Download What pat see? What affe distributi climates?

October 08, 2013
Blue = tropical
Red/orange = dry
http://en.wikipedia.org/wiki/K%C3%B6ppen_climate_classification
Purple/blue green =
continental (moist, severe
winters)
Green = temperate
(moist, mild winters) Grey = polar
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October 08, 2013
Climate
• A region's long-term weather patterns.
> Weather = short term atmospheric
conditions (temperature, precipitation,
humidity, wind speed and direction, cloud
cover, pressure).
• 2 main factors characterizes different climates:
average temperature and average precipitation
• What causes different climates?
October 08, 2013
Uneven heating of earth's surface by the sun (distance
from equator)
Cold
Intermediate
temperatures
Hot
Intermediate
temperatures
Cold
http://www.zo.utexas.edu/faculty/sjasper/images/50.11.gif
October 08, 2013
Seasons (tilt of earth's axis)
October 08, 2013
Global air circulation:
1. Uneven heating of
earth --> Convection
2. Rotation of earth on
axis --> Coriolis effects
-In Northern
Hemisphere: Things get
deflected to right.
-In Southern
Hemisphere: Things get
deflected to left.
http://serc.carleton.edu/earthlabs/climate/5.html
Convection + Coriolis effects --> Global wind patterns
that distribute heat and moisture (prevailing winds)
October 08, 2013
Global air circulation: Convection
Convection is the distribution of heat by the
movement of masses of fluids (liquid or gas).
October 08, 2013
Global air circulation: Convection
Uneven heating of earth's surface
results in three convection cells.
Hadley cell-explains distribution of
tropical rain forests and deserts
• Air rises at the equator (most sun)
– Air rising = low pressure
*Air moves
from low to
high pressure
October 08, 2013
Global air circulation: Convection
Uneven heating of earth's surface
results in three convection cells.
Hadley cell-explains distribution of
tropical rain forests and deserts
*Air moves
from low to
high pressure
• Air rises at the equator (most sun)
– Air rising = low pressure
• As air rises and cools, water
condenses and precipitates (rains a
lot over the equator)
• Air gets "pushed" north and south
from the equator
• Cool air falls, is compressed, and
warms.
– Air falling = high pressure
• Warm dry air over land = low
precipitation, takes moisture from
surface --> Deserts!
October 08, 2013
Global air circulation: Coriolis effect
http://serc.carleton.edu/earthlabs/climate/5.html
http://nsidc.org/cryosphere/arctic-meteorology/factors_affecting_climate_weather.html
October 08, 2013
Global Air Circulation
Convection cells + coriolis effect = global wind
patterns
polar easterlies
prevailing westerlies
trade winds
*Winds are named
by their origin
http://cas.umkc.edu/geosciences/env-sci/module4/weblab4.htm
October 08, 2013
Ocean Currents
Oceans absorb heat from the air (especially in tropic
regions)
Uneven heating
differences in density
warm and cold ocean currents
**Redistribute heat from uneven heating of sun
October 08, 2013
Ocean Currents
Uneven heating
differences in density
warm and cold ocean currents
*Redistributes heat
from sun
Currents driven by winds, earth's rotation, temperature
difference (density gradient) + interrupted by
continents
-Clockwise in northern hemisphere
-Counterclockwise in southern hemisphere
October 08, 2013
Proximity to water
*Heat is absorbed and released more slowly by water
than by land*
Bodies of water moderate climate.
Sea breeze
Land breeze
http://www.nc-climate.ncsu.edu/edu/k12/.breezes
October 08, 2013
Topography (mountains)
Mountains interrupt the flow of prevailing surface winds.
-Windward side: Air is forced up the mountain. Air
expands, cools, and loses moisture as rain and snow.
-Leeward side: Air flows down mountain. Air sinks,
contracts, heats up, and the dry air mass draws moisture
out of plants and soil below. *Rain shadow effect
October 08, 2013
Elevation
Parallel changes in
vegetation type occur
when we travel from
the equator to the
poles, or from
lowlands to
mountaintops.
You can find
extremely cold
climates near the
equator at high
altitudes (Ex: Andes
mountains)
http://www.zo.utexas.edu/faculty/sjasper/images/f37.14.jpg
October 08, 2013
Other factors:
Monsoons--continents near warm oceans experience
heavy rains called monsoons. Intense heating of land
during summer creates low pressure air masses ->
draws moisture from ocean -> leads to heavy rainfall.
Human contribution:
-Microclimates
Concrete/asphalt absorb and hold more heat. Human
impact (vehicles, appliance use) release lots of heat and
pollutants.
Results in higher temperatures, lower wind speeds
(buildings block winds)
-Greenhouse effect
October 08, 2013
Biomes
The distribution of organisms is determined largely by
climate.
Different climates
support different
communities of
organisms.
October 08, 2013
Biomes are large terrestrial regions characterized by
similar climate, soil, plants, and animals.
-Biomes are not uniform. Just a general
characterization of an area.
List of biomes:
1. Desert (Tropical, temperate, cold)
2. Grasslands
> Tropical grasslands (savannas)
> Temperate grasslands
> Polar grasslands (tundra)
> Chapparral
3. Forests
> Tropical rain forest
> Temperate deciduous forests
> Evergreen coniferous forests
> Temperate rain forest
4. Mountain biomes
5. Polar Ice
October 08, 2013
Desert
• Evaporation > Precipitation
• 30% land surface
• Hot day, cold night
• Tropical desert--hot, dry. Few
plants. Rocks and sand
• Temperate desert--high
temperature in summer, low in
winter. More precipitation.
