Quiz 1- global conveyor belt + abiotic factors Flashcards
State the four major abiotic factors that influence life in the ocean.
seawater temp
salinity
oxygen
light
Identify the primary drivers of seawater temperature change
1) solar input (sun)
2) mixing of other water sources
explain how solar input influences seawater temperature worldwide.
forms a temp gradient of surface water where equator has most access to sun and is the warmest
explain how mixing of other water sources influences seawater temperature worldwide.
movement of warm surface waters down and cool deep waters up?
Define salinity
the measure of dissolved inorganic solids in seawater
measured in ppt or psu (parts per thou or practical salinity units
identify the major elements found in seawater
Cl and Na
Explain why many elements in seawater are found at constant concentrations throughout the world’s oceans, and how we can use this to our advantage when calculating salinity.
- residence time (amount of time a substance spends in the water column before it settles- sediment, lost to the continents, etc.)
- The longer the residence time, the more constant you’ll find the concentration to be worldwide
- chlorine has the highest concentration in global oceans and a long residence time:
***SO we can use chlorinity measurement to estimate salinity
Describe how oxygen concentration increases and decreases in the water column.
input thru the atmosphere and photosynthetic organisms
- further down, o2 removed and not being replaced (no photosynthesis or atmospheric replacement)- respiration (eg: fish)
- lower down: decomposition is completed by bacteria, algae, etc, which all also respirate
Where is oxygen at its highest concentration, and why?
oxygen concentration is highest at the surface of the ocean BECAUSE this is where the water/air interface is AND because photosynthesizers live here bc of access to light
Describe the vertical structure of oxygen concentration in the ocean, and the factor(s) that influence this structure.
- highest at surface
- drops dramatically at the thermocline- this is the oxygen minimum layer
- (a thermocline is an area where temp changes relatively drastically compared to what is directly above and below that level)
- slowly increases as depth increases- Below thermocline there is cold, O2 rich water from poles
List the three major oceanic zones based on light.
- euphotic (sunlight) zone
- dysphotic (twilight) zone
- aphotic (midnight) zone
euphotic (sunlight) zone
sunlight
photosynthetic organisms
dysphotic (twilight) zone
NO photosynthesis
sunlight decreases rapidly with depth
aphotic (midnight) zone
no sunlight whatsoever
Hypothesize how the distance light travels through water might influence oxygen concentration.
photosynthetic organisms reside in areas that have access to sunlight
Relate oxygen concentration, temperature and salinity in the ocean. How do they impact one another?
- temp and salinity influence density
- the colder, the more o2 can be held
- temp does not have a significant effect on salinity
- o2 conc and salinity do not have a significant relationship
TRUE OR FALSE: Oceanic surface currents are influenced by planetary wind, while deep water currents are influenced by the Coriolis effect. FIX IF FALSE
FALSE:
- Oceanic surface currents are influenced by planetary wind and Earth’s rotation which together comprise the Coriolis effect.
- Deep water currents are mainly influenced by the sinking of cold and highly saline (dense) water near the poles
TRUE OR FALSE: Deepwater currents are driven by the sinking of colder, higher salinity water at the poles. FIX IF FALSE
TRUE
TRUE OR FALSE: Surface water currents are driven by upwelling, where deep water currents rise to the surface and push surface water out of the way. FIX IF FALSE
FALSE:
- Surface water currents are driven by planetary winds (which are affected by earth’s rotation, resulting in the Coriolis effect)
- Upwelling occurs when surface winds and planetary rotation at a coast lead to EKMAN TRANSPORT where the water moves 90 deg away from the coast and deep water moves in to replace it
TRUE OR FALSE: Surface water currents only sink at lower latitudes where the water becomes more dense due to increased salinity. FIX IF FALSE
FALSE:
Surface water currents SOMETIMES sink at HIGHER latitudes where the water becomes more dense due to increased salinity (AS WELL AS COLDER TEMPERATURE)
TRUE OR FALSE: Seawater density is impacted by temperature and salinity. FIX IF FALSE
TRUE
TRUE OR FALSE: Differences in seawater density drive the restrictions in vertical circulation that lead to oxygen minimum layers between 200m-1200m deep in some parts of the ocean. FIX IF FALSE
TRUE
TRUE OR FALSE: Seawater density is a primary driver of vertical circulation. FIX IF FALSE
TRUE
TRUE OR FALSE: Density drives upwelling by forcing warmer surface water away from the coast, and bringing colder water to the surface. FIX IF FALSE
FALSE:
- density does not drive upwelling!!! its caused by the conditions that lead to ekman transport
TRUE OR FALSE: Residence times explain salinity variation between the ocean and estuaries.
FALSE
TRUE OR FALSE: Residence times explain constant proportions of major elements throughout the ocean.
TRUE
TRUE OR FALSE: Residence times explain how river runoff impacts salinity in coastal environments.
FALSE
TRUE OR FALSE: Residence times explain variations in salinity at different latitudes in the global ocean.
FALSE
Define Global Conveyor Belt Circulation.
global conveyor belt circulation connects surface and deep ocean
Describe the Coriolis Effect and how it influences ocean surface waters. How does its influence differ in the southern hemisphere vs northern hemisphere?
Coriolis Effect- a deflection in surface current direction
- northern hemi: clockwise
- southern hemi: counter-clockwise
Explain the role Gyres and Boundary Currents have in the transport of ocean water, nutrients and (potentially even) living organisms.
gyres move clockwise in the Northern Hemisphere and counterclockwise in the southern hemisphere- large-scale transport of surface water from the tropics to higher latitudes
OBCs- western side of Atlantic + pacific gyres (eg: gulf stream)- very FAST and transport LARGE volumes of water- warm core and cold core rings break off (aka eddies)
eddies can transport water, nutrients, and sometimes even animals to places they may not typically be found
Define Ekman Transport and describe how this process works to influence coastal upwelling and downwelling.
the NET movement of water resulting from wind + coriolis effect (leads to water moving 90 deg either towards or away from shore line)
- Wind moves the water in the direction it’s moving- layers of water under the top move in the same direction but more and more slowly than at the top because it’s being pulled less by the wind
- coastal upwelling and downwelling depending on which way the wind blows (eg: northern hemi- wind is blowing north along the Peruvian coast, and the coriolis effect is making the water blow 90 deg clockwise (left) away from the coast and upwelling happens as deeper water replaces the surface water)
Compare and contrast the drivers of horizontal and vertical water movement in the ocean.
horizontal- wind and coriolis effect
vertical- changes in seawater density
Identify the major characteristics used to define water masses in the ocean.
temp
salinity
other physio-chemical characteristics
Define thermohaline circulation and describe the role it plays in the global conveyor belt system.
Thermohalinity = density (combination of temp and salinity)
Thermohaline circulation- how density drives vertical water movement
Understand how density relates to temperature and salinity, and the role this relationship plays in thermohaline circulation.
Colder + saltier = denser
warmer + less salty = less dense
O2 rich surface water gets colder as it moves away from equator and grabs more o2 bc cold water can hold higher O2 concentration, gets more saline as well (collects salt that has left the water that froze at the poles) and becomes dense (bc it’s cold + salty) and sinks to the bottom
Explain how the world’s surface waters and deep ocean are connected through the global conveyor belt, and give examples of why this is important to consider when studying marine organisms.
surface water at the poles sinks and moves O2 to the bottom of the ocean but ALSO nutrients and CO2 and other stuff!
deep water gets brought up, usually by ekman transport, bringing nutrients from the bottom back up
