Lecture 1 Flashcards
What is physical oceanography?
- it is the study of waves, tides and currents
- > also looks at ocean-atmosphere interactions
- > lastly looks at transmission of light and ssound in the ocean
What is chemical oceanography?
- studies chemical composition and properties of seawater
- > looks at dissolved solids and gasses in the ocean
- > finally looks at effects of pollutants
What is biological oceanography
- study of various oceaninc life-forms
- >their distribution and relationships to one another
What is a moore time series
- any permanent structure that a ship or instrumentations are attached to
- limited in spatial abilities but is vast in temporal ability
-goes from hourly to inter-annual measurements in time
What is remote sensing
- ability to use satellites to gain info about the ocean
- >high spatial but variable temporal
What is the temporal resolution and the spatial resolution of repeat trans-basin sections
-there is large spatial scale or less temporal resolution
Is there more data for salinity or temperature
- more data for temperature
- >if there is separation of seasons, the difference in data collection is more pronounced for salinity
How does the amount of ocean data differ from near surface to deep surface
-less data for deep surface
Does Argo have enhanced resolution
- yes there is enhanced resolution
- >Argo can also go down as far as 1000 metres
What processes are important in physical oceanography
- heat storage and transport in the oceans
- the exchange of heat with the atmosphere and the role of the ocean in the climate
- wind/thermal forcing of the surface mixed layer
- the wind-driven circulation
- the dynamics of ocean currents
- the formation of water types and masses
- the deep circulation
- equatorial dynamics and El Nino
- waves in the ocean
- > both surface and internal
- waves in shallow water and coastal processes
What processes are important in chemical oceanography
- control on the chemical composition in the ocean
- distribution and cycling of element in the ocean
- box models, mass balance and residence time
- air-sea gas exchange
- organic matter production, export, and re-mineralization
- remineralization and burial in sediments
- interaction of oceanic cycling of elements
- carbon cycle, carbon dioxide and climate
- marine pollutants
- behavior of isotopes and their use as tracers of past and present oceanographic and climate processes
What processes are important in biological oceanography
- chemical and physical factors influencing distribution patterns of lifeforms in the ocean
- food chain dynamics
- nutrient cycling and initial steps of chemical energy fixation
- primary production
- biological pump
- responses to the result of man’s activities in the oceans
What are the three things used to study oceans
-theory, observations and numerical models
Can the three things used to study oceans(theory, observation and numerical models) be used separately?
No
1) Ocean processes are non-linear and turbulent
- >so theories are simplified
2) Observations are sparse in time and place
- >so observations cannot be used to describe oceans
3)Numerical models are approximations of the real life system and can’t represent small scale processes
Describe the Earth’s oceans
1) Pacific
- >largest ocean
- >makes up about 1/3 of the Earth’s entire surface
- >all of Earth’s continents could fit with room left over
- >the deepest ocean and named due to its calm weather
2) Atlantic
- >half the size of the pacific
3)slightly smaller than the Atlantic
4) Arctic
- >world’s smallest and shallowest ocean
- >surrounded by land
- >influenced by large rivers draining into it
- >has a permanent layer of ice on the surface
5) Southern Ocean
- >opposite of the arctic ocean
Why is it more difficult to study the ocean? Name 5 reasons
1) Seeing through the ocean water
- >water is a more efficient absorber of electromagnetic radiation(including light) than the atmosphere is
- >r
2) Inaccessibility
- >we can’t breathe water
- >also average ocean depth is around 3800 metres versus an average height of 840 metres on land
- this means that most of the ocean is as remote from the sea surface as the top of the mountains from the land
3) Pressure
- ocean pressure increases at 1 atm every 10 metres of depth
- instruments and submersibles need to be designed to survive these great pressures
- >they are very expensive
4) Conductivity/Corrosion/Fouling
- seawater conducts electricity, causing short circuits to electrical equipment
- >special water tight housing is needed for electric items
- seawater is corrosive
- >meaning special metals are needed to avoid rust and corrosion
- marine organisms grow on items left in the water
- >fouling them
- >this causes difficulties for instruments with moving parts
5) Wave motion
- >the ocean surface is dynamic
- >this causes problems with working on a moving ship with heavy equipment
What are the three provinces for the ocean floor
1) Continental margins
- >shallow-water areas close to the continents
2) Deep-ocean Basins
- >deep-water areas farther from land
3) Mid-ocean Ridges
- >shallower areas near the middle of an ocean
How are mid-ocean ridges and deep-ocean basins created
- it is created by sea-floor spreading
- also created as continents split apart
- > new continental margins are formed
What are the two types of continental margins
1) Passive Margins
- >not close to any plate boundary
- >eg; east coast of US
2) Active Margins
- >associated with plate boundaries
- >eg; west coast of US
What are the four features of a Continental margin
1) Continental shelf
- >generally flat zone
- >extending from the shore beneath the ocean surface to a point at which a marked increase in slope angle occurs
2) Continental slope
- >below and beyond the shelf break
- >where deep ocean basins begin
- >total relief in this area is similar to that found in mountain ranges on land
3) Continental Rise
- >Transition zone between the continental margin and deep ocean floor
4) Abyssal plains
- >extend from the base of the continental rise into the deep-ocean basins
What are the two main marine province environments
1) Pelagic environment
- >ocean water itself
- >where drifters and swimmers live out their lives in complex food webs
2) Benthic environment
- >ocean bottom
- >where marine algae and animals that do not float or swim spend their lives
What two provinces can the Pelagic Provinces further be subdivided into?
1) Neratic Province
- >extends from shore seaward and includes all water less than 200 m
2) Oceanic Province
- >Seaward of neritic province
- >including depths of beyond 200 metres
What are the four sections of the Oceanic Province
1) Epipelagic
- >from the surface to 200 metres
2) Mesopelagic
- >from 200 metres to 1000 metres
3) Bathypelagic
- >from 1000 metres to 4000 metres
4) Abyssopelagic
- >below 4000 metres
What is the single most important factor in determining distribution of life in the oceans
-light is the single most important factor in determining distribution of life in the oceans
What are the 3 zones based on the availability of sunlight
1) Euphotic zone
- >extends from the surface to a depth where there is still enough light to support photosynthesis
- >around 100 metres
2) Disphotic zone
- >has a small measurable quantity of light
- >extends from the euphotic zone to where the light can no longer penetrate
3) Aphotic zone
- >no light
- >usually around 1000 metres
Is oxygen and nutrients abundant in surface water
- yes
- > because oxygen is abundant due to mixing with the atmosphere and plant photosynthesis
-nutrient content is low as they are consumed by algae
Describe the oxygen minimum layer
- at deeper depths
- > oxygen decreases as it is consumed by heterotrophic organisms
- > this consumption produces an oxygen minimum layer coinciding with a nutrient maximum
Are nutrients and oxygen in high levels below the oxygen minimum layer
- yes
- > because below the OML, nutrients and oxygen remain high as it is replenished with high oxygen cold water from polar regions
- > organic matter is remineralized at depth
