Quiz 1 Flashcards
Basic goal is to obtain rigorous and systematic description of the World Ocean, sufficiently quantitative to permit us to predict its behavior in the
future with some certainty
Physical oceanography
studies fluid motions on rotating sphere
Geophysical Fluid Dynamics
surveys and describes (in the form of charts) physical properties of
the ocean relevant to navigation
Hydrography
studies Earth as a single system comprising many interacting
subsystems (spheres: atmosphere, lithosphere, cryosphere, ocean, etc)
Earth-systems science
- Observational, theory, lab experiments, numerical modeling
- Understanding the existing state of the ocean, e.g., nowcast/hindcast,
reanalysis - prediction
Major elements of PO
- in-situ sampling of seawater properties
- Weight called a messenger hits the lock and tips the bottle upside down. Valve closes the bottle keeping water sample inside
- Salinity was determined by titration of seawater sample
Nansen bottle
measuring conductivity and temperature as a function of depth in the ocean
CTD probe
yields velocity profile through the water
column (not just a single point measurement)
Acoustic Doppler Current Profiler (ADCP)
allows accurate current measurements from
moving research vessel
Satellite navigation (e.g., GPS)
-Poseidon
- Jason 1,2,3,
-Watchdog
Satellite Altimeters
If the Earth had a constant density and did not rotate around its axis, it would
have a shape of a…
Sphere (with constant radius)
If the rotating Earth had a constant density distribution, it would have a shape of an…
Ellipsoid (idealized)
takes into account non-uniform density distribution
Geoid
149.6×106 km
Average distance to sun
Earth is 3.4% farther from the Sun than at perihelion
aphelion
- Solar energy reaching the ocean surface is called…
- strongly depends on water vapor and clouds in the atmosphere
insolation
- Heat lost by the tropical ocean is the major source of heat needed to drive the atmospheric circulation
- The thermal energy transported by ocean currents is not steady, and significant changes in the transport, particularly in the Atlantic, may have been important for the development of the ice ages.
Key ideas
-as temperature increases, frequencies increase (shorter wavelengths)
- spectrum= range of frequency
Plank’s Law
Molecules of water vapor and carbon dioxide (CO2) absorb infrared (long-wave) radiation emitted by the Earth
major greenhouse gases in the atmosphere
- on avg incoming radiation and long-range radiation emitted into space are equal
- energy surplus in summer
Radiation balance
Poleward heat transfer is sustained by…
Atmospheric and oceanic circulation
- Intertropical Convergence Zone
-powerful clouds due to rising air (cumulonimbus= gets too warm)
ITCZ
where a wind blows from (northeasterly)
Atmospheric/ meteorological convention (wind)
where a current flows to (northeastward)
Marine/oceanographic convention (ocean currents):
Directions are measured in…
degrees starting from true north (0⁰ or 360⁰)
and counting clockwise
-meridional heat transport is sustained by atmospheric vortices in mid-lattitudes by…
-synoptic scale (100-1000 km) atmospheric systems; they are growing (or unstable) perturbations of the polar jet and they draw energy from the atmospheric polar front.
cyclones and anitcyclones
low pressure systems, where winds turn with the Earth’s rotation
Cyclones
high pressure systems, winds turn against the Earth’s rotation
Anti-cyclones
Solar radiation is greatest
On the equator (excessive heating and evaporation)
Hadley cells
- winds move away from equator towards poles
- energy is lost, air cools or towards equator atmospheric pressure decreases
Tradewinds
- move left along ITCZ, converge towards ITCZ
- increase atmospheric pressure
What is Earths rotation?
left in southern hemisphere and right in northern hemisphere
-high pressure near equator, low pressure in polar
- right direction (west to east)
Ferrel Cell (tropical)
-high pressure near ferrel cell, low pressure in poles
- left direction (east to west)
Polar cells
-Where does warm tropical air and polar air not blend
- found at gentle angle
Polar front
Rising air
Low pressure
Descending air
High pressure
- effects of large landmasses (eurasia)
- land warms much faster (ITCZ shifts) always moving up and down
- since there is more water in the southern hemisphere it is less effected
- high pressure over land in the winter
Real Large scale pattern
propagation of a signal (disturbance) with little or no net mass transport, often of periodic nature
Wave
continuous flow of seawater in certain direction (water mass moves from one place to another)
Current
chaotic rotational (that is, eddies or vortices) motions superimposed on general downstream trend (a mean
flow); they cause the transverse spreading of properties. In
many cases turbulence acts as a viscous force for the mean
flow. (Laminar regime as opposed to turbulent regime).
Turbulence
