Logical Reasoning

PT120 · S1 · Q18 In the troposphere, the lowest

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In the troposphere, the lowest level of the earth’s atmosphere, the temperature decreases as one progresses straight upward.

Statements

mathematical comparisons

In the troposphere (lowest level of atmosphere), higher you rise, colder it gets Top of Troposphere = -50° poles to -85° equator

Then stratosphere starts (next level of atmosphere), higher you rise, warmer it gets

Stratosphere is warmed by ozone, which generates heat when it absorbs UV.

Evaluate

There's a lot to chew on here. We essentially have two different Inference patterns:

1. the mathematical comparison

temp decreasing Bottom ----> Top Troposphere Troposphere

temp increasing Bottom ----> Top Stratosphere Stratosphere

2. the causal relationship

Sun sends ---> ozone ----> heat is out UV rays absorbs generated

Goal

It's hard to predict where they're going, but it will probably test the mathematical comparison or the causal relationship.

18.

If the statements above are true, which one of the following must also be true?

  1. The troposphere over the poles

    Out of Scope

    Out of Scope: thickness Opposite, if anything We don't ever discuss the thickness of the troposphere, but if we were to guess, we'd guess the opposite of this. After all, ground temperatures near the Equator are probably usually around 25° C. But by the top of the troposphere above the Equator, they're -85°C. So going from ground level to the top of the troposphere is a 110° decrease at the equator. Meanwhile, ground temps near the poles are closer to 0° C. By the top of the troposphere, they're -55° C. So going from ground to top of troposphere is a 55° decrease at the poles. Since the temperature decreased by twice as many degrees going from ground to top of troposphere at the equator, we'd guess that the troposphere was thicker over the equator.

    2% picked this

  2. It is warmer at the

    Unknown Comparison

    This paragraph didn't give us any way to compare different parts of the Earth to each other, at a given layer of the atmosphere, other than at the top of the troposphere. There, we know how the poles compare to the equator. But we don't know how they compare at the top of the troposphere. At the bottom of the stratosphere, the equator is -85 and the poles are -55, but we don't know how much each of those temperatures will increase by the time we get to the top of the stratosphere.

    18% picked this

  3. The temperature in the middle

    Unknown Comparison

    This paragraph didn't give us any way to compare different parts of the Earth to each other, at a given layer of the atmosphere, other than at the top of the troposphere. There, we know how the poles compare to the equator. But we don't know how they compare at the middle of the stratosphere. At the bottom of the stratosphere, the equator is -85 and the poles are -55, but we don't know how much each of those temperatures will increase by the time we get to the middle of the stratosphere. We know both temps are increasing, but we don't know that they're increasing at the same rate. It could be that the stratosphere over the Equator warms up at a faster rate as you go straight up than it does over the poles. (especially given that ozone being hit by sunlight is what warms the stratosphere, and there's more direct sunlight at the equator than at the poles)

    8% picked this

  4. Correct

    The temperature at any point

    Why this is right

    This is just testing the mathematical comparison we got from the 2nd and 3rd sentences. Let's suppose we're at the equator with a ground temp of 27°C. temp decreasing Bottom ----> Top Troposphere Troposphere 27°C -85°C temp increasing Bottom ----> Top Stratosphere Stratosphere -85°C higher than -85° The top of the troposphere = the bottom of stratosphere. And "as one progresses straight upward through the stratosphere", the temperature increases.

    Skill tested: Must be True · how this choice captures the argument's function is the move to repeat next time.

    68% picked this

  5. Depletion of the earth’s ozone

    Opposite / Unsupported

    We don't have any reason to think that a change in ozone would affect the troposphere at all. Since ozone warms the stratosphere, if we were to lose ozone then we would lose warmth in the stratosphere, so it would decrease the air temperature in the stratosphere.

    4% picked this

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