Mid Term Flashcards
(101 cards)
Would Earth be better off without the greenhouse effect?
No it would be around 15 o C (28 o F) colder, and much of Earth would be frozen.
Venus has an atmosphere with 96% CO 2 . Does Venus have a stronger or a weaker greenhouse effect than Earth does?
Much stronger.
In a stable climate, which one is larger: total incoming radiation, or total outgoing radiation (or are they the same?)
In a stable climate ingoing and outgoing radiation are the same.
In 2050 the UN launch a giant mirror to reflect 5% of Earth’s incoming sunlight back to space.
- What changes in the shortwave radiation budget?
- What changes in the longwave radiation budget?
There would be 5% less incoming shortwave radiation. Earth would start cooling. The outgoing longwave radiation is determined by the temperature of our planet. As the planet cools down, the outgoing longwave radiation also is reduced. Once ingoing and outgoing radiation are the same, the climate will stabilize.
Carbon has two stable isotopes: 13 C and 12 C
• Standard: Vienna PDB, 13 C/ 12 C = 0.0112
• Pre-industrial atmosphere: δ 13 C = -6.5‰
• Volcanic CO 2 : δ 13 C around -2‰ to -6‰
• Fossil fuel CO 2 : δ 13 C around -23 ‰ to -30‰
Is the atmosphere enriched or depleted relative to the
Vienna PDB standard?
Depleted
Carbon has two stable isotopes: 13 C and 12 C
• Standard: Vienna PDB, 13 C/ 12 C = 0.0112
• Pre-industrial atmosphere: δ 13 C = -6.5‰
• Volcanic CO 2 : δ 13 C around -2‰ to -6‰
• Fossil fuel CO 2 : δ 13 C around -23 ‰ to -30‰
Which of the two CO 2 source is isotopically lightest, and which one is isotopically heaviest?
Fossil fuel CO 2 is isotopically lightest, volcanic CO 2 is isotopically heavy
Carbon has two stable isotopes: 13 C and 12 C
• Standard: Vienna PDB, 13 C/ 12 C = 0.0112
• Pre-industrial atmosphere: δ 13 C = -6.5‰
• Volcanic CO 2 : δ 13 C around -2‰ to -6‰
• Fossil fuel CO 2 : δ 13 C around -23 ‰ to -30‰
How will the atmospheric δ 13 C change if we add volcanic CO 2 ? And fossil fuel CO 2 ?
Adding volcanic CO 2 will make the atmospheric δ 13 C more positive. In other words, the atmospheric CO 2 will start to look more like volcanic CO 2 . Adding fossil fuel CO 2 will make the δ 13 C of the atmosphere more negative.
Carbon has two stable isotopes: 13 C and 12 C
• Standard: Vienna PDB, 13 C/ 12 C = 0.0112
• Pre-industrial atmosphere: δ 13 C = -6.5‰
• Volcanic CO 2 : δ 13 C around -2‰ to -6‰
• Fossil fuel CO 2 : δ 13 C around -23 ‰ to -30‰
Think of a way to test the cause of the CO 2 rise.
Measuring carbon isotopes of CO 2 in ice cores shows that δ 13 C of CO2 has become more negative during the industrial revolution. This shows the CO 2 increase is due to human fossil fuel emissions.
President Carter used an electric blanket to regulate his temperature at night. The blanket has a controller to change the heat production of the blanket.
Is this control system a positive or a negative
feedback loop?
negative
Initial change -> Jimmy too warm -> Jimmy turns down blanket -> Blanket produces less heat -> Jump to Jimmy too warm -> ...
Mr. and Ms. Carter each have their own blanket. One time they accidentally switch their controllers (Mr. Carter controls Ms. Carter’s blanket and vice versa).
After the mix up, do they have a positive or
negative feedback loop?
Positive
Initial change -> Jimmy too warm -> Jimmy turns down blanket -> Rosalynn's blanket produces less heat -> Rosalynn is cold, turns up blanket -> Jimmy's blanket produces more heat -> Jump to Jimmy too warm -> ...
