Transcript Bio 126 Climate and Weather

Ecology and the Biosphere
Chapter 52
Earth from the moon
Ecology
Ecology is the study of Distribution and
Abundance of organisms over time.
 Distribution is where we naturally find /
found an organism
 Abundance is how many individuals are
/ were counted at the study sites
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Fig. 52-2
Organismal
ecology
Population
ecology
Community
ecology
Ecosystem
ecology
Landscape
ecology
Global
ecology
Ecological levels
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Populations include all the members of one
species in a given area and time.
Species include all of the potentially
interbreeding populations.
Community includes all of the different
species (plants, animals, fungi, etc.) living in
the area
Ecosystem includes the Biotic and Physical
components of the environment
Landscape- Interactions between connected
ecosystems
Biosphere is world –wide issues, like Global
warming, and pollution
Climate
Determines what plants can grow there
 Two major factors of climate:
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– Temperature (warm to cold)
– Precipitation (moisture – wet to dry)
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Position on globe determines climate
Temperature
Simple gradient from warm to cold by
increasing latitude
 Solar intensity greatest and warmer at
equator (0o)
o
 Less intense and cooler at poles (90 ).
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Solar radiation
Solar radiation around the Globe
Solar radiation around the Globe
Precipitation
Alternating bands of wet and dry areas
along a latitudinal gradient
 Wet at equator 00, and 600 N / S
 Dry at 300, and 900 poles
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– Poles are frozen deserts
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Caused by formation of Hadley Cells
Hadley Cells
Air rises (00, 600) due to warming of
surface.
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as the air rises it becomes less dense
and cooler, dropping water as rain.
Air falls (300, 900 poles)
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air becomes compressed, and heats. It
absorbs moisture and falls as dry air.
Global air circulation, precipitation, and winds: Hadley cells
Convection Currents
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Global air
circulation is
affected by the
properties of air
water, and land.
Figure 5-5
Global Air Circulation
Hadley cell
West Coast Latitudes
Dry : nearer 300
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San Diego=32.5; LA= 34;
Sta. Barbara= 34.5
Santa Cruz =37, SF 37.75;
Eureka= 40.75
Wetter nearing 600:
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Portland= 45.5; Seattle= 47.5
Juneau= 58; Anchorage = 61
Hadley - Ferrel cells
Coriolis Effect
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Global air
circulation is
affected by the
rotation of the
earth on its axis.
Figure 5-4
Prevailing winds
These Hadley cell wind currents move
North or South
 The spinning of the earth makes it seem
like they come at an angle.
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– In CA our winds, storms usually come from
the south west.
– Our Rains often bring warmer weather
Global Trade Wind Patterns
Ocean currents
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Prevailing winds cause ocean waters to
move in the prevailing direction.
Northern Pacific flows clockwise
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Sea level 4 feet higher in Asia
Water flows from Alaska southwards along
our coast
Near shore upwelling brings cold, nutrient
rich water up along our shore
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Very high productivity of tidal areas
Ocean Currents
Upwelling
Wind from the north starts surface ocean
water moving
c. Deep, cold water
moves up to replace
water moving west
Earth's rotational force deflects moving water westward
Seasons
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Caused by tilting of earth on its
rotational axis.
– Intensity of sunlight varies.
– Most extreme at poles
– Little change at equator.
Seasons
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Tilting of earth moves solar equator.
Effectively moves solar 300 dry zone
north in summer
The wet belt moves farther south
giving us wet winters
Causes of Seasons
Biomes
Major vegetation types that also
determine the animal community
present.
 Determined mostly by climate
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– Soil also important factor
Common California Biomes
Dry to Wet
Desert - driest
 Chaparral – shrubs with fire cycle
 Grasslands – no trees, all grass
 Savanna – widely spaced trees in grass
 Woodland – open canopy
 Forest – closed canopy, wettest
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A climograph for some major kinds of ecosystems (biomes) in North America
Biomes
Major Biomes
Patterns of distribution in the biosphere
Coniferous forest, Lady Bird Grove (top left), Sequoias (right), rain
forest (bottom left)
Temperate deciduous forest, Great Smokey Mountains National Park
Tropical forests
Savanna
Desert. Organ Pipe State Park (top), Joshua Tree National Park (bottom left),
Death Valley (bottom right)
Temperate grassland- Prairie
Tundra. Denali National Park (left), reindeer (right)
Rain shadow
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Precipitation increases as storms are
pushed up over mountains.
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accordingly rain becomes snow
As air moves up slope in the Sierras it
cools 3-5 degrees per 1,000 ft.
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This is the same effect as moving 300 miles
farther north !
Causes deserts in Nevada
Most islands with mountains have wet
and dry sides
Rainshadow
Rainshadow
Biotic Zonation of Sierras
Summer Fog
Summer Fog
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Inland air warms quickly. This rising air, pulls in
coastal air.
Marine air is pulled inland by this draw in the
Central valley – causing summer winds over the
low passes (Altamont)
Cold water off CA. coast cools incoming warm,
moist ocean air- causing condensation.
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Essential for ranges of Coast Redwoods,
relic pines and cypress species .
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Can add up to 10 inches of summer precipitation in
some areas.
FOG HEAVEN / The sun will come out tomorrow. Or maybe not. It's summer in the city, and
that means gray skies.
What causes fog. Chronicle Graphic
Central Valley Smog
: weblog.rudayday.com/archives/2005_08.html
Smog moves up into Sierras
Temperature Inversion layers
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dense air flows downhill and collects in low spots,
valleys. Great Central valley is an example.
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This dense air may be blocked by hills etc. from warmer
winds which blow over the top of dense air, leaving it
alone.
Dense tule fog may form for days.
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Inversion layer (cold air higher up) also traps
pollutants.
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Mexico City problems
Reno, Tahoe now ban fireplaces.
Often “burn off” in summer but leave the haze of
phytochemical smog behind.
Ocean Zones
Intertidal – species rich zone on rocks
between high and low tides levels.
 Photic – upper sunlit layers where
phytoplankton (producers) live
 Neritic – productive zone over
Continental Shelf
 Oceanic - Open Ocean, nutrient poor
low productivity
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