ocean circulation in detail. The first accurate description of ocean circulation outlined the way that cold, dense water sinks near Iceland and Greenland and then flows south. In the 1950s, scientists measured radioactive waste from atomic-bomb tests and industrial byproduct particles dissolved in the ocean. These measurements helped oceanographers to track currents more accurately.

All of this work helped to pave the way for the earliest ocean circulation models. Since the 1960s, Earth scientists and computer scientists have worked together to improve ocean models.

In the decades after, shifting weather patterns as a result of climate change, became a growing concern. Scientists knew the ocean was the major stabilizer of global climate. They looked to developing models that would help explain the complex physical, biological, and chemical processes going on in the ocean and how it affects the planet.

Continuing To Learn about the Ocean

Ocean modeling advanced as United States government research began contributing to the field. The first ocean circulation models were produced in the late 1960s, including the first one simulating the entire ocean.

Computers advanced in the 1980s and 1990s, and supercomputers became available. Scientists also got more ocean data from satellites, research ships and floating sensors. These advances helped scientists develop models with more realistic oceanic features.

Even today, much of the ocean remains a mystery. We have better maps of the moon and Mars than we do of the ocean floor.

Ocean models generate different outcomes based on the data that is fed into them. But in the actual world, there is only one reality. Computer models just approximate the world. Nonetheless, scientists work hard to make the models correspond as closely as possible to reality. Computer models, whatever their limitations, have become a necessary tool for studying the ocean.

###### Media Credits

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###### Director
Tyson Brown, National Geographic Society
###### Author
National Geographic Society
###### Production Managers
Gina Borgia, National Geographic Society
Jeanna Sullivan, National Geographic Society
###### Program Specialists
Sarah Appleton, National Geographic Society, National Geographic Society
Margot Willis, National Geographic Society
Clint Parks
Roza Kavak

October 19, 2023