Summary
The episode of "Stuff You Should Know" titled Selects: How Ocean Currents Work provides an in-depth look at the Earth's ocean currents, their formation, and their importance in maintaining a balanced global ecosystem. The hosts discuss various types of currents, including coastal, surface, and deep ocean currents, and their effects on the environment. They also delve into oceanic gas exchange and how it compares to the human cardiopulmonary system, the global nutrient swap, and the influence of tidal currents.
Surface currents are produced by wave action, which starts with heat and is affected by wind. Different types of surface currents include coastal currents, longshore currents, and riptide currents. Another essential aspect of ocean currents is upwelling and downwelling, vertical motions caused by coastal and wind influences. These processes allow for the essential exchange of nutrients and gases, such as oxygen and CO2, which supports marine life and prevents unfavorable conditions.
The episode also explores the Coriolis effect, the phenomenon responsible for creating large, circular ocean currents called gyres. There are five main gyres: the North Atlantic, South Atlantic, North Pacific, South Pacific, and Indian Ocean gyres. These have a significant impact on nutrient circulation and weather patterns.
Deep ocean currents, also known as the global conveyor belt, make up 90% of the ocean's water. Driven by density, this massive current system circles the globe and takes thousands of years to complete a full cycle. The conveyor belt is responsible for the global nutrient swap, where nutrients and gases are redistributed around the world.
Tidal currents play an essential role in ecosystems, as they are affected by the gravitational pull of both the moon and the sun, with the moon having a more significant impact. The tidal forces can cause rising and falling water levels along coastlines and impact where fish lay their eggs or wash food in and out of marshlands.
The episode concludes with a discussion on the potential effects of climate change on ocean currents. The melting icebergs and global warming may disrupt the global conveyor belt by reducing the salinity and temperature of ocean water, preventing cold, dense waters from sinking. This disruption could have far-reaching consequences for global ecosystems and the nutrient exchange process. Overall, this episode highlights the intricate and vital roles ocean currents play in maintaining the Earth's environmental balance.
