5 Written questions
4 Matching questions
- how do we know what the concentration of atmospheric CO2 was during past glacial and interglacial cycles? where do these samples come from?
- how far back can we trace temperature and atmospheric CO2 concentration using ice core data?
- trophospheric ozone
- how far back in time can we trace climate using historical documents?
- a > 400,000 years
- b ...
- c ozone near the earth's surface (the troposphere is the lowest ~12 km of the atmosphere) - and affects us adversely when levels get to high. This is because ozone (O3) is a strong oxidizer. Tropospheric ozone is created from an interaction between sunlight and pollutants such as nitrous and sulfur oxides - in our area, most of these pollutants come from combustion in vehicles burning fossil fuels. But, a certain (regulated) amount is emitted from power plants as well. Ozone alerts (or Ozone action days) in Dallas are days when tropospheric ozone concentrations are higher than acceptable for good health. These are nearly always during the summer months.
- d changes in carbon dioxide and methane are linked to fluctuating temperatures. the cores also include atmospheric fallous such as wind-blown dust, volcanic ash and modern day pollution
5 Multiple choice questions
- plate tectonics, variations in earth's orbit involving shape, obliquity and precession, volcanic activity and changes in sun's output associated with sunspots
- every year, trees add a layer of new wood under the bark; characteristics of each tree ring such as size and density reflect the environmental conditions (especially climate); the age of the tree can be determined by counting the rings --> ring chronologies are used to reconstruct climate variations within a region for spans of thousands of years prior to human historical records
- tiny, often microscopic, liquid and solid particles that are suspended in the air. Aerosols act directly by reflecting sunlight back to space and indirectly by making clouds "brighter" reflectors
- by analyzing pollen from accurately dated sediments, it is possible to obtain high-resolution records of vegetational changes in an area because pollen and spores are parts of life cycles of many plants and are easily identifiable
- the hotter the radiating body, the shorter the wavelength of maximum raidation
5 True/False questions
what isotopes form what part of the foraminifera test composition can be used to tell us about past ice sheet volume changes, and ALSO about past changes in ocean water temperature? → foraminifera is a skeleton made of CaCO3 (same as calcite) oxygen isotope rations depend upon water temp; these tiny, single celled organisms are sensitive to even small fluctuations in temperature; seafloor sedimetns containing fossils such as this are useful recorders of climate change
can you figure out why O18 increases (relative to O16) in the tests of foraminifera during cold intervals, but decreases (relative to O16) during cold intervals in water samples from ice cores? → every year, trees add a layer of new wood under the bark; characteristics of each tree ring such as size and density reflect the environmental conditions (especially climate); the age of the tree can be determined by counting the rings --> ring chronologies are used to reconstruct climate variations within a region for spans of thousands of years prior to human historical records
negative-feedback mechanisms → positive feedbacks are changes that reinforce the initial change
ex: warmer surface temperatures can cause an increase in evaporation, which further increases temperature as the additional water vapor absorbs more radiation emitted by Earth
what was the purpose of the Ocean Drilling Program? → ...
what is the greenhouse effect? → the atmosphere warms the planet and makes Earth livable; the important role it plays in heating earth's surface is called the greenhouse effect: this energy heats the air and increases the rate at which it radiates energy, both out to space and back; think of short-wave UV coming in, long-wave radiation going back up from the surface as heat, these waves are absorbed by greenhouse gases, including CO2, methane, and others). We are most concerned about CO2 because we are adding it to the atmosphere in the greatest amounts, and it accumulates (does not dissipate for hundreds of years)owards Earth;