Term
| Why we know it was warm 100 million yr ago |
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Definition
Fossils from Warm adapted animals (dinosaurs & crocodiles) North of Arctic Circle and South of Antarctic Circle
•Fossils of Warm adapted Vegetation (broad leafed evergreen trees (breadfruit) much farther North and South than now
•Coral Reefs much farther from Equator than today |
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Term
| Rate of temperature rise at various levels of carbon dioxide |
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Definition
Slow Rise of Temperature at High levels of Carbon Dioxide
•Lack of snow and ice to provide positive feedback
•Saturation - Adding more carbon dioxide does not cause much more absorption |
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Term
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Definition
Sea floor spreading rate changes volume
•Continents Colliding
•Volcanic Plateaus
•Storage of sea water in Ice Sheets
•Thermal Expansion of water when heated |
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Term
| Thermal expansion of water |
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Definition
When water warms it expands
•When water cools it contracts
•Resulting in 7 m drop since Cretaceous |
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Term
| Extra weight of water pushes down on ocean floor |
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Definition
Adding more water to area of ocean adds weight
•Extra weight pushed down ocean floor
•This cancels ocean rise by up to 30%, especially for adding water from glaciers |
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Term
| Effects of sea level change on climate |
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Definition
| More maritime areas so more maritime climate (milder winters and cooler summers) |
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Term
Greenhouse to Ice Age
What caused cooling |
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Definition
| Changes in spreading rate |
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Term
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Definition
Increase in high-elevation terrain
•2. High terrain causes unusual amounts of rock fragmentation
•3. Fresh debris was exposed
•Not only in Himalayas but also in other mountain ranges |
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Term
| Opening of Drake’s Passage |
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Definition
Opening of Drake’s Passage
•20 – 25 M yr ago
•Allowed ocean currents to circle Antarctica
•This kept water there cold since none came from higher and warmer latitudes
•This keeps Antarctica cool so ice can form
•Temperature difference between ocean and land causes strong wind which also isolates air over Antarctica especially in winter |
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Term
| Closing of Isthmus of Panama |
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Definition
Closing of Isthmus of Panama Diverts warm water to North Atlantic
4 – 10 M yr ago
•Keeps warm water from Caribbean from flowing into the Pacific
•Keeps cool water off South America from flowing into the Caribbean
•Causes warm water in Atlantic to flow north adding heat off Western Europe melting sea ice and causing air to warm |
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Term
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Definition
warm winter, cold summer
feedbacks - reflectivity of ice, saltiness of water
conditions during ice ages |
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Term
| conditions during ice age |
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Definition
When ice growing
–ocean saltier (not freeze in winter)
–ocean warmer (fewer ice bergs & less cold runoff
–thus more evaporation to provide winter precipitation
–albedo of ice make it more difficult to melt in summer
•When ice melting
–water from melt is fresh so ocean freezes in winter
–ocean cold from melt water so less evaporation
–less evaporation means less snowfall in winter
–albedo decreases in summer so more melting |
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Term
Milankovitch orbital variations (how each of these effect ice ages)
obliquity |
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Definition
Obliquity of Ecliptic - variation of tilt of earth relative to plane of orbit
–caused by torque of Sun & Moon on Earth
41,000 yr |
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Term
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Definition
Eccentricity of Earth’s orbit (ellipticity)
–caused by pull of Jupiter on Earth
22,000 yr |
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Term
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Definition
Precession of Equinoxes - date of Perihelion
–caused by torque of Sun & Moon on Earth
105,000 yr |
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Term
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Definition
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Term
| How cycles have changed in the last few million years |
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Definition
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Term
| Decreased carbon dioxide during glaciations (where it went to) |
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Definition
More CO2 dissolves in cold water
–Atmospheric CO2 drops by 9 ppm for oC cooling
–Total drop during Ice Age about 22 ppm
•CO2 dissolves easier in less salty water
–During Ice Age salinity increased about 1.2%
–Thus Atmospheric CO2 increased by about 11 ppm
Pollen suggests drier and less vegetation
–About 25% less so carbon not stored here
•If less CO2 in Atmosphere then less in near surface ocean (about 25%)
•Not enough time to exchange with rocks
•Thus must be in deep ocean |
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Term
Did Early farmers increase carbon dioxide and methane and how
Temperature changes in the last 1000 years – warm and cold periods |
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Definition
11000 years ago: Early peoples invent agriculture in Mesopotamia and China
•8000 years ago: Late Stone Age Europeans begin clearing forests to grow wheat, barley, peas and other nonindigenous crop plants
•7500 years ago: Humans adapt wild rice for cultivation
•5000 years ago: Farmers in the south of China begin flooding lowlands near rivers to grow rice |
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Term
| temperature changes in the last 1000 years |
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Definition
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Term
| Volcanoes – how they affect climate |
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Definition
| decreased radiation and temperature |
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Term
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Definition
less radiation. More radiation lately.
