GEO-SCI 103: Exam 2
61 Cards in this Set
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Structure of water
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2 hydrogen atoms (1 proton 1 electron) and one oxygen atom (8 protons 8 neutrons 8 electrons)
-2 e filling inner orbit
-6 e filling outer orbit
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Asymmetrical distribution of electron charge
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H end more positive
O end more negative
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Hydrogen bond
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Relatively weak electrostatic forces between oppositely charged ends of adjacent water molecules"
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Energy in H bonds
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Energy*is*required*to*break*H*bonds,*and*energy*is*released*wh
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Water
(solid phase)
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-ice
-crystalline structure less dense than liquid water
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Water
(liquid phase)
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-liquid water more dense than ice
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Water
(gas phase)
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-vapor
-hight energy molecules with few h-bonds
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Water has a high...and is a good...
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-surface tension
-solvent
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The sun showers every square meter of the ocean with how much energy/second?
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1430 calories
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Surface area of the ocean
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The surface area of the"ocean"is"361"x"10^12""m2
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Mass of water in ocean
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"1.4"x"10^24"g."
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Latent heat
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–The amount of energy required to change the physical without changing the temperature
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Condensation/precipitation
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-h bonds reformed
-latent heat released to the atmosphere
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Evaporation
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-h bonds broken
-latent heat removed from the ocean
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Runoff
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Surface & subsurface waters
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Latent heat of fusion
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80 calories
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Latent heat of vaporization
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540 calories
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Latent heat of vaporization
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heat energy is required to break hydrogen bonds when ice melts (80 cal/g) and when water evaporates (540 cal/g)
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Latent heat of fusion
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heat energy is released to the atmosphere as hydrogen bonds form when water freezes (80 cal/g) and when water vapor condenses
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Hydrologic cycle
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redistributes heat around the planet by cycling water b/w the ocean, atmosphere, and land
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Sensible heat
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It takes 100 cal of heat to raise the temp of 1 gram of water from 0 to 100 degrees C
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Sublimination
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changing from a solid to a gas
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Latent
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present but not visible, in a hidden phase
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How can you determine the salt content of sea water?
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-evaporate it
-refractometer
-conductivity meter
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2 most common ions in seawater
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Na+
Cl-
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Sea Salts
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-Chloride 55%
-Sodium 30.6%
-Sulfate 7.7%
-Magnesium 3.7%
-Calcium 1.2%
-Potassium 1.1%
-Minor constituents 0.7%
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Where do salts (dissolved ions) come from?
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-rivers contain dissolved ions in low concentrations
-obtain these ions from the chemical breakdown of rocks on the continents
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Why is seawater not concentrated river water?
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-may be other sources of ions to the ocean
-ions may be leaving the ocean (sinks)
-concept of residence time
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Where else are chloride and sulfate common?
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volcanic gases and fluids
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Hydrothermal circulation at spreading centers
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chemical reactions b/w hot volcanic rocks and icy cold seawater
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Residence time
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-amount of component in seawater/rate of addition or removal of
that component
-elements/ions that have biogenic output often have low concentrations & residence times
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Sources of dissolved salts in seawater
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-chemical weathering of rocks
-volcanic emissions
-hydrothermal activity on the seafloor
-fluid flowing out of accretionary prisms
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Sinks for salts
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-biological recycling
-burial in sediments
-ionic exchange
-subduction
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Average ocean salinity
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35%
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Summary of ocean salinity
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-all naturally occurring elements are dissolved in seawater
-multiple sources of dissolved salts in seawater
-chemical composition of the ocean has remained relatively constant over time because input = output
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Solar footprint
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-low angle of incidence in the high latitudes creates large solar footprint (solar energy dispersed across a wide area)
-high angle of incidence creates small solar footprint (solar energy focused on narrow area of the Earth's surface)
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Radiation
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-hotter objects emit mostly shorter wavelength (UV and visible light)
-cooler objects emit mostly longer wavelength (infrared light)
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Net radiation
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difference between the radiant energy absorbed and the radiant energy emitted
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Gradients of temp & pressure across the globe...
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drive fluid motions that act to balance the unequal distribution of heat
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Avogadro's principle
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a fixed volume of gas at the same temp and pressure has the same # of molecules no matter what gas is in the container
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When is Earth closest to the sun?
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N. hemisphere winter
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Thermal stratification
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-mixed layer (near surface where temp is roughly that of surface water)
-thermocline (part of water column where temp decreases rapidly from the mixed layer temp to the much colder deep water temp)
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Seasonality in temperate waters
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-winter storms tend to be bigger than summer storms
-summer heating and less mixing by storms causes a seasonal thermocline at mid-latitudes
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Why is a permanent thermocline absent in polar regions?
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b/c surface waters and deep waters are very cold
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Seawater density is a function of...
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-temp and salinity
-colder = denser and saltier
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Sigma tee
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(density-1.000) X 1000
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Circumference of Earth at the equator
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24,000 miles
24 hrs to make rotation
24,000/24 = 1,000 mph
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Which way does the Earth rotate looking down from the North Pole?
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counter clock wise
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Which way does the Earth rotate looking up from the South Pole?
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clock wise
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Coriolis effect
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causes air masses and water masses to be deflected to the RIGHT in the N. HEMISPHERE and to the LEFT in the S. HEMISPHERE
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Hadley cell
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-thermal circulation consisting of rising air near the equator and sinking air towards the poles
-hadley cell only reaches to mid latitudes
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Weather
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day to day changes in the atmosphere
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Climate
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seasonal progression of weather in a particular region and its year to year characteristics averaged over decades
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Why do hurricanes originate near the equator?
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-low humid air = low pressure system = storms
- tracks curve b/c of Coriolis effect
-spin counter clock wise b/c air is directed into the low pressure system
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Isobars
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lines of equal pressure
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Air-sea frictional coupling
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-friction within water causes the surface layer to drag/push the layer below it
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Eckman spiral
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-when the Coriolis effect causes each layer of water to move slightly to the right (N. hemisphere) of the water layer moving above it
-surface current: ~45 degrees to prevailing wind
-net current direction: ~90 degrees to prevailing wind
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Upwelling & downwelling
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-upwelling- where water is divergent (moving apart)
-downwelling- where water is converging (piling up)
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Pressure gradient
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-with a height difference water wants to flow downhill
-deflected by Coriolis effect
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Geostrophic flow and western intensification
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-geostrophic flow causes a hill to form in subtropical gyres
-the center of the gyre is shifted to the west because of Earth's rotation
-western boundary currents are intensified
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How to build a gyre
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-sun emits short wave radiation
-air warmed by heat transfer from ocean rises and moves toward poles
-moving air deflected by Coriolis resulting in meal zonal wind patterns
-wind moves surface layer of ocean (Ekman transport)
-surface drift piles up water in western half of subtropica…
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GEO-SCI 103: Final Exam