Intro to Oceans

What are the three stratified layers of the ocean and by what are they defined?
Surface zone (also mixed layer), pycnocline, deep zone. Defined by density.
Which of the three Washington DC, England, or San Francisco has the warmest summer and why?
Washington DC, heat and moisture from the Gulf Stream.
What is the result of wind blowing water horizontally?
Water comes up to replace the displaced water- this is upwelling
Where is some of the most nutrient poor water and why?
In the open tropical ocean, strong layering isolates deep nutrient rich water
What effect does downwelling have on the climate?
No direct effect
What is Langmuir circulation?
Vortexes on the surface of the water (rarely disturbs ocean below 20 meters)
How often do the direction of the winds across the tropical Pacific reverse direction in the Southern Oscillation?
Irregular intervals of 3-8 years
How long does a typical El Nino last?
A year, although some have lasted more than three
How do ENSO events affect life around Peru?
The Peru current slows due to reversed flow of water reduces upwelling, reducing fish and seabirds.
Okay…there are now five layers of the ocean. What are all five?
Surface water, Central Water, Intermediate Water, Deep Water, Bottom water
What is the mixing and sinking process called?
jk caballing
Name the deep water masses.
Antarctic bottom water, north atlantic bottom deep water, Mediterranean deep water
Order the waves from smallest to biggest with typical wavelength.
Capillary (up to 1.72cm), wind wave (60-150m), seiche (large, variable), seismic sea (200km), tide (half earth’s circumference)
What are signs of El Nino?
– Weakening Trade
– Increased Sea Surface
Temperature in the
Eastern Equatorial Pacific
-positive Oceanic Nino Index of positive .5 or more
What are signs of El Nina?
– Increased Strength of
Trade Winds
– Cooler Sea Surface
Temperatures in the
Eastern Equatorial Pacific
– negative ONI -.5 or less
What is ONI?
Oceanic Nino Index- based on the sea surface temperature difference from El Nino average 3.4 region.
What makes an element conservative or nonconservative?
Elements that vary little in their profile are conservative. Non conservative means they change their redistribution faster than ocean mixing time of 1500 years
Why more O2
less Si, N, P, in deepest
water at 6 km
I don’t know……..
What are the 4 parts of the Air Sea Heat Budget?
Short wave (solar) in, long wave (blackbody, IR) out, sensible (due to T difference) in or out, latent heat (cooling due to evaporation) out
In what six seas does deep water form?
Sea of okthosk, labrador, greenland and norwegian, mediterranean sea, wedell sea, ross sea
What are two equations for a deep water wave?
C=L/T, C=sqrt(gL/2pi) or 1.251(sqrtL)
What’s the equation for shallow water waves?
sqrt(g)d, 3.1d
Which of the two major oceans is older and what does that imply?
The Pacific is older, it’s saturation horizon is shallower
What classifies a deep water wave?
depth is greater than half it’s length
what makes a shallow water wave?
depth is less than its length/20
What waves are affected by the Coriolis effect?
All waves with periods over 20 seconds
Why are south bay tides greater than golden gate tides?
basin resonance
what is the disturbing force of a seiche?
change in atmospheric pressure, storm surge
what are three disturbing forces of tsunamis?
faulting of sea floor, volcanic eruption, landslide
Are most tides diurnal or semidiurnal and what does it mean?
Most tides are semidiurnal. They peak twice in a day
When do waves start to break?
when depth is shallower than wavelength/2
What is a drowned river mouth?
type of estuary formed when sea level rose into river mouths
Estuary formed when glaciers eroded u shaped trophs below sea level, deep w/steep sides
Bar built
barrier islands/spit limit water intrusion. these are shallow, and mixed by wind
estuary formed by faulting or subsidence leads to coastal indentation
Describe mixing scenario salt wedge
caused by rapid freshwater flow, tidal influence low to mod.
describe well mixed
slow freshwater flow, mod to high tidal influence. tidal turbalence, mixes well
partially mixed
rapid freshwater flow, mod to high tidal influence. freshwater comes in goes a little on top
rapid freshwater, little tidal influence
How old are the oldest sediments?
200 million ya
What are five important factors in forming sediments?
tectonic setting, proximity to continents, rate of production/delivery of material, rate of dissolution, chemical precipitation rates
How do we learn about sediments?
sounding weights, echo sounders
At what size does sedimentation occur?
sand and smaller
at what temperature does biotic production of CAco3 occur?
5 degree celsius or higher
what affects caco3 solubility and how does it affect it?
it increases with decreasing t and increasing p
How does respiration affect the pH of the deep sea?
Lowers the pH
What does CCCD stand for?
Calcium Carbonate Compensation Depth where rate of delivery equals rate of dissolution
What are the two forms of CaCo3?
Calcite and aragonite
Is calcium conservative or nonconservative?
where are calcite and aragonite supersaturated?
calcite= shallower than 700m
aragonite= shallower than 500m
What are examples of siliceous organisms?
Diatoms and radiolaria
What are some calcareous organisms and what do their shells tell us?
Coccolithophores, foraminifera and pteropods. Shells show temperature and chemical conditions of water. climate recorders.