Card Set Information

2012-04-04 10:04:25
Mid term

Natural Hazrds
Show Answers:

  1. External energy
    • Short wave is a term used to describe radiant energy with wavelengths in the visible spectrum, near-ultraviolet (UV), and near-infrared (NIR) spectra
    • Long wave is the energy leaving the earth as infrared radiation at low energy
  2. Greenhouse effect
    • Related to long wave radiation
    • Keeps the planet livable
  3. Albedo
    • The reflectivity of a surface
    • Smooth, shiny, light colored
  4. Energy Transfer: Convection
    Warmer less dense material rises and cooler, denser material sinks- vertical
  5. Energy Transfer: Conduction
    Molecule to molecule transfer of heat
  6. Energy transfer: Advection
    The transfer of a property of the atmosphere, such as heat, cold, or humidity, by the horizontal movement of an air mass
  7. Humidity
    • Relative
    • Refers to the amount of water vapor in the air
    • Relative humidity: the amount of water in the atmosphere at a given temperature
  8. Adiabatic processes
    • A change in temperature of a mass without adding or subtracting and heat
    • Rising air expands and cools, sinking air contracts and warms
  9. Lapse rate
    • Dry adiabatic lapse rate – when the parcel temperature is higher than the dew point
    • Moist adiabatic lapse rate – when the parcel temperature is equal to the dew point
    • Lifting condensation level: the height at which the parcel temperature is equal to the dew point
    • LCL- lifting condensation level
  10. Atmosphere layers: Troposphere- Decrease. Where all weather occurs
    mostly heated by transfer of energy from the surface, so on average the lowest part of the troposphere is warmest and temperature decreases with altitude
  11. Atmosphere: Stratosphere- Increase, where ozone layer is
    Temperature increases with height due to increased absorption of ultraviolet radiation by the ozone layer, which restricts turbulence and mixing.
  12. Atmoshpere: Mesosphere- decrease
    It is the layer where most meteors burn up upon entering the atmosphere. Temperature decreases with height in the mesosphere
  13. Atmosphere: Thermosphere- Increase
    Temperature increases with height in the thermosphere from the mesopause up to the thermopause, then is constant with height
  14. Pressure
    • Sea level pressure: 1012.25 mb, or 101.3 kp
    • High pressure: think pushing down
    • Low pressure: think less push
  15. Coriolis effect
    • Right in the north, left in the south.
    • The effect of the Coriolis force is an apparent deflection of the path of an object that moves within a rotating coordinate system.
  16. Pressure belt
    Natural pressure belts across the globe
  17. Circulation cells
    • Rotation results in three cells
    • polar, ferrel, hadley
  18. Winds
    The flow of gases on a large scale. On Earth, wind consists of the bulk movement of air
  19. Air masses
    Air masses are relatively large bodies of air that are fairly horizontally uniform in characteristics.
  20. Fronts
    • is a boundary separating two masses of air of different densitiesfronts are depicted using various colored lines and symbols, depending on the type of front.
    • Cold: blue front with triangles facing toward the right
    • Warm: red front with half circles facing right
    • Stationary: red and blue front alternating with half circles facing left, triangles facing right (air masses arent moving)
    • Occluded: purple front alternating triangles and half circles facing right (fast cold front, catches slow cold front)
  21. Jet stream
    • fast flowing, narrow air currents found in the atmospheres of some planets, including Earth.
    • The main jet streams are located near the tropopause, the transition between the troposphere (where temperature decreases with altitude) and the stratosphere (where temperature increases with altitude)
  22. Ocean circulation
    Temperature and salinity
  23. Condensation nuclei
    Particles that is used by water to condense into liquid form from vapor
  24. Coalescence vs Bergeron feindisen
    • Coalescence:
    • Tropical regions
    • Large condensation nuclei (ex. water drop gets bigger and moves faster as it goes down a window)
    • Thickness of cloud impacts drop size
    • Warm clouds

    • Bergeron feindisen:
    • Middle and high latitudes= colder clouds
    • Have to have both below freezing and above freezing in the same cloud
  25. rain
    Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface.