using tree rings |
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Term
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Definition
look at charts....11 year cycle
more sunspots. increase in temperature it seems |
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Term
| How we can measure solar output before instrumentation |
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Definition
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Term
Climate since 1800’s
Rebounding bedrock after ice left |
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Definition
| just know that the land rises causing the sea level to go down |
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Term
| Retreat of Mountain Glaciers |
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Definition
| a kilometer more 1700 and now -500 meters |
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Term
| Measuring changes in ice volume |
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Definition
| satelite ice elevation to bedrock elevation |
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Term
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Definition
0-20 cm 1900-2010
Ocean Thermal Expansion + 4
Mountain Glaciers + 5
Greenland and Antarctica + 2
All Factors +11 |
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Term
| Sub-surface ocean warming |
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Definition
| explosion. measuring sound wave with satellite |
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Term
| Arctic sea ice extent and other proof of global warming |
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Definition
general decline since 1979 in arctic sea ice
Increase of growing season in Alaska
Decrease in snow cover
over the northern hemisphere
Ice Cover Period on Lake Mendota decrease |
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Term
Greenhouse effect
absorption in infrared window |
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Definition
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Term
| greenhouse gases and their sources |
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Definition
CO2 - combustion, deforestation
•Methane - cattle, rice paddies, sewage
•CFC’s - refrigeration, foam making, cleaning, aerosol production (spray cans)
•Nitrous Oxide - fertilizer, combustion
•Surface Ozone - photochemical reactions (sources: 3/4 transportation, 1/4 power and industry) |
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Term
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Definition
Human Sulfate Emissions now Exceed Natural Emissions
effectively increasing the Earth's albedo
being largest downstream of large industrial areas.
Twomey effect increases albedo scattering with little air particles |
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Term
| feedback effects – positive and negative |
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Definition
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Term
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Definition
Positive (warming causes more warming)
–Warm water holds less carbon dioxide
–Glacial retreat reduces albedo
–Polar thawing releases methane held in permafrost
–Lower temperature gradient reduces deep sea current
–Warm water puts more water vapor in the atmosphere
–Reduced N-S temp gradient reduces deep sea mixing |
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Term
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Definition
Negative (warming causes cooling)
–Plants grow faster consuming more CO2
–More water vapor yields more clouds
–Deforestation makes tropics more reflective |
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Term
| how water amplifies effect of carbon dioxide |
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Definition
| more water vapor in clouds and snow and ice albedo |
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Term
| measurement of gases in ancient atmospheres |
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Definition
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Term
| conditions during climatic optimum and little climatic optimum |
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Definition
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Term
Future Climate Changes
Health effects |
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Definition
Health Effects of Global Warming
•Warming only
–Crime (violent and property)
–Heat Exhaustion and Stroke
–Japanese Encephalitis
–Legionnaires’ Disease
•Warming plus increased rain
–Asthma *
–Dengue
–Lyme Disease *
–Malaria *
–Rocky Mountain Spotted Fever
–Trypanosomiasis
–Yellow Fever
•* Linked to present Global Warming |
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Term
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Definition
Sea Level Rise (m at 2090-2099 relative to 1980-1999)
Case
Model-based range excluding future rapid dynamical changes in ice flow
B1 scenario
0.18 – 0.38
A1T scenario
0.20 – 0.45
B2 scenario
0.20 – 0.43
A1B scenario
0.21 – 0.48
A2 scenario
0.23 – 0.51
A1FI scenario
0.26 – 0.59 |
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Term
| Collapse of West Antarctic Ice Sheet |
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Definition
| the ice melts and then it will go into the water and raise the sea level. |
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Term
| accuracy of forecast models |
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Definition
| all follow a general upward trend increase |
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Term
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Definition
Zonal winds oscillate between easterly and
westerly in the tropical stratosphere
• Period about 26 months
• Winds propagate downward from upper
stratosphere at about 1 km/mo until they
reach the tropical troposphere. They then
weaken and the reverse winds start in the
upper stratosphere.
