Miller Ch 6 - Climate, Weather, and Biodiversity
Starts off with a good news / bad news synopsis of connectedness of things on
Earth….for example, how winds are good for heat distribution and spreading
seeds, and how they are bad in that they spread pollutants from one part of the
planet to others.
Leads into the observation that wind and global circulation patterns are critical to
Earth climate, which in turn determines plant and animal life in major biomes
(think "life homes").
6-1 Weather and Climate - A brief introduction
diff between weather and climate….
 short term conditions of the troposphere are what we call weather
 long-term average of these weather conditions is what we call climate
Fig 6-2 - global map showing general climate zones
understanding global air circulation - this is the key to understanding climate
patterns
first, recognize that incoming solar radiation is concentrated near the equator,
striking Earth at almost 90o, and perpendicular through atmosphere. At the poles,
solar radiation strikes at much more glancing angle, and travels through much
more atmosphere.
Net result is that a circulation pattern is set up to move all the excess heat away
from the tropics and toward the equator.
Real pattern is a bit complicated, with 3 circulation cells per hemisphere.
Fig 6-4 - excellent figure showing the circulation cells
Want to learn more details?
Take a Physical Geography course from the NJCU Geoscience/Geography Dept
The way that warm air rises and cold air falls sets up precipitation patterns that
control climate and biomes….Fig 6-5
6-2 - Biomes: Climate and life on land
2 big factors control climate, and therefore control biomes:
 temperature
 precipitation
temp and precip set the stage for what can grow and live….grasses? trees?
Shrubs? Cactus?
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Fig 6-9 shows major biomes of world..they stretch laterally (East-West) and
coincide with climate zones (Fig 6-2), controlled by patterns of precip set up by
global circulation cells. Spend some time comparing figs 6-9 and 6-2
Note Fig 6-10 depiction of how biomes change with changing precip and
temperature (temp controlled mostly by distance from equator)
In general, you can classify Earth temperature into three major zones:
 tropical (hot)
 temperate (moderate)
 polar (cold)
similarly, break precipitation into three zones exemplified by type of vegetation:
 forest (high precip)
 grasses (moderate precip)
 desert (low precip)
these 6 factors can combine to yield Earth's biomes
fig 6-11 - note interesting phenomenon associated with increasing
elevation…climbing up a high mountain vertically from sea level causes you to go
through the same biomes that you would travel through on a trip form the equator
to either pole
6-3 desert and grassland biomes

desert definition is surprisingly simple: "an area where evaporation exceeds
precipitation" - this typically is about 10" of rain per year or less
tropical, temperate, and cold deserts are all possible
in desert biomes, 2 themes predominate:
"beat the heat"
"conserve water"
many creative strategies used to do both these things, including staying in the
shade during the day and coming out at night

grassland has bit more precip than the desert, such that grasses and a few
trees can grow, but it does not have enough precip to support large numbers
of trees
tropical, temperate, and polar grasslands exist (like deserts)
one type of tropical grassland is called savanna, found in Africa
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temperate grasslands may be prairies (US), pampas (S. Amer), veldt (Africa),
steppes (Europe)
polar grasslands are known as tundras
6-4 Forest and Mountain Biomes
forests have moderate to high annual precipitation, which supports trees
tropical, temperate, and polar (boreal) forests exist
tropical rain forest is one type of tropical forest, centered near equator
tree type is "broadleaf evergreen"
tropical deciduous is further away from equator, little less rain
temperate forests further away from equator, characterized by deciduous trees
that like warm summers, can handle cold winters, and like precipitation
evergreen (coniferous) boreal forest characterized by cold winters, short
summers….needles are short, adapted to handle cold and dry weather
6-5 Saltwater life zones
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