Ocean Currents

What are Ocean Currents? 

Ocean currents are similar to river flow in that they occur in large bodies of water. They indicate a consistent amount of water travelling in a particular course and direction. Ocean currents are impacted by two forces: primary forces, which begin the movement of water and secondary factors, which influence the currents to flow. 

Types of Forces: 

#1. Primary Forces: 

• Heating by Solar Energy: 

Solar energy is used to heat the water, which causes it to expand.  The ocean water level is about 8 cm greater in the middle latitudes near the equator than in the middle latitudes farther north. Water tends to flow down the slope as a result of the minor gradient created by this

• The wind blowing: 

The wind blowing on the Ocean’s surface causes the water to move. In the course of a water body’s journey, friction between the wind and the water surface impacts its movement

• Gravity: 

Gravity tends to drag the water down the pile, resulting in gradient change between the layers

• Coriolis force: 

The Coriolis force is a natural phenomenon that causes water to travel to the right in the northern hemisphere and  the left in the southern hemisphere when it intervenes

• A buildup of water occurs at the designated sites as a consequence of this
• Gyres are enormous accumulations of water that happen in the Ocean and the flow that surrounds them
• Large circular currents are generated in all of the ocean basins as a result of this

#2. Secondary Forces: 

The vertical mobility of ocean currents is affected by differences in water density is known as Secondary forces

• Salinity: 

Water with a high salinity density is denser than water with low viscosity, and cold water is thicker than warm water in the same way cold water is denser than warm water. The vertical mobility of ocean currents is affected by differences in water density 

• Temperature: 

Denser water sinks, while comparatively lighter water rises as a result of the temperature difference

• Cool water currents in the ocean arise when cold water in the poles sinks and slowly travels towards the equator as it warms up
• Warm water currents go out from the equator along the surface of the Ocean, travelling towards the poles to replace the cold water that is sinking

Characteristics of Ocean Currents: 

• Ordinarily, the ocean currents are most significant near the surface, and they may reach speeds of more than five knots
• Currents at depths are usually sluggish, moving at rates of less than 0.5 knots on average. “Drift” is the term used to describe the speed of a current. Knots are used to measure the amount of drift
• The speed of a current is referred to as the strength of the current in this case. A strong current is defined as one that moves quickly. A current’s intensity (or speed) is often most incredible near the surface and diminishes as it descends in depth
• The majority of currents move at rates of less than or equal to 5 knots, on average

Types of Ocean Currents

• Classification based on their depth: 

#1. Surface Currents: 

Surface currents account for about 10% of total oceanic water, with these fluids occupying the top 400 meters of the Ocean 

#2. Deep Water Currents: 

• They account for the remaining 90 percent of the Ocean’s water
• Because of differences in the density and gravity of the water, these waters travel across the ocean basins
• During the winter months in high latitudes, deep waters drop into deep ocean basins where the temperatures are low enough to cause the density of the water to rise

• Classification based on Temperature: 

#1. Cold currents: 

These currents transport cold water from cold water locations to warm water areas. These currents are often found on the west coasts of continents in the low and medium latitudes (which is true in both hemispheres) and on the east coasts of continents in the higher latitudes (which is true in the Northern Hemisphere) of the planet

#2. Warm currents: 

These currents transport warm water from warm water regions to cold water areas. They are most often seen on the east coasts of continents in the low and medium altitudes and on the west coasts of continents (accurate in both hemispheres). In the northern hemisphere, they may be found on the western coastlines of continents at high latitudes on the continents’ western shores

Major oceanic currents: 

• The strains produced by the wind direction and the Coriolis force significantly impact on the major ocean currents, which are described here
• The marine circulation pattern is generally equivalent to the earth’s atmospheric circulation pattern when it comes to circulation patterns
• The anticyclonic circulation of air over the seas in the middle latitudes is the predominant mode of circulation. The pattern of oceanic circulation matches that of the atmosphere
• The oceanic cycle follows this pattern in higher latitudes when the wind flow is mostly cyclonic
• In areas with a strong monsoon season flow, the prevailing winds impact the current motions of the Ocean
• It moves heat from one latitude belt to another in a way similar to that of the atmosphere’s general circulation, which transports heat from one latitude belt to another
• Water from the Arctic and Antarctic rings moves towards warmer water in tropical and equatorial areas, whereas water from lower latitudes moves poleward

Conclusion

Ocean currents are the directional flow of seawater caused by gravity, wind (Coriolis Effect), and water density. Water in the ocean flows in two directions: horizontally and vertically. Currents are horizontal motions, whereas upwellings and downwelling  represent vertical movements.