Have it ever occurred to your mind that the effects of ocean currents play a big role in human and marine life the climate?
Before jumping in more deep to the topic, it is important to know that ocean currents are a continuous movement of a large mass of water that moves in a fixed path on the surface.
The currents move vertically or horizontally and are vary in size and strength. They are also either on the ocean’s surface or in its depth below 400 meters.
The average speed of a current is considered high up to 10 km/hr. It’s possible for a current to be slow moving too at an average speed of 2 km/hr.
Water density, salinity differences, tides, temperatures, and Orison Effect that is caused by earth’s rotation drive the ocean currents, but wind specifically plays a major role in the movement and direction of the currents. Strong winds move the ocean water in a definite direction. The surface water flows in the direction of the pushing action made of the winds.
The contact between the wind and the surface of the ocean creates frictions which then moves the water in circular patterns. The move is intensified by the rotation of the Earth. In the region of northern hemisphere the currents move clockwise, while they move counterclockwise in southern hemisphere.
Further reading:
Salinity and Temperature Differences
Differences in salinity and temperature are also significant in moving the ocean water. Ocean water has more heat in the equatorial region so it makes the water light. On the other hand, the polar region is colder and heavier, so it sinks before flowing towards the equator region while the light surface layers of the ocean are moved towards the poles in which they will be cooled there.
In addition to the information above, some of the major ocean currents include the Gulf Stream, Labrador Current, and Kuroshio Current in Atlantic and the Alaska Current and California Current in Pacific.
As what have been mentioned before, ocean currents have a significant impact on the climate. However, it is not the only one, there are other effects of ocean currents that have been proven affecting the ecosystem or even human life.
A. On Climate
It is undeniable ocean currents have effects on climate. Winds that gust over cold currents will drop the temperatures of the region when they reach the land. Those kind of winds contain no moisture, therefore they will bring no rainfall and keep the hotter region cool. For example, the California Current which makes some place in the western coast of USA have a lower temperature than some others on the same latitude.
On the other hand, winds that blow over warm current will cause heavy rainfalls when they approach the land because they absorb moisture. As an example, Gulf Stream which originates in the Gulf of Mexico moves to the northern side of the earth will keep the temperatures in a few places in Europe warmer than the other parts of the region even if they stand in the similar latitudes. This is exactly why the climate effect of ocean currents influences the agricultural of the region as well.
Having a comparable function as a conveyer belt, ocean currents are responsible in transporting warm water and precipitations from the equator towards the poles and brings cold water from the poles back to the equator. Therefore, ocean currents helps to counteract the irregular distribution of solar radiation emitting to the Earth’s surface. Without ocean currents as the regulator of global climate, temperatures in the equator regions would be extremely hot whereas the poles will be so much colder and these place wouldn’t be habitable.
In the more detailed facts, the size, depth, and location of ocean currents have a significant role in regulating their effects on the climate. Shorter surface currents play a key role in affecting the local atmospheric conditions and also impacting short-term weather patterns. Unstable temperatures also control the amount of water in the atmosphere which then creates storms or dry temperatures.
Shorter horizontal ocean currents primarily affect the exchange of cooler and deeper ocean water with warmer water on the surface. This interchange revises the temperatures of the ocean water and influence the peripheral air temperature through the up welling and down welling process. As up welling brings water to the surface elevating the surrounding air temperatures, down welling takes place when ocean currents move large amount of cold water to the surface. This water will then cool the surrounding air.
Larger Ocean Currents
For larger ocean currents, they bring colder water towards the equator and warmer water towards the poles. Just like the smaller scale of ocean currents, the larger ones also modify temperatures across the globe. They influence the seasonal temperatures by moving heat energy across the world’s oceans. All these movements and exchanges of water by the ocean currents cycle nutrients throughout the ocean system.
In general, the ocean is a very complex system and its currents have a significant role in affecting the world’s climate. Even the majority of the sun’s radiation is absorbed by the ocean. Currents in tropical water acts as an enormous heat-retaining solar panel. In addition, ocean currents also help to distribute heat throughout the globe.
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B. On Marine Biology
Ocean currents play a significant factor in the fisheries or economic activities of the region because they affect both the marine ecosystem and reproduction or food chains of marine life. When the winds blow over the coastline, a biological event called up welling occurs. Up welling currents move warm water in the surface and bring out nutrient-rich water from the ocean floor to the surface. The water from the ocean floor contains high nutrients because dead sea creatures sink to the ocean bottom and decay, filling the water with nutrients.
This biological event is important for the growth of marine creatures in the surface that have limited mobility because they need those nutrients to survive. Limited mobility marine creatures include phytoplankton and seaweed have an important role in the food webs. They produce the energy base for higher level consumers in the food chains including mammals, fish, or even human. This is why up-welling areas are usually rich marine life.
Not only upwelling areas, the meeting points of warm and cold currents are also perfect for the growth of plankton that are food for fish. The productivity is high in these meeting points, thus most of them have evolved into major fishing grounds for human. One of the most famous fishing centers in the world is Newfoundland in North America, where the Labrador current and the Gulf Stream meet. Fishermen have to be careful when fishing in these places though, because they are usually thick with fog.
C. On Alternative Energy
Most of the energy we use for daily activities come from fossil fuels such as crude oil, natural gas, or coal.
Today, due to the growing population there is barely enough fossil fuels to support our life because they are a non-renewable energy source. It is uncertain if in the future we will have enough energy supply. This is where ocean currents have their role.
The surface currents are basically untapped storage of energy. Since water is dense, it carries a massive amount of energy that could be very likely to be captured. To transform the energy into a usable form, water turbines are needed. Because of the water density and the currents are strong, energy from ocean currents is perfect for large scale developments. They produce more energy than wind powers.
