Geo 103- Natasha Dimova- Test 2
What are the gyres?
(5 gyres) circular loops of moving water 1. North= clockwise 2. South= Counterclockwise
Where do photosynthesis and respiration occur and how do they affect the distribution of O2 and CO2 in the water column?
- Photosynthesis uses dissolved CO2 and produces O2. - Respiration occurs throughout the water column using O2 and releasing CO2. - However in the deep ocean can not diffuse O2 in and diffuse CO2 out fast enough. - At the surface O2 is high because of the availability of atmospheric O2 and photosynthesis. - Surface CO2 contents are low due to photosynthesis and low atmospheric concentrations - Increased dissolved CO2 in cold polar waters
If you had 100 g of seawater, what percentage of the mass is due to Chloride (Cl-)?
55% of the 3.5% of salt sea water is Chlorine
During wave motion, is water being transported from one place to another?
no
Define height
the vertical distance between trough of a wave and the following crest
What are the three main ions in seawater?
1. Na- Sodium 2. Cl- Chlorine 3. So4- Sulfate
What percentage of the ocean water is affected by the surface water current?
10%
Graphs, charts, pictures need to look at
- wavelength - thermohaline circulation - el nino, el nina, and normal conditions - elkman photos - three cell model - single cell model
Why does increasing the CO2 in the atmosphere due to fossil fuel burning will result in acidic conditions in the ocean?
-As Carbon dioxide in the atmosphere increases it sinks to the ocean and dissolves in water creating carbonic acid which is bad for marine organisms - As CO2 increases in the atmosphere the PH decreased in the ocean and the ocean water becomes more acidic
Name at least two driving forces of waves
-wind -tectonic events -mass movement -gravitational forces
List (in the correct order) the different climatic zones around the globe.
1. Equatorial 2. Tropical 3. Subtropical 4. Temperate 5. Subpolar 6. Polar
What are the four generic names of the currents that compose each gyre and which is cold or warm
1. Equatorial Current= warm, strong 2. Western Boundary Current= warm, fast 3. Northern/ Southern Boundary Currents= warm 4. Eastern Boundary Currents= cold, slow
Name the main processes through which the water is exchanged in Nature (within the Earth's system).
1. Evaporation 2. Precipitation 3. Infiltration 4. Subsurface percolation 5. Runoff
Name two processes that change the amount of dissolved salts in seawater.
1. Evaporation (increase salinity) 2. Sea-ice formation (increase salinity) 3. Precipitation (decrease salinity) 4. Melting (decrease salinity)
What are the 5 Gyres?
1. North Pacific Gyres 2.South Pacific Gyres 3. North Atlantic Gyres 4. South Atlantic Gyres 5. Indian Ocean Gyres
Name the main processes that lead to decreasing the salinity in the ocean.
1. Runoff 2. Melting icebergs 3. Melting sea ice 4. Precipitation
Name the main processes that lead to increasing the salinity in the ocean.
1. Sea ice formation: salt exclusion- seawater freezes in the cold water 2. Evaporation
What are the factors affecting the physical dissolution of gasses (in general) in liquids?
1. Solubility of the gas in liquids 2. Temperature 3. Partial pressure of the gas above the solution
Name the main reservoirs of the Erath's hydrological cycle.
1. World Ocean 2. Ice caps/ glaciers/ snow 3. Groundwater/ soil moisture 4. Streams/lakes 5. Atmospheric water pressure
What is the percentage of seawater from the total amount of water on earth?
97%
Define Pycnocline
Abrupt change of density with depth
Define thermocline
Abrupt change of temperature with depth
Would you expect clear sky during an anticyclonic event? Why?
Anticyclonic- high pressure system, colder air, cold air doesn't hold moisture well, cold dry air Clear Skys
Define the term "chemical residence time"?
Average length of time a substance remains dissolved in seawater
Explain the single-cell convective cell model of air circulation.
Because of atmospheric circulations, there are five gyres. The size of the ocean, the temperature of the ocean, the temperature of the currents are dictated by where the currents come from. Red- comes from the equator (always warm) Blue- come from the poles (always cold) *Only need to know gulf stream
Explain the current flow direction (clockwise or counterclockwise) in the gyres in the Northern Hemisphere versus in the Southern Hemisphere.
Because of the Coriolis Effect, N/S act in opposite direction in the 2 Hemispheres
Why do we have so much dissolved CO2 in the seawater compared to the amount of CO2 in the atmosphere?
CO2 reacts with the water and makes this very stable bicarbonate molecule. Very little CO2 reacts to go back into the atmosphere because it just makes a lot of sense for it to go make this stable bicarbonate ion. Then, this whole idea of positive feedback happens, where the more you have dissolved the more this reaction tries to pull more from other places in the Earth's system.
