By Jonny Lupsha, Wondrium Staff Writer
The Gulf Stream is slowing down in its movement. Its flow regulates the climate and affects temperatures and sea levels. The major ocean current is created by wind friction and water density differences.
Surface currents like the Gulf Stream affect the uppermost 10% of the world’s oceans, carrying tropical waters to the poles and colder waters to the equator. Recent studies of the Gulf Stream suggest that this global current system could reach a tipping point and virtually stop flowing by the year 2100.
If that happens, extreme heat waves and cyclones could affect both sides of the Atlantic Ocean, cause sea levels to rise, and more. How does this happen? In his video series Oceanography: Exploring Earth’s Final Wilderness, Dr. Harold J. Tobin, Professor of Geoscience at the University of Wisconsin–Madison, explained the incredible system of ocean currents.
“Really big currents that we think about, like the Gulf Stream, are surface currents of the ocean that are caused mainly by wind friction directly on the sea surface, just as the waves are, and then also by differences in the density of different water masses and differences in the heat and density characteristics of those water masses,” Dr. Tobin said.
According to Dr. Tobin, surface currents are induced by prevailing winds, most clearly conveyed by westerlies and trade winds. While trade winds blow from the northeast to the southwest, westerlies blow in the opposite direction and in different latitudinal bands.
“[Western boundary currents] move warm water from the tropical regions to higher latitudes, so they’re a major component in the heat redistribution on the planet, redistributing that heat generated in the equatorial regions to the high latitudes,” Dr. Tobin said. “The largest and most famous to us in the western boundary currents is the Gulf Stream.”
Gulf Stream Characteristics
Dr. Tobin said that the Gulf Stream moves at two meters per second, which is approximately five miles per hour. He compared it to a river in the ocean. It’s also an unbelievable volume of water.
“It flows at a rate of 55 million cubic meters of water per second,” he said. “Cubic meter of water is a large volume of water, and 55 million of them per second pass any given point. Just for perspective, the entire global input of fresh water from all the rivers in the whole world to the ocean is approximately [one million cubic meters of water per second].
“The Gulf Stream is moving 55 times the flow of all the rivers of the entire planet, and it’s doing that year in and year out.”
Oceanographers can see the Gulf Stream flowing; its sharp boundaries mean that it’s kept intact by its rapid flow and distinct differences in water density. Satellite imagery shows that it starts in the Caribbean and works its way north along the East Coast of the United States until it detaches from North America around Cape Hatteras, moving out across the North Atlantic Ocean.
This vital part of our global climate is larger and more fundamental to the planet than most of us imagine. We can only hope it will continue to flow in the years to come.