Paleoclimatology/ Climate Change
How often does El Niño and La Niña occur?
About every 3-7 years
How is the fishing industry affected by El Niño in South America?
Because the water is warmer, there is less DO and nutrients for aquatic life to survive so there are less fish to catch
How does La Niña affect Australia?
Cool temperature, low pressure nearby creates floods
Why does Earth's axis wobble?
Earth is not a perfect sphere, it is thicker towards the equator
What does this melting/ freezing pattern tell us about the importance of slight changes in temperature?
Even a few degree change will warm up and melt the ice from below
T/F: Trees can grow in winter.
F: trees are dormant in winter
What can tree rings tell people about climate?
Floods, droughts, insect attacks, forest fires
How does ocean temperature during the Pliocene compare to the present?
Global climate was warming
What do thick tree rings indicate?
Grown in late spring/ summer, longer growing season, light colored, higher water content/ availability, grown in warmer climate
What do thin tree rings indicate?
Grown in late summer/ autumn, short growing season, dark colored, low water content and availability, grown in colder climate
Give examples of proxy data.
Historical data, sediments, pollen, corals, tree rings, ice cores (glaciers)
Based on changes seen in the sediment, describe how the ice sheet was behaving during the Pliocene?
Ice goes back and forth. It has frozen and melted over 60 times
The temperature from the 1800s until now indicate that temperature has ________ with the most dramatic increase after ____
Increased, 1920
Why does Earth have an elliptical orbit every 100,000 years?
Jupiter and Saturn's gravitational pull acting upon Earth
How has climate change affected the Midwest?
Longer growing seasons---> crop shock, Great Lakes heating up, Great Lakes have less ice, forests are receding into Canada, heat related heath risks, species loss, more extreme weather
How do active volcanoes impact climate?
Lots of active volcanoes add CO2 to the atmosphere which warms Earth over a long period of time. After the eruption, the ash and dust block the sun's rays from entering the atmosphere which cools Earth's temperatures.
What happens to climate when there is more water vapor in the atmosphere?
Low pressure which leads to rain and storms, air is more humid and hot because water vapor is a greenhouse gas, more sea ice melts
The mathematical relationship between proxy data and the climate record is used to create a ____.
Model
How does solar output affect temperature?
More solar output= more energy= higher temperatures
What happens to climate when CO2 levels are lower?
Overall temperatures are cooler, ice caps freeze more, sea levels drop
How do the Milankovitch cycles affect climate when the tilt is greater?
Poles are warmer, sea ice melts faster, tropics are cooler, seasonal differences are increased
What type of proxy data can indicate a change from a grassy environment to an environment rich in sage?
Pollen
What are 5 natural factors that cause climate change?
Position of continents, Milankovitch Cycles, Volcanic eruptions, ENSO Events, Variations in solar output
How have the collections of temperature data changed in the last 21 years?
Satellite measurements have been used to reconstruct global atmospheric temperatures
What do the climate models based on the Pliocene conditions in Antarctica predict for sea level rise?
Sea level rose 23 feet in the Pliocene. If this happened, coastal cities would be flooded within the next century
What happens to climate when sea ice melts?
Sea levels rise, temperatures are warmer, flooding of coastlines
How do Milankovitch cycles affect climate when the shape of the orbit is more circular?
Seasonal temperatures are different---> they are more constant
How do we know humans have caused some climate change?
Since the industrial revolution, CO2 and temperatures have increased rapidly due to excess burning of fossil fuels
What do the fossils and diatoms tell us about Antarctica?
Some of the fossils found were of animals that don't survive in cold climates/ water. Diatoms say the same thing, which helps tell what animals lived at what time
Corals allow climatologists to reconstruct the temperature by measuring what characteristics of the coral?
Species and isotopes of oxygen
Was the transition from warm to cold sudden or gradual? How long ago did it happen?
Sudden, 25 mya
How do sunspots differ from solar irradiance?
Sunspots are constant, solar irradiance CO2 and temperature fluctuate
What are impacts of global warming?
Temperatures have risen, ice caps have melted, sea levels are rising, CO2 levels are rising, increased number of forest fires, more hurricanes on east coast
What do geologists look at from the ocean floor sediments to tell the climate "story"?
Texture, color, contents
Temperature data has been collected as long ago as _________.
The 17th and 18th centuries
What is paleoclimatology?
The study of the climate that existed before humans began collecting instrumental measurements of weather
What key information is locked inside the shell of a foram?
They are from time when Antarctica was warm, and they help tell ocean temperatures using calcium from the shell
What is ANDRILL doing differently to study Antarctica's paleoclimate?
They drill through the ice and the ocean floor directly below to dig up rock layers and analyze them
How do scientists use glaciers to study paleoclimate?
They look for and analyze dust, air bubbles, or isotopes of oxygen because the air is "ancient" and untouched since the time the ice formed
Where is warm and cold ocean water for all Pacific Ocean Conditions?
Warm water is by Australia, cold water is by South America
How does El Niño affect Australia?
Warms temperature, high pressure nearby causes droughts
Normal Pacific Conditions:
•Air pressure over W. Pacific: low •Air pressure over E. Pacific: high •Surface wind around equator: east •Steep of thermocline: medium •Upwelling: normal
La Niña Pacific Conditions:
•cold water and air temperatures •Air pressure over W. Pacific: low •Air pressure over E. Pacific: high •Surface wind around equator: east •Steep of thermocline: steepest •Upwelling: increases •Australia: low pressure, wet and warm (flooding) •S. America: high pressure, cool and dry (drought) •S. America:
El Niño Pacific Conditions:
•warmer water and air temperatures •Air pressure over W. Pacific: high •Air pressure over E. Pacific: low •Surface wind around equator: west •Steep of thermocline: flat •Upwelling: none •Australia: high pressure, warm and dry (droughts) •S. America: low pressure, warm and wet (flooding)
How long does it take Earth to tilt 21.8° to 24.4°?
41,000 years
