What is meant by the term thermohaline conveyor belt?

Question

What will be an ideal response?

Answer 1

The thermohaline conveyor belt is the process by which deep water is transported around the globe. Deep water first forms in the North Atlantic, where downwelling of cold waters with relatively low densities occurs. After downwelling, this deep water moves south to the Antarctic, then to the Indian and Pacific Oceans, and finally to the North Pacific where it resurfaces. The downwelling in the North Atlantic is balanced by surface flows that bring water to the North Atlantic.

The thermohaline conveyor belt is a significant feature of the Earth system in several respects: It plays a dominant role in the recycling of ocean nutrients, and it has a major impact on Earth's climate. Much of the life that exists in the oceans can be found in the near-surface layers, utilizing sunlight for photosynthesis—phytoplankton, for example—or living off the animals that feed on phytoplankton. These plants and animals use the nutrients in ocean water, so the surface layers become relatively depleted in nutrients. When these organisms die, they sink through the water column, decompose, and release the nutrients back into the water. The deeper ocean, therefore, is relatively rich in nutrients. The thermohaline circulation transports these nutrient-rich waters around the globe, returning the nutrients to the surface in areas of upwelling, primarily along the continental margins.