Chapter 20 (exam three)
27 Cards in this Set
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weather
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the day-to-day state of the atmosphere with respect to temperature, precipitation, wind, cloudiness, pressure, etc.
variations occur on annual cycle (season)
generally controlled by regional changes in atmosphere temperature and moisture conditions
Can locally controlled by geogr…
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climate
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the average prevailing weather conditions of a region throughout the year, averaged over a series of years
Variations occur on much longer cycles (decades to tens of thousands of years)
Controlled by long-term changes in the atmosphere, hydrosphere, cryosphere, geosphere, and biosph…
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Geosphere
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all the solid rock material, sediment, and molten rock from the surface down to the core
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Atmosphere
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envelope of gases held to Earth by gravity, extending 100s of km upward
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Hydrosphere
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all liquid water at the surface (rivers, lakes, oceans, etc.) as well as groundwater
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Cryosphere
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all solid ice in the form of glaciers, snowcaps, sea ice, permafrost, etc
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Biosphere
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all living organism on planet Earth
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Anthroposphere
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the parts of the environment that are influenced or modified by human activity
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proxy data
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geologic record shows how global climate has changed throughout time
Widespread glacial deposits tell us about ice ages
Coal beds tell us about warm, tropical conditions
Limestones formed by coral reef environments tell us about warm, shallow seas
Evaporites tells us about ari…
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Seafloor Sediments
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contain fossils that give us give us indication of warm vs. cold water conditions
Foraminifera- very sensitive to changing temperatures
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oxygen isotopes
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18 O (8 p and 8 n) versus 16 O (8 p and 10 n) rations in marine fossils
The lighter 16O will evaporate more readily than 18O and become incorporated into atmospheric moisture
Both will form in CaCO3 shells and skeletons of marine organisms
High 18O = cold
Low 18O = Hot
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corals
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exhibit growth rings similar to trees, contain oxygen isotopes
good estimate of water temperature
They build their skeletons out of CaCo³ from sea water
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ice core records
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air bubbles, pollen, dust, volcanic ash in addition to snowfall amounts
Air bubbles trap paleo-atmosphere
composition of paleo-atmosphere (due to gases and such)
dust from meteorites
Photosynthetic ice algae: cryophiles
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pollen
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show vegetation changes in an area
dependent on temperature, moisture, altitude, latitude
incorporated into sediment or ice by wind or water
can determine which species of plants were present
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historical documents
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written records of events
year without a summer (1816 Mt. Tambora erruption in 1815)
First frost of the year
When crops are ready to harvest
Spring thaw
Annual flood levels
Major droughts
Major blizzards
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Atmosphere compostion
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Nitrogen - 78%
Oxygen - 21%
Argon - 1%
Carbon Dioxide - 398 ppm
all others include: neon, helium, methane, krypton, hydrogen
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factors that can change absorption or reflection of solar radiation
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cloud cover
ice cover
vegetation
volcanic output
greenhouse gases
sea level
aerosols
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albedo
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The percentage of energy reflected back into space
dark materials absorb more heat
lighter materials reflect heat energy
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positive feedback loop
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components amplify each other resulting in runaway effect
example: snowball earth
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negative feedback loop
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components mute each other resulting in equilibrium
example: clouds and air temperature
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greenhouse gases
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gases in the atmosphere that absorb and radiate heat energy from the sun
These include water vapor and clouds, CO², methane, N²O, and Ozone
Without GHGs, the Earth would be too cold to support life as we know it
GHGs in the atmosphere absorb that radiation keeping that heat energ…
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tectonic plate positions
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equator vs. poles
Changes oceanic circulation & heat transfer
Changes albedo & potential for glaciation
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orbital cycles
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Eccentricity, obliquity, precession affect the distribution of solar energy on the earth’s surface
Milankovitch cycles - The cycles correspond to major stages as seen from ice core and foraminifera oxygen isotope data over the past million years
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volcanic activity
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ash, dust, volcanic gases
This can reflect solar radiation back into space causing short-term global cooling until the ash and dust settle
Periods of abnormally high volcanic activity may result in global warming as more CO2 is emitted
Deccan Traps, India
Siberian Traps, Russi…
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solar activity and sunspots
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widely debated hypotheses that sunspot cycles are linked to temperature and precipitation variations
Possible, but no concrete evidence to support either.
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anthropogenic
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relating to, or resulting from the influence of human beings on nature
altering climate back to 12,000 years ago, with the Neolithic agricultural revolution
clearing forests, domestication of animals, burning wood/fuels
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Industrial Revolution
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Began in the mid-1700s
Switch from burning wood to coal, petroleum, and natural gas
burning coal generates unwanted byproducts.. carbon dioxide, methane, nitrogen oxide, sulfur dioxide..
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Chapter 10