• Westerly descent more regular than easterly
• Easterly winds are about twice the
magnitude of the westerly winds |
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Term
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Definition
Influences of QBO
• Hurricanes and Typhoons more prevalent in
the western phase
• Tropical Cyclones in the Western Indian
Ocean are more prevalent in the eastern
phase |
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Term
| Pacific Decadal Oscillation (PDO) |
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Definition
Warm or Cool surface waters in the Pacific
Ocean North of 30° Latitude
• Shifts every 20-30 years
• Positive (Warm) phase is warm in Eastern
Pacific and cool in Western Pacific
• Negative (Cool) phase is cool in Eastern
Pacific and warm in Western Pacific |
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Term
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Definition
PDO Effect on ENSO
•During Warm phase of PDO, El Nino is Enhanced (early 1970’s to mid 1990’s)
•During Cool phase of PDO, La Nina is Enhanced (since 1990’s) |
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Term
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Definition
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Term
| During Warm Phase of PDO the following are Above average and are Below average during the Cold Phase |
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Definition
Air temperatures in NW North America from October - March
•Precipitation in Southern US and Mexico from October - March |
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Term
| The following are below average during the warm phase PDO and above average during the cold phase PDO |
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Definition
Air temperatures in SE US from October - March
•Precipitation in NW North America and Great Lakes Region from October - March
•NW North America spring time snow pack
•NW North America stream flow year round
•Flood risk in Pacific NW winter and spring |
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Term
| Atlantic Multidecadal Oscillation (AMO) |
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Definition
Atlantic Multidecadal Oscillation (AMO)
•Cycling of Atlantic Surface Water Temperature
•Most of North Atlantic is involved
•Period of 60 - 75 years
•Positive Warm Waters
•Negative Cool Waters
•Related to Thermohaline Circulation
•Decrease in Circulation decreases temperature |
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Term
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Definition
North Atlantic Oscillation (NAO)
•Seesaw in Pressure between Bermuda-Azores High and Icelandic Low
•Positive Phase - Azores High is Extra High and Icelandic Low is Lower than normal giving more Zonal Flow
•Negative Phase - Both High and Low are weaker and tend to give Meridional Flow
•They persist vertically throughout the Atmosphere |
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Term
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Definition
Positive Phase of NAO
•Iceland warmer and Greenland cooler due to stronger Icelandic Low circulation
•Dry in Southern Europe and Wet in Northern Europe in Winter due to Storm track shifting North
•Mild and Wet in New England since strong Westerlies discourage movement of cold air South |
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Term
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Definition
Negative Phase of NAO
•Wet in Southern Europe and Dry in Northern Europe in Winter due to Storm track shifting South
•More cP air with less precipitation over Eastern North America and Northern Europe as cold air pulled Southward by the strong ridge-to-trough sides of the Meridional Rossby Wave |
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Term
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Definition
Arctic Oscillation (AO)
•Seesaw pressure oscillation between North Polar Region and Midlatitudes
•Sometimes called the Annular Mode
•Positive (warm) phase - lower than normal pressure in Polar region and higher than normal pressure in Midlatitudes Negative (cold) phase is opposite pressure change
•The warm phase drives warm air north making the polar temperature gradient greater thus increasing the westerly circumpolar vortex aloft |
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Term
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Definition
Warm - Positive Phase of AO
•Strong circumpolar vortex keeps the cold air locked in Arctic keeping it warmer farther south in the Midlatitudes
•Storm track is thus farther north since temperature gradient farther north
• Subtropical locations warmer and dryer
•Stronger circumpolar vortex causes greater ozone depletion in the Arctic spring |
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Term
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Definition
Cold - Negative Phase of AO
•Circumpolar vortex is expanded pushing warm water away from polar regions making winds weaker and allowing cold air to move south pushing storm track south
•Subtropical locations are cooler and wetter
•Tropical trade winds are weakened |
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Term
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Definition
Pacific-North American Pattern (PNA)
•Relates Circulation Pattern over North Pacific with one over North America
•Positive PNA higher Heights near Hawaii and Intermountain Region of North America with lower Lows south of Aleutians and over SE US causing a ridge over the mountains and a trough over the Eastern US.
•Negative PNA is a more zonal flow or even a trough over the mountains |
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Term
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Definition
Positive PNA
•Circulation is more meridional than usual
•Higher winds and storms in Pacific Northwest
•Colder than normal in SE US
•Warmer than normal in NW US
•More rain in the Rockies
•Dry in SW US
•Less rain in Ohio and Mississippi Valleys |
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Term
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Definition
Negative PNA
•Circulation is more zonal than usual
•NW US is colder than normal
•SE US is relatively warm and wet
•More rain in Ohio and Mississippi Valleys
•More rain in SW US
•More precipitation in the NE US |
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