Biophysical Interactions by aZQK8Zp

VIEWS: 118 PAGES: 46

									Biophysical Interactions
            Atmosphere
            Hydrosphere
             Lithosphere
              Biosphere
  Case study – Murray Darling Basin
           The four spheres
• Define the
  following:
-Atmosphere
-Hydrosphere
-Lithosphere
-Biosphere
              The Atmosphere
• The transparent,
   odourless mass of air
   surrounding the
   Earth.
• It is made up of the
-troposphere
-stratosphere
-mesosphere
-thermosphere
                      Troposphere
• The Troposphere is the
  lowest layer of the
  atmosphere and measures
  about 12 km.
• It contains over 75 percent
  of all the atmosphere's gases
  and vast quantities of water
  and dust. As the sun heats
  the ground, it keeps this
  thick mixture churning.
• The weather is caused by
  these churnings of the mass.
• The troposphere is normally
  warmest at ground level and
  cools higher up where it
  reaches its upper boundary.
                       Stratosphere
• The Stratosphere extends from
  the tropopause up to its
  boundary (the Stratopause),50
  km above the Earth's surface.
• In this layer there is 19 percent
  of the atmosphere's gases and it
  contains little water vapour.
• Compared to the troposphere it is
  calm in this layer. The
  movements of the gases are
  slow. Within the stratosphere is
  the ozone layer, a band of ozone
  gas, that absorbs harmful
  ultraviolet rays of the sun.
                        Mesosphere
• The mesosphere is the next layer
  above the stratopause and
  extends to its upper boundary
  (the Mesopause), at 80 km above
  the ground.
• The gases in the mesosphere are
  too thin to absorb much of the
  sun's heat.
• Although the air is still thick
  enough to slow down meteorites
  hurtling into the atmosphere.
  They burn up, leaving fiery trails
  in the night sky.
• The temperatures in the
  mesosphere drop to -120 ºC) at
  the mesopause.
                Thermosphere
• The Thermosphere is the
  layer above the
  mesopause. The gases of
  the thermosphere are
  even thinner than those
  in the mesosphere, but
  they absorb ultraviolet
  light from the sun.
• Because of this, the
  temperatures rise to
  2,000 ºC at the top.
• This is at a height of 700
  km of the earth's surface.
                Composition
• What is the
  composition of
  the Earth’s
  atmosphere?
Composition
             Pressure systems
• List the
  characteristics of
  low pressure
  systems:
         Low pressure systems
•   Ascending air
•   Strong winds
•   Chance of rain
•   Clockwise (Sth Hemi)
•   Anticlockwise (Nth
    Hemi)
•   Most intense events
    are cyclones and
    tornadoes
        High pressure systems
• List the
  characteristics
  of high
  pressure
  systems
         High pressure systems
•   Fine weather
•   Calm conditions
•   Descending air
•   Clockwise (Nth Hemi)
•   Anticlockwise (Sth
    Hemi)
                    Air mass
• A body of air that has
    been affected by a
    large area of the
    Earth’s surface, such
    as an ocean or
    continent, is known
    as an air mass.
•   A front is where two
    air masses meet
                    Fronts
• What is the difference
  between a warm and
  cold front?
                 Warm fronts
• Warm air mass on the
    move
•   Clashes with and rises
    above the cold air
    mass
•   Results in rainfall
•   Labeled with bumps
                   Cold fronts
• Cold air mass on the
    move
•   Clashes with and
    pushes up the warm
    air mass
•   Results in rainfall and
    falling temperatures
•   Labeled with spikes
           Synoptic charts
• What can we
 read from a
 synoptic
 chart?
               Synoptic charts
•   Wind direction
•   Wind speed
•   Air pressure (hPa)
•   Air masses
•   Cold / warm fronts
•   Rainfall
•   Air temperatures
         Summer conditions
• Highs in
  southern
  Australia –
  drier
• Lows in
  Northern
  Australia – wet
  monsoon
  season
          Winter conditions
• Draw what would
 be expected for
 typical winter
 conditions.
      World pattern of climate
• What factors
  determine the
  world pattern of
  climate?
              Climatic factors
• 1. Solar radiation
• 2. Revolution of the
    Earth around the sun
•   3. Composition of the
    atmosphere
•   4. Distribution of
    continents and oceans
•   5. Topography
          Insolation variations
• Equatorial
  areas receive
  more direct
  solar radiation
  than polar
  areas.
 Earth’s revolution and rotation
• Tilting influences
  the seasons and
  temperature
  changes.
Composition of the atmosphere
• CO2 and water
    vapour help to
    regulate temperatures
    – the natural
    greenhouse effect.
•   Ave temps would be -
    18 degrees Celsius if
    the greenhouse effect
    did not exist.
      Distribution of continents and
                  oceans
• Warm ocean currents
    have high rates of
    evaporation and
    precipitation.
•   The cold currents
    produce little
    evaporation and
    precipitation - hence
    a factor in desert
    formation.
                 Topography
• Orographic rainfall
    can be produced by
    mountain ranges.
•   Moist climates are
    found on the
    windward side, while
    deserts / semi-arid
    regions are located on
    the leeward side.
              Microclimates
• What differences
  would you find
  between rural and
  urban areas?
                 Microclimates
         Urban                   Rural
High temps             Lower temps
More pollution         Less pollution
Higher humidity and    Less humidity and
rainfall               rainfall
Less sunshine          More sunshine
Weaker winds           Stronger winds
                     Aspect
• How can aspect
 determine climate
 in an area?
    Aspect induced microclimates
• Sth hemisphere –
    more sunlight on
    north facing slopes.
    Opposite in the Nth
    hemisphere.
•   This determines moist
    / dry slopes as well as
    bushfire risk and
    vegetation types.
     Human interactions with the
            atmosphere
• What are the
  different ways
  humans interact
  with the
  atmosphere?
                 Interactions
•   Urban air quality
•   Acid rain
•   Greenhouse gases
•   Ozone depletion
                   Air pollution
• Causes 1,400 lung
    related deaths in
    Sydney each year –
    more than car
    accidents.
•   However technology
    is improving –
    unleaded, diesel,
    ethanol in petrol, etc.
               Problem areas
• List some cities that
  have a reputation for
  serious air pollution.
                          Acid rain
• Sulfur dioxide and nitrogen
  oxide emissions from power
  plants form acids in the
  atmosphere that fall to earth
  as rain, fog, snow or dry
  particles.
• This acid rain is often carried
  hundreds of miles by the wind.
  Acid rain damages forests and
  causes lakes and streams to
  become acidic, killing the fish.
• Acid rain also damages
  buildings, historical
  monuments and even cars.
Acid rain
Acid rain
                 Ozone depletion
• Ozone partially filters
    ultraviolet radiation – UV-
    B radiation approx 30km
    above the Earth
•   Causes:
•   CFCs in fridges, air
    conditioners, etc.
•   Strategies have reduced
    CFCs considerably.
           Ozone depletion
• Effects:
• Ecosystem damage –
 eg Antarctica:
 phytoplankton is
 reduced from
 increased UV– affects
 the krill and the rest
 of the food web.

								
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