  26. Sleet
    • Freezing before it hits the ground
    • Cold to warm then back to cold/freezing again before it hits the surface
  27. Freezing rain
    Snow at higher altitude, melts completely and refreezes on the surface or right above it
  28. Snow
    • Below freezing
    • a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material
  29. Hail
    • Formation of hail
    • Strong updrafts carry raindrops above the freezing line Strong downdrafts return frozen droplets to below the freezing line
    • Recirculation continues many times
  30. Lightning
    • Electrical charges separation between clouds and clouds and the ground
    • Top of cloud positive, bottom of cloud negative, ground positive
  31. Cloud-to-cloud
    Lightning discharges may occur between areas of cloud without contacting the ground. When it occurs between two separate clouds it is known as inter-cloud lightning
  32. Steps
    • Step 1: A step leader- stream of electrons taking the easiest path down through the air—don’t see
    • Step 2: May be more than one path (don’t see)
    • Step 3: Flow of positive charges goes upward “return stroke” – don’t see
    • Step 4: An arc sparks upward and downward flow connecting them- see illuminationo
    • Step 5: Circuit is completed with a flow of electrons re-illuminating the channel “dart leader”
  33. mid-latitude cyclones
    • Northern hemisphere cyclone around a low pressure system
    • Low pressure= counter clockwise
  34. Ways of thunderstorms forming
    • Tall, buoyant cumulus clouds of rising moist air. Lapse rate of 6-10C
    • Cumulus doesn’t mean thunderstorm out of it
    • When parcel rises or is warmer then the environment- unstable
    • Parcel sinks or stays the same place so its cooler then environment.
    • Stable, sunny and nice
  35. 3 common thunderstorm formations
    • Convection: Midwest
    • Orographic lifting: Move air mass over mountain
    • Frontal system: Can happen anywhere. Occluded or cold front
  36. Air mass
    • Most commonTropical locations
    • Mid-latitudes, late summer afternoon
  37. 3 stages of air
    • Early stage: warm humid air rising, then cool and condenses. If it continues to rise move to next stage
    • Mature stage: Ice crystals if below freezing. Pull with forces- down drift. Rises and condenses, drops fall. Updrafts continue, strong downdrafts operate
    • Dissipating stage: Downdraft dominant, cloud mass shrinks
  38. Supercell
    • Violent type forming with a large updraft or air
    • Tilt: storm increasing, can last 2 hours
    • Mesocyclone- create vortex of spinning air
    • Rain, hail, tornadoes
  39. Downburst:
    • Very localized column of sinking airHit the ground and spread out in circular motion.
    • EX: drop jar of spaghetti sauce and it explodes out everywhere
  40. Stages:
    • Contact stage: fastest wind speeds. Downdraft begins
    • Outburst stage: flow in all different directions. Moving from point of impacts. Curling effect after hits ground and
    • spreads out
    • Cushion stage: Friction slows surface winds. Winds slow down
  41. Downbursts and planes
    Shift in the winds in addition to the downward movement
  42. Derechos: Spanish for straight ahead
    Straight line of winds
  43. Dust storms
    Common in arid and semi-arid regions
  44. Tornado occurence
    • 70% great plains
    • 80% US
    • 20% everywhere else
  45. Formation
    • On a regional scale
    • Typically have some cold dry air that is sinking
    • Need to have a high level jet stream
    • Tilt= wind shear which will help with the rotation
    • Need these 3 pieces for tornado to occur:
    • Low- altitude, northward flow of tropical air
    • Mid-latitude, cold, dry air mass
    • High- altitude jet stream wind moving east
  46. Supercell- tornadoes
    • Large updraft, strong updraft, some downdraft
    • Thunderstorm needs to have large updraft to get tilted by wind sheer
    • Most tornadoes produces by supercells
  47. wall cloud
    • Form in supercell where updrafts are strongest (looks like it would be a ceiling cloud)
    • Tornadoes usually fall from these
    • Markedly lower cloud beneath the main mass of the mesocycle
  48. Outbreaks
    When conditions are correct for one tornado they are correct for multiple tornadoes
  49. Tornado "wannabees"
    • funnel clouds: no contact with ground, not a tornado
    • dust devils: don’t originate from clouds. surface up- can rotate up to 70mph
    • water spouts: formed from water being pulled into an updraft that then condenses. drops down over water