Drought resistant shrubs and
cacti/succulunts.
• Cold desert--cold winters, low
precipitation, sparse vegetaion
http://environment.nationalgeographic.com/environment/habitats/desert-map/
October 08, 2013
Desert
• *Organisms: beat the heat,
every drop of water counts
> Plants (stomata, water
storage, leaves, root
systems, life cycle)
> Animals
> Insects
> Reptiles (waste)
http://wc.pima.edu/~bfiero/tucsonecology/adaptations/adaptations_home.htm
http://www.desertusa.com/survive.html
http://wc.pima.edu/~bfiero/tucsonecology/adaptations/adaptations_home.htm
• Desert ecosystems are very fragile. Why?
Slow plant growth (water is a limiting factor)
Low species diversity (difficult to survive in desert)
Low nutrient cycling (low bacterial activity)
October 08, 2013
Grasslands and Chaparral
Distribution:
-interiors of
continents
-too moist for
deserts, too dry for
forests
http://environment.nationalgeographic.com/environment/habitats/grassland-map/
Characteristics:
-Seasonal drought
-Grazing by large herbivores
-Occasional fires
-Low average
precipitation
-Range in average
temperatures
October 08, 2013
Grasslands and Chaparral
Grasslands
• Tropical (savannas)
• Temperate
• Polar (tundra)
October 08, 2013
Grasslands:
-Tropical Grasslands/Savannas:
• Warm temp year-round
• alternating dry/wet seasons
• Drought + grazing + fire inhibit
growth of trees/bushes
• Animals: farsighted, fast,
stealthy.
> Grazing and browsing
hoofed animals
> migration
> specialized eating
• Plants: survive drought
• Human impact: rangeland,
overgrazing, trees for firewood
--> desert
http://www.mnh.si.edu/mammals/pages/where/africa/waterhole.htm
October 08, 2013
Grasslands:
-Temperate grasslands
• Cold winter, hot dry summer
• Drought + fire + grazing +
winds
• Fertile soil due to decomposition
of grasses + root systems
• Tall v. short grass
• Human impact: raise crops,
raise cattle, build towns/cities
October 08, 2013
Grasslands:
-Polar grasslands/Arctic tundra
("marshy plain")
• Low precipitation, mostly
snow
• Grasses, mosses, lichen,
dwarf shrubs --> spongy mat
• Growth in "summer" 6-8
weeks
• Permafrost
> waterlogged soil
> forms seasonal
wetlands, lakes,
marshes, bogs, ponds
• Organisms: insects,
migratory birds, *need to
survive cold
• Human impact: oil drilling,
mines, military bases
http://www.ucmp.berkeley.edu/exhibits/biomes/tundra.php
October 08, 2013
Why does the tundra have a fragile biome?
Short growing season + cold! (soil and
vegetation recover slowly)
October 08, 2013
Chaparral
Distribution: Borders deserts, coastal
Climate: longer, rainy winters, foggy
Vegetation: low-growing evergreen shrubs, small trees,
leaves that reduce evaporation
Fires! -> seeds sprout.
October 08, 2013
Forest Biomes
• Lots of precpitation to support trees
• Forest = trees + other vegetation
• 3 types
> Tropical
> Temperate
> Boreal (polar)
October 08, 2013
Forest Biomes
-Tropical rain forest
• Extremely diverse
ecosystem
• Plants: broadleaf
evergreen, huge trees
(buttresses), dense
canopy*, vines *NPP
http://www.blueplanetbiomes.org/rainforest.htm
http://www.ecolibrary.org/page/DP9018
October 08, 2013
Forest Biomes
-Tropical rain forest
• Stratification of
specialized plants
and animal niches
• Adaptation for
pollination
• Acidic, low nutrient
soil--nutrients
stored in biomass
(quick recycling),
not soil.
• Human impact:
logging, crops,
grazing, minerals
• Tropical dry forest
http://rainforest-australia.com/Pollination_and_flowers.htm
October 08, 2013
Forest Biomes
-Temperate deciduous forests
• moderate average temperature,
change with seasons
• long warm summer, cold
winters, abundant precipitation
• vegetation: broadleaf deciduous
trees, more plant life at ground
level, leaf litter
• animals: predators, deer, small
mammals
• Human impact: fragmentation or
loss of habitats, industrialization
and urbanization *most
disturbed
October 08, 2013
Forest Biomes
-Evergreen coniferous forests
(boreals, taigas)
• Subarctic--long dry, cold
winters, short cool summers
*variation in sunlight
• Vegetation: coniferous
evergreen trees (needle-shaped,
waxy leaves, low diversity, grow
fast in summer
• acidic, low nutrient soil
• Animals: bears, wolves, moose,
lynx, many burrowing rodent
species
• Muskegs (acidic bogs)
October 08, 2013
Temperate rain forest (coastal coniferous forest)
• rain and moisture from ocean fog
• moderate temperatures
• Evergreens, ferns, mosses
October 08, 2013
Mountain Biomes
Dramatic changes in altitude,
climate, soil, and vegetation
• Erosion (slopes) when
vegetation removed by
natural disturbance or
human
• Islands of biodiversity
• Forests, endemic species,
sanctuaries for animals
(people tend to not build
on mountains)
• Regulate climate--glacial
ice (freshwater), ice/snow
reflect solar radiation,
gradually release melting
ice, snow, and water
October 08, 2013
Human Impact
1. Humans use, waste, or destroy 10-55% of NPP
October 08, 2013
October 08, 2013