Upwelling is a process in which deep, cold water rises toward the surface. ... Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients . These nutrients “fertilize” surface waters, meaning that these surface waters often have high biological productivity.
What causes the cold water to come to the surface during upwelling?
process in which cold, nutrient-rich water from the bottom of an ocean basin or lake is brought to the surface due to atmospheric effects such as the Coriolis force or wind .
What happens to this cold Upwelled water during an El Nino event?
During El Niño, upwelling of cooler oceanic water decreases along the S. ... America to Asia/Australia , and warm surface water is dragged away from the coast and colder, nutrient water rises to shallow depths.
Is the upward movement of cold deep nutrient-rich water to the surface?
Upwelling is vertical upward movement of water, often due to Ekman divergence. The divergence of water at the surface causes deeper water to upwell to the surface. ... Convergence of water at the surface prevents the upwelling of cold, nutrient-rich water, causing thicker thermocline.
What happens downwelling?
Downwelling occurs when the water on the surface of the sea becomes denser than the water beneath it and so it sinks . Seawater gets denser when it gets colder or saltier. ... The water brought in by the surface gyres is pretty salty already, because it comes from the tropics, where evaporation increased salinity.
How do upwellings and Downwellings form?
Coastal Upwelling
Upwelling and downwelling also occur along coasts, when winds move water towards or away from the coastline . Surface water moving away from land leads to upwelling, while downwelling occurs when surface water moves towards the land.
What causes Deepsets?
In contrast to wind-driven surface currents, deep-ocean currents are caused by differences in water density . The process that creates deep currents is called thermohaline circulation—“thermo” referring to temperature and “haline” to saltiness. ... This water also cools and sinks, keeping a deep current in motion.
How does El Niño affect the water cycle?
It is well known that evaporation rates increase as temperature rises. ... During El Niño periods, reduced precipitation in these regions leads to lower terrestrial moisture content, so there is less water in the soil available to evaporate.
What happens to the ocean during ENSO?
This in turn slows the ocean current that draws surface water away from the western coast of South America and reduces the upwelling of cold, nutrient–rich water from the deeper ocean, flattening out the thermocline and allowing warm surface water to buld in the eastern part of the basin.
How El Niño develops over the equatorial Pacific Ocean?
An El Niño condition occurs when surface water in the equatorial Pacific becomes warmer than average and east winds blow weaker than normal . The opposite condition is called La Niña. During this phase of ENSO, the water is cooler than normal and the east winds are stronger. El Niños typically occur every 3 to 5 years.
How are gyres formed?
An ocean gyre is a large system of circular ocean currents formed by global wind patterns and forces created by Earth’s rotation . The movement of the world’s major ocean gyres helps drive the “ocean conveyor belt.” The ocean conveyor belt circulates ocean water around the entire planet.
What is the phenomenon called when surface waters move off a coastline and deep nutrient-rich water moves up to fill the void?
Upwelling occurs when winds push surface water away from the shore and deeper water rises to fill the gap. During upwelling, wind-displaced surface waters are replaced by cold, nutrient-rich water that wells up from below.
What is the movement of cold nutrient-rich waters from the bottom of the ocean promoting algae growth?
The upward movement of this deep, colder water is called upwelling . The deeper water that rises to the surface during upwelling is rich in nutrients. These nutrients “fertilize” surface waters, encouraging the growth of plant life, including phytoplankton.
Where does downwelling typically occur?
Locations. Downwelling occurs in areas such as in the subpolar gyre of the North Atlantic where several surface currents meet , where cold waters meet warmer waters, such as along the outermost boundary of the Southern Ocean where cold Antarctic water sinks below warmer South Pacific and South Atlantic waters.
What does ocean downwelling do to surface waters?
Winds blowing across the ocean surface push water away. ... The reverse process, called “downwelling,” also occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom .
Is downwelling a divergence or convergence?
Because mass is conserved, convergence in one area requires an equal amount of divergence somewhere else to balance it. To summarize: convergence usually means downwelling , divergence usually means upwelling, and upwelling frequently (but not always) is associated with enhanced biological productivity.
Why are Downwellings important for marine environments?
Currents also are a major factor in ocean ecosystems. Two types of current motion, upwelling and downwelling, strongly influence the distribution and abundance of marine life . ... When currents upwell, or flow up to the surface from beneath, they sweep vital nutrients back to where they’re needed most.
How El Niño develops?
El Niño occurs when warm water builds up along the equator in the eastern Pacific. The warm ocean surface warms the atmosphere, which allows moisture-rich air to rise and develop into rainstorms . ... During El Niño years, such as 1997, the southeast receives more rain than average.
Which current is produced by upwelling of cold water?
Peru Current, also called Humboldt Current , cold-water current of the southeast Pacific Ocean, with a width of about 900 km (550 mi). The cold flow is intensified by upwelling of deep water caused by the combined effects of the drag of surface winds of the Southeast Trades and the Earth’s rotation.
What is the horizontal movement of water below the surface?
| A B | ocean currents the movement of ocean water that follows a regular pattern | surface currents the horizontal movement of ocean water that is caused by wind and that occurs near the ocean’s surface | deep current a streamlike movement of ocean water far below the surface |
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What causes El Nino and La Nina phenomena?