  50. Myths of tornadoes
    • Tornadoes all rotate the same way (counterclockwise usually) but changes depending where the thunderstorm comes from
    • Most tornadoes travel from southwest to northeast (most of the time, though not always)
    • Tornadoes will not cross rivers, roads, etc. Not controlled by the surface- it’ll follow the cloud
    • Most damage in tornadoes is due to the winds. Open windows and go to the southwest corner of the house
  51. Tornado safety
    • Go to the basement
    • Center of the building
    • Go to smallest room – bathroom or closet
    • In a car or in the open? If tornado is close stop the car and get low (in a ditch)
    • Drive perpendicular to tornado
  52. Stream profile
    • The steeper the slope (higher gradient) near stream source and flatter (lower gradient at the stream mouth)
    • Base level
  53. Equilibrium- discharge VS speed
    • Seeking the balance to reach equilibrium
    • Too much discharge will make it flow quickly
    • Erosion increases causes to slope to then decrease
    • Too much sediment: A stream full of a lot of sediment can cause the gradient to increase as it piles up
  54. Meandering stream – cutoffs
    • meander bend in a river is breached by a chute channel that connects the two closest parts of the bend.
    • flow abandons the meander and to continue straight downslope
  55. Braided
    A stream consisting of multiple small, shallow channels that divide and recombine numerous times forming a pattern resembling the strands of a braid
  56. Floodplains
    • Floors of streams during floods
    • a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls
    • experiences flooding during periods of high dischargemade by a meander eroding sideways as it travels downstream
  57. Frequency/probablity of flood
    • Larger the flood the longer the recurrence time
    • Can be used to estimate return time of a given size flood
  58. Flash floods
    • Occur quickly and dissipate quickly
    • Local thunderstorms
    • Cause most flood related deaths
  59. Regional floods
    • Water inundates and extensive region for weeks
    • Typically occur in low topography river valleys
  60. Birdfoot delta
    A delta with long, projecting distributary channels that branch outward like the toes or claws of a bird.
  61. Avulsion
    • the rapid abandonment of a river channel and the formation of a new river channel.
    • Avulsions occur as a result of channel slopes that are much lower than the slope that the river could travel if it took a new course
  62. Levees
    occurrences where levees play a role in the height of flood watershigher levees, higher river levelswhen levees get saturated weak spots are create and then the water is able to attack by erosion
  63. Social Response: structural response
    • Dams
    • levees
    • sandbags
    • widening, deepening, and removing debris
  64. Social response: non-structural response
    • Forecasting
    • Zoning and land use
    • Insurance
    • Presidential disaster declarations
  65. Dams, levees, sandbags
    • Dams: large reservoirs are created to lessen the threat of flooding. Flooding can occur due to fail or overtopping
    • Levees: opponents, proponents
    • Sand bags: build temporary levees out of filled sandbags
  66. Urbanization: hydrograph
    Steam fed by underground flow of rain so that is why there is a slow flood dissipation
  67. Channelization: make channels
    • Clear of debris
    • Deeper
    • Wider
    • Straighter
  68. Tides
    • Neap tide: Lowest tide of the month
    • Spring tide: Highest tide, and they all line up (sun in line)
  69. Gravity
    • Immediate power behind erosion
    • Gravitational pullcan happen quickly or very slowly
    • Friction and inertia play a role in slowing gravity
  70. creep
    Imperceptible downslope movement of the soil and upmost bedrock zones
  71. Internal vs external forces
    • External: Anything outside, water sun light.
    • Internal: Anything that changes the stability of the slope
  72. Role of water
    • Weight of water
    • Absorption (filling of pores in a solid)
    • Adsorption (binding of molecules or particles to a surface)
    • Ability to dissolve cement
    • Piping
    • Pore-water pressure
    • Water table
  73. Classification: Falls
    occur when elevated rock masses separate along joints
  74. Classification: slides
    • movement above one or more failure surfaces
    • Transitional slides or slumps
  75. Classification: Flows
    Flows: mass movements that behave like fluid