Download 7-2 How Does Climate Affect the Nature and Locations of

Climate and Terrestrial Biodiversity
Chapter 7
7-1 What Factors Influence Climate?
 Concept 7-1 An area's climate is determined
mostly by solar radiation, the earth’s rotation,
global patterns of air and water movement,
gases in the atmosphere, and the earth’s
surface features.
7-1 What Factors Influence Climate?
 Weather is a local area’s short-term physical
conditions such as temperature and precipitation.
 Climate is a region’s average weather conditions
over a long period of time.
“Climate is what we expect, weather is what we get.”
-- Mark Twain
7-1 What Factors Influence Climate?
 Climate varies from place to place because the
air circulation in the lower atmosphere due to:
1. Uneven heating of the earth’s surface by the sun
2. Rotation of the earth on its axis
3. Properties of air, water, and land
7-1 What Factors Influence Climate?
1. Uneven heating of Earth’s surface by the sun:
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Equator vs. poles – round planet
Earth’s tilt – 23.5º
Albedo – how strongly it reflects light
Insolation – solar radiation received
by a given area in a given time (kWh/m2/day)
7-1 What Factors Influence Climate?
7-1 What Factors Influence Climate?
2. Rotation of Earth on its axis:
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Rotation is FASTER at equator than poles…
causes the Coriolis Effect – the deflecting of
air masses by the rotation of the Earth
Also causes complex global air circulation
Wind belts produce ocean surface currents
7-1 What Factors Influence Climate?
If the Earth didn’t
rotate, we could
expect wind to flow
in the following
manner…
7-1 What Factors Influence Climate?
Instead it looks
like this…
7-1 What Factors Influence Climate?
3. Properties of air, water, and land:
•
Convection cells form due to
interaction between air/water/land
7-1 What Factors Influence Climate?
7-1 What Factors Influence Climate?
 Heat and moisture are
distributed over the earth’s
surface by vertical air
currents, which form six
giant convection cells at
different latitudes.
7-1 What Factors Influence Climate?
 Ocean Currents are caused by:
• Prevailing wind belts
• Earth’s rotation
 Ocean currents influence climate by distributing heat
from place to place.
 The temp. of the water affects the temp. of the air
7-1 What Factors Influence Climate?
Generalized Map of the Earth’s Current Climate Zones
7-1 What Factors Influence Climate?
 The Greenhouse effect keeps the entire planet
warmer than it would be without it
 Greenhouse gases:
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Water vapor – H2O
Carbon Dioxide – CO2
Methane – CH4
Nitrous Oxide – N2O
7-1 What Factors Influence Climate?
The Rain Shadow Effect
 Interactions between land and oceans and disruptions of
airflows by mountains and cities affect local climates.
 Microclimate – local and regional climates different than
the larger regional climate
7-2 How Does Climate Affect the Nature and
Locations of Biomes?
 Concept 7-2 Differences in average annual
precipitation and temperature lead to the
formation of tropical, temperate, and cold
deserts, grasslands, and forests, and largely
determine their locations.
7-2 How Does Climate Affect the Nature and
Locations of Biomes?
 Climate Affects Where Organisms Can Live
 Biomes – large terrestrial regions characterized
by similar climate, soil, plants, and animals
• Biomes vary by, and are determined by:
• Latitude and elevation
• Annual precipitation
• Temperature
7-2 How Does Climate Affect the Nature and
Locations of Biomes?
7-2 How Does Climate Affect the Nature and
Locations of Biomes?
Generalized Effects of Elevation and
Latitude on Climate and Biomes
7-2 How Does Climate Affect the Nature and
Locations of Biomes?
Average Precipitation and Average Temperature as Limiting Factors