Ocean Circulation

At the surface, ocean currents are driven by the winds, which make the surface water move parallel to the predominant wind direction, except

Global Ocean Conveyor Belt

The surface ocean circulation transports heat globally, maintaining temperatures and supporting marine life. The principal warm and cool currents control climate locally, regionally, and globally.

where continental landmasses exist and block its movement. Water also moves vertically in the ocean depths. There are two factors that make water more dense (which causes it to sink) or less dense (which keeps it on the surface): (1) salt content and (2) temperature.

Atmospheric flow and ocean currents are the mechanisms that carry heat from the equator to the poles. There are many processes that can alter the circulation patterns, which can change the weather of an area. Variations can happen on cycles that last months, years, decades, or centuries. Variations can also affect deepwater or surface water. If the ocean did not distribute heat throughout the world, the equator would be much warmer and the poles would be much colder.

The oceans are equally important as the atmosphere in transporting heat from the equator to the polar regions. In terms of how much heat and water it can hold, its capacity is much greater than the atmosphere's. In fact, the world's oceans can store approximately 1,100 times more heat than the atmosphere. The oceans also contain 90,000 times more water than the atmosphere does.

As more knowledge is gained about global warming, a better appreciation of the role the oceans play in shaping the Earth's climate is also gained. Because of this, much more research has been done on the oceans in the past 15 years, leading to the discovery that the oceans' depths have warmed considerably since 1950. According to scientists at the Woods Hole Oceanographic Institution, until recently, scientific models predicting climate change could not account for where the projected warmth had gone—it was unaccounted for in the atmosphere. This discrepancy in the model had caused much confusion until researchers finally figured out that the missing greenhouse warming was being stored by the world's oceans. Water has a tremendous capacity to hold heat. The warming had occurred, but no one had thought to look toward the oceans for the answer.

Now that scientists understand this relationship, those who study global warming agree that including the ocean system in global warming studies is critical. Not only do the oceans have an enormous ability to hold heat, the constant movement of slow and fast water can affect the weather for months at a time. It is important for climatologists to understand these ocean interactions in order to be able to predict regional trends in climate. It is also important to understand deepwa-ter processes and processes that occur near the surface to understand what mechanisms drive climate.

The oceans also play a critical role in balancing the carbon dioxide (CO2) levels. The CO2 levels in both the atmosphere and the ocean reach an equilibrium. If something happens to upset this balance— such as changes in chemistry—then sudden shifts in the CO2 levels can affect the climate. This is one of the concerns about the steadily increasing levels of greenhouse gases. If the oceans reach the point where they cannot absorb CO2, it could upset the balance of ocean currents and climate patterns on a global scale.

Was this article helpful?

+2 -1

Post a comment