Ocean Currents: Surface and Deep

• Stream-like movement of ocean water in a regular pattern defines an ocean current
• There are 2 types of ocean currents: Surface and Deep Currents

Surface Currents

• Horizontal movement of water in a regular pattern at the ocean's surface is a surface current
• Global winds generally move currents in the same direction as the winds
• The Coriolis Effect curves/deflects water or air due to Earth's rotation
• Continental deflection occurs when currents deflect in a direction upon meeting continents

Deep Currents

• Density of water and gravity are factors that affect Deep Currents
• When ocean water density increases, surface water becomes denser than the water below, causing it to sink
• The regular pattern of water movement below the surface of the ocean is known as a "Deep current"
• When water density increases, water sinks to the ocean's bottom; when density decreases, water rises
• Denser water is pulled downward to the ocean floor more strongly by gravity than less dense water
• Topography of the ocean floor affects the movement and direction of deep currents

Hot and Cold Water

• Cold water has slow-moving particles with less energy than warm particles
• Compared to particles in cold water, particles in warm water bounce around more and are spread farther apart
• Warm water is less dense than cold water

Density in ocean water

• Differences in water properties affect how ocean water moves both horizontally and vertically
• Ocean water is mainly salty, but salinity varies across different parts of the ocean
• Ocean temperature also varies; at the poles, surface water temperature can be as low as -1.9 degrees Celsius, while near the equator, it can be as high as 30 degrees Celsius
• Both temperature and salinity affect water density
• As water gets colder, it becomes denser; likewise, increased salinity makes it denser

The flow of energy

• Energy transfers occur when the atmosphere and ocean water have different temperatures
• Energy transfer always happens from warmer to colder regions; if air is warmer than water, air transfers energy to the water
• Energy is transferred from the equator to the poles via ocean currents

Cycling of matter

• Ocean currents transport matter, including water, dissolved particles (like salt), gases (like oxygen or carbon dioxide), marine organisms, and waste

Carbon Cycle

• The Carbon Cycle is a biogeochemical cycle where various carbon compounds are interchanged among Earth's layers: biosphere, geosphere, pedosphere, hydrosphere, and atmosphere
• Carbon enters the atmosphere as CO2
• CO2 is absorbed by autotrophs like green plants
• Animals consume plants, incorporating carbon
• When animals and plants die, their bodies decompose, and carbon is reabsorbed into the atmosphere

Importance of Carbon Cycle

• Even in small traces, carbon dioxide plays a vital role in balancing energy and trapping long-wave radiation from the sun, acting as a blanket over the planet
• Disturbances to the carbon cycle can result in climatic changes and global warming
• Carbon is an integral component of life on Earth, from proteins and lipids to DNA
• The carbon cycle, along with the nitrogen and oxygen cycles, is vital for life on Earth