Water vapor is a powerful greenhouse gas, that traps outgoing longwave radiation.
If the climate warms, what will happen to the amount of water vapor in the atmosphere?
The amount of water vapor will increase
Water vapor is a powerful greenhouse gas, that traps outgoing longwave radiation.
Is this a positive or a negative feedback loop?
positive
Initial Change -> Climate Warms -> Increased atmospheric water vapor -> increased greenhouse trapping of radiation -> Climate Warms -> ...
The inner core of our planet is made up mainly of iron and nickel. Thinking of the mechanisms of nucleosynthesis, why are these elements so abundant?
These elements are the final stage of stellar
nucleosynthesis (= the production of new elements in
stars via nuclear fusion). As the stars burn up their fuel,
Iron and Nickel are left over because they cannot react
further.
Our own sun has elements heavier than iron and nickel inside of it. Where do these come from?
These are produced in earlier supernova explosions. Our solar system is composed of recycled elements from earlier solar systems.
Carbon-14 ( 14 C, or radiocarbon) has a half-life of 5,730 yr. It is continuously produced in the atmosphere by cosmic radiation.
An archeologist finds old human remains. Radiocarbon analysis shows that the 14 C content is 12.5% of the atmospheric value. How old are these bones (how many half-lives)?
These remains are 3 half-lives old. That means their age is 3x5730 = 17190 years
Carbon-14 ( 14 C, or radiocarbon) has a half-life of 5,730 yr. It is continuously produced in the atmosphere by cosmic radiation.
Fossil fuel reservoirs are typically more than 10 million years old. How much 14 C is there (approximately) in fossil fuel CO 2 emissions?
All the 14 C will have decayed, and so there is no 14 C left
Carbon-14 ( 14 C, or radiocarbon) has a half-life of 5,730 yr. It is continuously produced in the atmosphere by cosmic radiation.
By emitting fossil fuel CO 2 , how do we change the 14 C of the atmosphere?
The 14 C ratio of atmospheric CO 2 will be reduced, because we mix the atmospheric CO 2 (which has 14 C in it) with fossil fuel CO2 (which has no 14 C in it).
The line that separates the inner rocky planets from the outer gas/ice planets is sometimes called the snow line. Why is this an appropriate name?
In mountains, the snowline is the lowest elevation at which snow remains frozen. This line separates regions where water can condense, and where it cannot.
Asteroids and comets both orbit the sun. Asteroids are mostly made of rock, and comets of ice. Where do you think they formed in the early solar system?
Asteroids formed in the inner solar system, closer to the sun where ice does not condense. Comets formed in the outer solar system where it is colder, and ice does condense.
Why can the age of meteorites tell us something about the age of the Earth?
Because they formed at the same time in the history of the solar system. While rocks on earth have been reworked due to plate tectonics, the meteorites have not been altered. Meteorites are therefore better suited to precisely measure the age of the earth.
The average density of the moon is 3.3 g/cm 3, and the density of the Earth is 5.5 g/cm 3 .
After the collision, who ended up with a larger percentage of core materials from Earth and Theia? (Iron has a density around 7.9 g/cm 3 , and rock 2.7-3.4 g/cm 3 )
Earth ended up with more of the heavy iron, which is why it is more dense. Earth has a larger core than the moon does.
Asteroid Psyche is thought to be 90% Iron-Nickel, and 10% silicate rock.
What part of planet Earth has a similar composition to Psyche?
THE CORE!!!
Why are the elements Iron and Nickel relatively abundant in the solar system?
They represent the final stage of nuclear fusion in heavy stars. These elements are left over as they cannot react further.
Asteroid Psyche is thought to be 90% Iron-Nickel, and 10% silicate rock.
Do you think that Psyche underwent planetary differentiation. Why?
Yes, must have gone through differentiation, because the metals have been separated from the rocky materials, which occurs during planetary formation through the process of differentiation