Why do El Niño and La Niña occur? El Niño and La Niña result from interaction between the surface of the ocean and the atmosphere in the tropical Pacific . Changes in the ocean impact the atmosphere and climate patterns around the globe. In turn, changes in the atmosphere impact the ocean temperatures and currents.
What does La Niña cause?
La Niña is a phenomenon that describes cooler than normal ocean surface temperatures in the Eastern and Central Pacific Ocean, regions close to the equator off the west coast of South America. In some parts of the world, La Niña causes increased rainfall , while in other regions, it causes extreme dry conditions.
What are the 3 stages of ENSO?
- The neutral phase. ...
- El Niño. ...
- La Niña.
Is 2021 an El Niño year?
(WSFA) – It’s back again! La Niña conditions have officially developed and are expected to remain in place through the entirety of winter 2021-2022 . So what exactly does that mean? La Niña means we’re in the negative phase of the El Niño Southern Oscillation, or ENSO for short.
What happens during ENSO?
During ENSO neutral conditions, surface trade winds blow westward across the equatorial Pacific Ocean . Blowing against the ocean’s surface, these winds result in a westward current. During El Niño conditions, the usually present east to west winds weaken and an anomalous west to east flow develops.
Where does warm water accumulate in the Pacific Ocean during El Niño the east the south the north the West?
This warm water accumulates in the western Pacific . During El Nino conditions, the NE trade winds weaken, and can cease altogether or even change direction. The large mass of warm water, which is normally confined to the western Pacific, now moves eastward across the Pacific basin toward the coast of Peru.
Which statement best describes how nutrients move in the ocean as a result of upwelling?
Which statement best describes how nutrients move in the ocean as a result of upwelling? Nutrients move from estuaries into the intertidal zone.
What is the most abundant gas found in ocean water?
| Gas Percent of volume or pressure Partial pressure, Torr | Nitrogen 78.03 593.02 | Oxygen 20.99 159.52 | Argon 0.94 7.144 | Carbon 0.03 0.228 |
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Which is the main source of dissolved oxygen in the ocean?
The major biological source of dissolved oxygen in the ocean comes from photosynthesis by phytoplankton .
Where does warm water accumulate in the Pacific Ocean during El Niño?
The cycle begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. Normally, this warm water pools near Indonesia and the Philippines. During an El Niño, the Pacific’s warmest surface waters sit offshore of northwestern South America .
What are El Niño events?
During an El Niño event, the surface waters in the central and eastern Pacific Ocean become significantly warmer than usual . ... It also reduces the upwelling of cooler, nutrient-rich waters from the deep—shutting down or reversing ocean currents along the equator and along the west coast of South and Central America.
What are the 5 major gyres?
Gyres are large systems of circulating ocean currents, kind of like slow-moving whirlpools. There are five gyres to be exact— the North Atlantic Gyre, the South Atlantic Gyre, the North Pacific Gyre, the South Pacific Gyre, and the Indian Ocean Gyre —that have a significant impact on the ocean.
Are gyres surface currents?
The global pattern of winds together with the Coriolis Effect and Ekman Transport produce large-scale currents in the world ocean. Ocean surface currents organize into Gyres that are characterized by circulation at the scale of the ocean basin.
How does the South Atlantic Gyre circulate?
The South Atlantic Gyre is a subtropical gyre located in the southern Atlantic Ocean. Northwesterly (or southeastward-flowing) winds drive eastward-flowing currents in the gyre’s southern section, which are difficult to differentiate from the northern boundary of the Antarctic Circumpolar Current.
What causes cold nutrient rich waters to move up to the ocean’s surface?
Ocean surface currents are produced by major overall patterns of atmospheric circulation, the Coriolis Effect and the shape of each ocean basin. ... Upwelling areas are biologically important areas that form as ocean surface waters are blown away from a shore, causing cold, nutrient rich waters to rise to the surface.
What happens to this cold Upwelled water during an El Nino event?
During El Niño, upwelling of cooler oceanic water decreases along the S. ... America to Asia/Australia , and warm surface water is dragged away from the coast and colder, nutrient water rises to shallow depths.
How does the cold and denser water masses sink to the depths of ocean?
How does the cold and denser water masses sink to the depths of ocean? Explanation: The cold and denser water masses formed by surface water sink to the depths of the ocean by thermohaline circulation . It is circulation of ocean water due to density gradient.
What does downwelling cause?
Downwelling is where surface water is forced downwards , where it may deliver oxygen to deeper water. Downwelling leads to reduced productivity, as it extends the depth of the nutrient-limited layer. Upwelling occurs where surface currents are diverging, or moving away from each other.
What are the two major sources of cold ocean water in the global conveyor belt?
This motion is caused by a combination of thermohaline currents (thermo = temperature; haline = salinity) in the deep ocean and wind -driven currents on the surface. Cold, salty water is dense and sinks to the bottom of the ocean while warm water is less dense and remains on the surface.
How does coastal downwelling occur?
Downwelling occurs when surface waters converge (come together), pushing the surface water downwards . ... In these coastal upwelling regions, surface winds push water away from the shore and create a divergence at the coast, which is replaced by water from depth.