Explain the processes of photosynthesis and respiration
Cellular respiration and photosynthesis are biological processes in which matter and energy flow through the biosphere. Photosynthesis converts carbon dioxide and water into oxygen and glucose. Cellular respiration converts oxygen and glucose into water and carbon dioxide. Water and carbon dioxide are byproducts and ATP is energy that is transformed from the process.
What makes air expand and rise above the ground surface?
Convection is the transfer of energy in the flow of a heated substance. Heated air near Earth's surface rises, expands, and starts to cool. When it cools below the temperature of surrounding air, it increases in density and sinks, creating a convection current
Compare cyclonic (low pressure) and anticyclonic flow (high pressure)
Cyclonic flow- (low pressure system) is counterclockwise in the northern hemisphere and clockwise in the southern hemisphere Anticyclonic flow- (high pressure system) is the opposite, is counterclockwise in the southern hemisphere and clockwise in the northern hemisphere
Why is the single-cell model not adequate to explain the atmospheric circulations on Earth?
Earth is a rotating planet, so we need to consider the Coriolis force in addition to the pressure gradient force. In the single-cell model, as upper level air flows from the equator toward the poles, it would be deflected by the Coriolis force. In the northern hemisphere, for example, this deflection would be toward the right resulting in a wind from west to east at upper levels. In this way, the air moving from the equator to the poles would never make it there because of the rotation of Earth. A different model is needed.
Why or why not do you expect to have high concentrations of nutrients in the deeper water column?
Deep water there is reparation, which puts nitrogen back into the water; more nutrients in deep waters b/c of deep water circulation
What is the Coriolis Effect?
Deflection of free moving masses due to the Earth's rotation
Explain the dipolar nature of the water molecule using its chemical structure.
Dipolar- have partial charge in both ends, negative O and partial positive Hs, in turn the molecules attract each other = hydrogen bonding, not super strong, but keeps molecules organized. Dipolar nature of water can dissolve a lot of things like salt (NaCl).
How are waves generated?
Disturbing Forces cause waves to form
Based on the diagram on slide I have in my lecture, the bottom currents have opposite direction to the surface current flow. Why? What is the velocity of these currents with depth?
Elkman spiral is caused from deeper waters deflecting right moving slower with increased density
If the water is not being transported, what is then transported and how?
Energy is being transported by the cyclic motion of particles in the ocean up/down back/forth around/around
What "drives" the surface ocean currents?
Equatorial upwelling
What is the Ekman spiral?
Explains the balance between friction and Coriolis effect and describes the direction and flow of surface waters at different depths
Why salinity at the equatorial areas decreases with depth whereas at the polar areas is the opposite?
First, salinity up to about 100m depth is all constant because of currents. These mix the ocean water here very well and so salinity is all distributed evenly. Sea ice formation extracts freshwater and leaves the salt behind. This is what causes salinity to increase with depth in polar areas.
How does the Coriolis Effect affect the atmospheric circulation?
Greatest effect at the poles; Least effect at the equator. This causes air masses and things in the northern hemisphere to be defected to the right and in the southern hemisphere to the the left.
What is the temperature of the Gulf Stream? Which gyre is it part of?
Gulf stream - warm, flows quickly, south to north
Write down the formation of carbonic acid and use the equations to answer the previous question.
H2CO3
Should we expect high or low sediment depositional rates as waves refract?
High sediment
Based on the three-cell model, where would you expect to have high-pressure zones on the Earth?
Horse latitudes (see slide 20; ch.6) - poles have low heat energy - cloudy skies
Is a hurricane a high-pressure system or a low-pressure system?
Hurricanes are a low pressure system
Which parameter (salt content versus temperature) affects more density of water?
In equatorial areas, the effect of temperature overwhelms the effect of dissolved ions. This makes the high salinity water less dense and it sits on top rather than sinking.
What is the shape of a PH profile of a typical water column?
In the water column, there would be a depth at the dotted line, CDD. The depth where it will survive as calcium bicarbonate at shallower depth or below the dotted line it will be precipitate.
Do you know if 2021 is El Nino or La Nina year?
La Nina
Explain this physical property of water: Cohesion
Molecules sticking together
Give examples of limiting nutrients.
Nitrogen and Phosphorus
In a deep water column, would you expect to "feel" the wave? Why (or why not)?
No, the wind is not affecting the water deeper in the ocean
We defined Chloride (Cl-) as a conservative element. Why?
Non-conservative element in seawater- all nutrients because they're taken by organisms so their residence time is very short. Conservative elements- have a very large residence time, not precipitated or participate in the biological or physical process so it just stays there
Explain El Nino and La Nina with regards to normal conditions?
