5 Written questions
5 Matching questions
- how much has the average temperature of the earth increased over the last 100 years? would this increase have been greater or lesser at high latitudes?
- the climate system
- 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?
- how do we know what the concentration of atmospheric CO2 was during past glacial and interglacial cycles? where do these samples come from?
- what are some climate proxies?
- a 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
- b 1 degree Celsius rise in average temperature; increase greater at high latitudes- but the 10 warmest years have been during the past 15 years!
- c (1) seafloor sediments- contain remains of organisms that one lived near sea surface; useful recorders of worldwide climate change
(2) oxygen isotope analysis- based on precise measurement of the ratio bt 2 isotopes of oxygen; O^16 is most common and the heavier O^18: O^18/O^16 ratio in shells of microorganisms- past temperatures
(3) climate change recorded in glacial ice
(4) tree rings- archives of environmental history
(5)fossil pollen, corals, historical data
- d in ice, O18 increases relative to O16 during warm intervals. IN forarms, O18 decreases relative to O16 during warm intervals. Ice cores go back more than 400,000 years and record oxygen isotopes (T), atmospheric CO2 and methane in trapped air bubbles. The O isotope record form forarms "mirrors" that from glacial ice.
- e includes atmosphere, hydrosphere, geosphere, biosphere and cryosphere; these interact and involve exchanges of energy and moisture among the spheres- resulting in temperature and precipitation patterns (climate) around the globe
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
- heavy isotope increases relative to light isotope at cooler temperatures (O18/O16 goes up).
- weather refers to the state of the atmosphere at a given time and place; climate is a description of aggregate weather conditions based on observations over many decades; climate is often defined as "average weather"
5 True/False questions
what has a higher albedo, ice or land? → 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;
what is the composition of foraminifera shells (or tests)? → 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
what is albedo? → forms at ~ 20 - 30 km above Earth's surface, and is a protective layer that helps to filter out UV radiation by absorbing some of its energy. Life on planet Earth needs this because too much UV at Earth's surface (where we all live) can be harmful to cell function.
what causes air masses to move from place to place? → ice
How do CO2 levels today compare with those of the last 400,000 years? → 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