Into the more detailed process, the water is pumped into the turbine, which acts like a hand crank. To turn the shaft which is the power source, water hits the hand blades. The surface of water will then flow steadily in a prevailing direction. The impact of ocean current energy resources are located off the coasts of every continent on Earth. They are basically a form of stored solar and wind power. The turbines that are submerged under water are also almost identical to wind turbines.
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D. On Shipping and Navigation
Ocean currents are actually significant in reducing shipping costs throughout the heavily affected areas by strong currents, especially in these days where fuel costs are increasing. It’s been proven that with optimal current routing, a lot of shipping costs can be saved. Ships sailing along with the same current direction gain a lot of speed, thus not only able to save the fuel but also helps in reducing time spent in the sea. Contrarily, ships moving against a current will be losing speed and waste a lot of fuel.
Ocean currents also have an important factor in the safety of shipping world. The Labrador Current for example, plays a significant role in removing icebergs in the shipping lanes of Arctic regions. Icebergs are dangerous for ships, but the warm Labrador Current keeps the sea free from them. This is why it is important to have a lot knowledge about currents.
See also: Ocean Natural Resources
Advantage of Ocean Currents
Another advantage of the usage of ocean currents as an alternative energy is that the energy doesn’t produce air pollution, greenhouse gases, or water pollution. Though the safety of the marine life and ecosystem used to be one of the main concerns, it’s been proven that there are no negative effects of the turbines. Advanced technology has made it possible to create turbines with safety records in high operating efficiency.
This experimental technology is being held by some of developed countries like United States, China, Japan, and some European Union countries like United Kingdom, Germany, and France. These countries have also been having some other experiments and researches regarding ocean currents with their respective geographers and meteorologists.
Based on the thousands of research regarding this topic, it is undeniable that the effects of ocean currents lie heavily on the climate side. Covering around 71 percent of the earth’s surface, the ocean is a major element of the climate system. Thus, the stability of ocean circulation including ocean currents is very significant in maintaining the safety of the solar system.
How a change in Ocean Currents
We’ve seen some severe demonstrations of how a change in ocean currents could negatively affect climate conditions. The present El Niňo in Pacific Ocean has brought up changes in the usual consistent weather patterns across the world since it hit Humboldt Current.
One of the predominant effects of the event, other than temperature changes and track of storms, is disruption of ocean currents. The phenomenon which occurs every 2-7 years is identified with the warming up surface water temperatures on South American coast.
El Niňo has led to some of the critical consequences in the region like the decrease of fish populations which then has affected the economic, specifically fishing communities in Peru and Ecuador.
The event has some negative effects on the region’s agricultural production too because of drought and floods. The warmer temperatures in the region has also led to the outbreak of some virus diseases.
As if El Niňo hasn’t sparked enough concerns, new study conducted by scientists and experts shows that global warming is slowing down the ocean currents. It is shown that the rapid melting of polar ice has been slowing down the ocean currents in Atlantic Ocean. If too much ice melts in the region, a freshening of the cold salt water could happen. If the water is less salty, it will also be lesser in density which then will reduce its likelihood to sink below the surface. This could slow down or even shut down the ocean circulation. In fact, it is said that The Gulf Stream particularly is slowing down more than it has in 1000 years.
The slowdown has led to some of the coldest temperatures ever recorded in the south of Greenland and Iceland. It is highly possible that in the future North America and Europe would experience colder temperatures. It would also result in sea level rise in some cities like Boston and New York. Scientists even fear this could lead to unproductive fisheries in North Atlantic which is one of the major fishing grounds in the world.
See also: Marine Protected Areas
The Gulf Stream
Though scientists say shutdown of the Gulf Stream might happen a lot sooner than the Intergovernmental Panel on Climate Change (IPCC) report predicts, they also assure that the complete shutdown of The Gulf System will not happen until decades. Nevertheless, the new research does indeed find that global warming seems to be slowing down the ocean circulation. And while it might not be that apocalyptic, it is still not a good news. It is still a bad news for cities like Boston and New York because the possibility of rising sea level in those areas remains high.
Ocean currents can actually have an effect on the oxygen levels too, based on a book by Peter D.Ward titled “Under a Green Sky:
- Global warming,
- The mass extinctions of the past, and what they can tell us about our future.
The melting ice due to global warming is capable in releasing cold water into the ocean and disrupts the its currents that move deeper water to shallow and keep oxygen in the ocean. This disruption may lower oxygen levels and eventually results in a “Canfield ocean” environment, where living organisms that depends on oxygen can’t survive.
Effects of Circulation Changes
In reality, the effects of circulation changes on marine ecosystem are still largely unexplored and will probably be serious. In addition, a weakened ocean circulation also reduces the ocean’s capability to absorb carbon dioxide, making the climate system even less forgiving of the emissions. But even if is currently not very concerning, the effects of ocean currents in human’s life is irrefutable.
Our life depends heavily on the nature, including marine ecosystem. The ocean currents can only do so much in easing our life. Even if there’s so many advantages of ocean currents to the Earth, with the current conditions, human needs to rack their brains to think about the safety of their future. Now that we know the climate change can endanger the effects of ocean currents to our life, the least we can do is use less and save up energy in our daily life.
See also: Effects of Sea Level Rise
Just like the prominent Indians’ figure Chief Seattle once said, “Humankind has not woven the web of life. We are but one thread within it. Whatever we do to the web, we do to ourselves. All things are bound together, all things connect”. We have to respect nature as it is the best gift we have to treasure. By destroying the nature, we are destroying ourselves too. So let’s take care of the oceans that we depend on to aim a bright future.