Normal Conditions- air pressure is higher in the eastern pacific, strong southeast trade winds, pacific warm pool on the western side of the ocean, thermocline deeper on the western side, upwelling off thee coast of Peru.El Nino Conditions- High pressure in the eastern pacific weakens. Weaker trade winds, the warm pool migrates eastward, thermocline deeper in eastern pacific, downwelling, lower biological productivity (Peruvian fishing suffers)La Nina Conditions- Increased pressure difference across equatorial pacific, stronger trade winds, stronger upwelling in the east, shallower thermocline, cooler seawater, higher productivity.
Which gyre is the Gulf Stream part of?
North Atlantic Gyre
How is wave energy distributed from offshore (where the wave is generated) to inland?
Offshore waves have more energy than inland shallow wave waters
What is the unit for salinity?
PPT (parts per thousand)
Based on the three-cell model, where would you expect to have low-pressure zones?
Polar fronts & Equator (see slide 20; ch.6) - equator has more energy - lots of evaporation
What is hydrogen bonding?
Polarity means small negative charge at O and small positive charge at H. Attraction between positive and negative ends of water molecules to each other or ions
How do we measure the salinity of seawater?
Salinometer- measures waters electrical conductivity ( more dissolved substances increase conductivity)
Define halocline
Separates ocean layers of different salinity
Give an example of a non-conservative element.
Sodium Chloride if it's low concentration; Sulfate if its high concentration = high residence time.
Explain this physical property of water: High solubility of other chemicals in water
Solubility can be affected by temperature (for solids it tends to increase solubility and in gases it decreases solubility)
Why or why not do you expect to have high concentrations of nutrients in the upper water column?
Surface waters have low concentrations of nutrients b/c of photosynthesis
What do we mean when we say "the earth hydrological cycle is a closed system"?
The Earth doesn't gain/lose water. The water is continually being recycled around the globe in the hydrologic cycle.
What is the explanation for the seasons on Earth?
The Earth is tilts on an axis, so it receives different radiation creating four seasons.
Which part of the Earth receives the most amount of solar radiation?
The amount of solar heat depends on the seasonal orientation of the Earths axes to the sun
Describe the wave energy distribution within the water column
The energy transported by a wave is directly proportional to the square of the amplitude (height) of the wave
What is albedo?
The proportion of the incident light or radiation that is reflected by a surface, typically snow/ ice covered areas; the average for Earth is 30%
Explain sea and land breeze
The sea breeze blows from ocean to land- related to high and low pressure zones & heat capacity. Water has higher heat capacity, during the day the water heats up slower-cooler water, land heats quickly. Cooler air on the ocean and hotter air on top of the land site. Cold air blows from the ocean to the land during the day. During the night, the same thing, but water is still warm and the land cools very quickly- then wind blows from land to ocean- cool to warm.
What drives the air movement along the coastlines?
The temperature differences move the air along the coast line
Define calcium compensation depth (CCD)
The water depth at which the rate of supply of calcium carbonate from the surface is equal to the rate of dissolution. CCD is where all calcium deposits will dissolve below this depth which releases carbonate ions and buffers the ocean's pH.
Based on the distribution of high and low-pressure zone, which directions would you expect the winds to blow?
The winds to blow towards the equator. The wind is the driver of the currents and gyres.
Why the surface seawater salinity at the north pole is lower compared to the south pole?
There is more runoff in the north pole, which decreases salinity. In the south there is much less
If we increase the CO2 in the atmosphere, how this is going to affect the level of the CCD within the water column?
Too much CO2 could raise the CCD as it makes the oceans more acidic, it is placed in more shallow depths
Explain the building of high and low pressure within the ocean water column
Transferring water from the surface creates low pressure within the water column which in turn results in "lifting" water from the bottom closer to the surface
What is the average salinity of the global ocean?
Typical salinity is 35 ppt
What is the formation and flow directions of deep ocean water?
Vertical and Horizontal flow/motions
What is the result of wave refraction for the morphology of the coastline?
Wave refraction gradually erodes headlands and sediment from this accumulates in the bay
What is the main source of salt in the ocean?
Weathering and the erosion of the Earth's crust (minerals were dissolved from the land and salt was one of them)
Define trough
bottom of a wave where the water is drawn back
Explain this physical property of water: High Heat Capacity
seawater has a very high heat capacity, it's why the water doesn't boil at the equator; amount of energy that needs to be introduces to the system to change states (ex. liquid to gas)
What is the hydrologic cycle?
the cycle of water exchange between the atmosphere, land, and ocean
Define wavelength
the middle of one wave to the middle of the next
Explain this physical property of water: High Surface Tension
the property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules