Term
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Definition
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Term
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Definition
| drive horizontal movements |
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Definition
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Term
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Definition
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Term
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Definition
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Term
| atmospheric circulation is driven by |
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Definition
| variations in surface heating by the sun |
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Term
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Definition
-latitude
-reflectivity (albedo)
-seasons |
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Term
| characteristics of sinking air at the surface |
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Definition
-high pressure zone
-divergence
-dry: arctic/polar or sub-tropical |
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Term
| characteristics of rising air at the surface |
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Definition
-low pressure zone
-convergence
-wet: temperate/sub-polar or tropical |
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Term
| Why does the real world deviate from the atmospheric cell model? |
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Definition
-the tilt of the earth's axis: the latitude of the area with the most heating changes seasonally
-variations in land topography and albedo
-land-sea contrasts |
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Term
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Definition
-formed by the balance cetween wind stress and the Coriolis force
-extends to ~100 m deep (mixed layer depth)
-surface current at 45 degrees (or less) to the right of the wind (NH)
-Ekman transport is 90 degrees to the right of the wind (NH) |
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Term
| western boundary currents |
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Definition
-warm currents (North Atlantic: Gulf Stream, North Pacific: Kurishio)
-narrow (100-200 km)
-fast (between 40 and 120 km/day)
-deep (extending to 1000 m below the ocean surface) |
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Term
| Eastern boundary currents |
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Definition
-cold currents (N. Atlantic: Canary, N. Pacific: California)
-broad and diffuse
-shallow
-slow (between 3 and 7 km/day) |
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Term
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Definition
-Gulf Stream
-Kurishio
-Canary
-California
-N. and S. equatorial currents
-West wind drift (Antarctic Circumpolar Current)
-East wind drift
-Equatorial counter current |
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Term
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Definition
-major winds around highs and lows drive gyres
-major winds drive upwelling
-upwelling of cool, nutrient-rich water results in high biological productivity |
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Term
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Definition
-density-driven circulation
-thermo=temperature
-haline=salinity |
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Term
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Definition
-occurs where surface water becomes so dense that it sinks
-surface water needs to be very cold and salty (in order to sink) |
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Term
| normal weather conditions |
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Definition
-Walker circulation strong: trades blow E to W, thermocline shallow in E, upwelling of cold water in E, E to W temperature gradient reinforces trade winds
-Southern Oscillation Index positive |
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Term
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Definition
-Walker circulation weak or gone: trades very weak or reversed, thermocline deep in E, upwelling of warm water in E, sea level rises in E, E to W temperature gradient reduced or gone
-Southern Oscillation Index negative |
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Term
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Definition
-Walker circulation stronger than normal
-Southern Oscillation Index very positive |
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Term
| climactic effects of el nino |
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Definition
-drought in southern Africa, southern India, Sri Lanka, Philippines, Indonesia, Australia, S. Peru, W. Bolivia, Mexico, Central America
-heavy rains and flooding in Bolivia, Ecuador, N. Peru, Cuba, U.S. Gulf States
-hurricanes in Tahiti, Hawaii |
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Term
| three factors determine the amount of energy in a wave |
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Definition
-wind speed
-duration: length of time the wind blows in one direction
-fetch: distance over which the wind blows in one direction |
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Term
| as waves approach shore (water shoals) |
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Definition
-wave speed decreases
-wavelength decreases
-wave height decreases
-wave steepness increases (H/L)
-waves break (surf zone): d=1.28H |
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Term
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Definition
-interference
-reflection
-diffraction
-refraction |
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Term
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Definition
| -deep-water waves: d>L/2, group speed= 1/2 phase speed -shallow-water waves: d |
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Term
| how much has the temperature of the earth increased? |
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Definition
| 0.6 degrees Celsius over the last 100 years |
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Term
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Definition
-resultant forces= differences between centripetal and gravitational forces (tractive force)
-tide-generating forces are horizontal components |
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Term
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Definition
-small horizontal forces push seawater into two bulges on opposite sides of the earth
-one bulge faces the moon |
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Term
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Definition
-the amount of time it takes for the moon to orbit the earth (24 hours, 50 minutes)
-high tides are 12 hours, 25 minutes apart, occur twice in a lunar day |
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Term
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Definition
-diurnal
-semidiurnal
-mixed |
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Term
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Definition
-flood current
-ebb current |
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Term
| how do we know about past temperature? |
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Definition
-tree rings
-coral
-ocean sediments (composition of sediments, N. Pachyderma, O18 enriched/depleted)
-ice cores (atmospheric composition, O18 enriched/depleted) |
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Term
| things that affect climate |
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Definition
-insolation
-tectonics
-volcanism
-composition of the atmosphere
-albedo
-ocean circulation |
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Term
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Definition
-ice albedo feedback
-changes N Atlantic circulation |
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Term
| sea ice-albedo feedback (aerosols) |
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Definition
| -aerosols increase, which leads to surface cooling (because aerosols reflect the sun's radiation), so the sea ice increases and albedo increases, which leads to more surface cooling |
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Term
| sea ice-albedo feedback (greenhouse gases) |
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Definition
| -GHGs increase, which leads to surface warming, which leads to sea ice decreasing, so albedo decreases which leads to surface warming |
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Term
| N. Atlantic deep water formation |
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Definition
-weak or non-existent today
-Antarctic bottom water penetrated into the N. Atlantic in glacial times |
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Term
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Definition
| the presence of left-coiling foraminifera N. Pachyderma indicate the deep southward invasion of polar water during Heinrich events and the drop in salinities indicated by the 18O experiments was probably significant enough to temporarily shut down thermohaline circulation in the N. Atlantic |
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Term
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Definition
-"natural" sources of large climate change exist
-potent climate feedback exist
-changes in ocean ciculation can impact global climate
-some large limate changes are accompanied by GHG changes, some are not
-today's temperatures are higher than the last 1,000 years, and possibly the last 100,000 years |
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