Part 1: Overview of the Carbon Cycle

The carbon cycle is a complex system with interactions between the different components of the Earth System. In this homework, you will learn how carbon is moved between the different reservoirs naturally, and how human activities are changing the cycle.

Volcanic eruptions (0.6 GT/year)

Dissolution of atmospheric carbon in surface ocean (90 GT/year

Photosynthesis on land (110 GT/year)

Release of carbon from surface ocean to atmosphere (90 GT/year)

Leaf fall to soil (60 GT/year)

Uptake of carbon from surface ocean by ocean life (10 GT/year)

Respiration from life on land (i.e., plants, 50 GT/year)

Downwelling (mixing) from surface to deep ocean (96.2 GT/year)

Respiration from soil (59.4 GT/year)

Upwelling (mixing) from deep ocean to surface ocean (105.6 GT/year)

Runoff of soil to surface ocean (0.6 GT/year)

Dead ocean life sinking to deep ocean (10 GT/year)

Deposition of sediment from deep ocean to rock (0.6 GT/year)

1.The diagram above shows the reservoirs of the carbon cycle with the mass of carbon in Gigatons. Using PowerPoint or the “Draw” feature in Microsoft Word, draw labelled arrows between the relevant reservoirs to represent the sinks and sources listed in the table above. Save your PowerPoint slide as an image (watch the tutorial video if you need help) and insert the image in the space below.  (13 points)

2. 

[Insert your completed carbon cycle diagram here. ]

3.Ignoring the solid Earth, which of the reservoirs has the longest residence time and which has the shortest residence time? What are the residence times of carbon in each of these? (4 pts)

Longest

Reservoir:

Residence time:

Shortest

Reservoir:

Residence time:

4.Your diagram currently represents how the carbon cycle operated before humans started affecting the atmosphere. Is the carbon cycle at a steady state today (as in the year 2024)? How do you know? (2 pts)

5.What extra arrows would you need to draw on the diagram to represent human activities that affect the carbon cycle? Where would they flow from and to? Describe at least two. (2 pts)

6.What effect do you think these additional fluxes will have on the size of the different carbon reservoirs? (2 pts)

Part 2. Interactive Carbon Cycle Simulation for “Business as Usual”

In this step, you will use an online carbon cycle simulation to observe how human activities are impacting the flux of carbon through the Earth System.  You will need to “ESS15_W24_HW5_CarbonCycle.xlsx” file and this link for the website.

1.For the first simulation, you will use the lesson Carbon Cycle and keep the parameters of fossil fuel use and net deforestation at their pre-set values of 2%/yr and 1 GT/yr, respectively.

This simulation will show you what the future carbon cycle will look like if we continue the “business as usual” pathway of using fossil fuels and deforestation at our current global rates.

Familiarize yourself with the carbon system diagram on the right. The main reservoirs of carbon are labeled, and their initial sizes are shown. For example, in year 2010, the size of the terrestrial plants carbon reservoir is 700 GT and the size of the atmosphere is 720 GT. As you progress through each decade of the simulation, these values will change, and we will keep track of this information in our spreadsheet.

Begin the simulation by clicking the green “run decade” button.

At each decade interval, fill in the corresponding data table in the Excel spreadsheet. Complete the simulation through the year 2120. (5 pts)

*Hint: the sizes of the soil, ocean surface, and deep ocean reservoirs do not change, but rather show the +XX GT change. In your table, start with their initial values for 2010, and then add formulas for the following decades. For example, with the surface ocean you can do: = 1000+XX, or deep ocean: =38000 + YY where XX and YY are the respective increases in those reservoirs per decade of the simulation. This way the math is done for you automatically on your Excel table.

2.Using the collected data, make a plot of the different reservoir sizes in GT (atmosphere, surface ocean, deep ocean, soil, and plants) from 2010 to 2120. Put the deep ocean on a secondary y-axis (watch this video for help). Insert your figure below. Be sure to include appropriate axes labels and units, a legend, and a title. (5 pts)

3.Calculate the rate of change in the size of each of the reservoirs from 2010 to 2120.

where t is the current time step (ex: year 2030) and t-1 is the previous time step (ex: year 2020). The atmosphere’s rate of change is started for you.

Make a figure for the rate of change for each reservoir and insert your figure below. Be sure to include appropriate axes labels and units, a legend, and a title. (15 pts)

4.What do you observe in the rate of changes in the different carbon reservoirs over time? Are they all the same? Or do some change more/less than others? In at least one paragraph, discuss your observations. (5 pts)

5.Calculate the amount the carbon emissions (in percent) that end up in each reservoir for each decade. This can be done by first determining the change in the reservoir’s sizes after each decade. Then divide these values by the total emissions of carbon at the time step (column G, “Smokestack”). For example, if the atmosphere changed by 10 GT and the total emissions were 100 GT, the percent of the total emissions that ended up in the atmosphere at that time step would be 10%. Remember that Excel acts as a calculator, so you can type formulas in a cell and drag!

Make a graph of the results and insert your figure here. Be sure to include the appropriate axes labels and units, a legend, and a title. (15 pts)

6.What do you observe about where carbon ends up in the Earth System through time in this scenario? Do all the reservoirs “accept” the same amount of carbon or are some different? Is the amount of carbon ending up in each reservoir the same at every time step or does it change? In at least one paragraph, discuss your results. (5 pts)

Part 3. Interactive Carbon Cycle Simulation for a “Drawdown” Scenario

1.For the second simulation, you will change the lesson to “Curb Emissions” and reduce the parameters of fossil fuel use and net deforestation at to -4%/yr and -4 GT/yr, respectively.

Press “RESET” to set these parameters. This simulation will show you what the future carbon cycle will look like if make drastic cuts to our carbon emissions by stopping fossil fuel use and deforestation. 

      Begin the simulation by clicking “run decade”. At each decade interval, fill in the corresponding data table in the       Excel spreadsheet. Complete the simulation through year 2100.

      Using the collected data, make a plot of the different reservoir sizes from 2010 to 2100. Insert your figure below.      Be sure to include appropriate axes labels and units, a legend, and a title. Put the deep ocean on the secondary      y-axis (10 pts)

2.Compare and contrast the differences in the carbon reservoirs with this curb emissions scenario and the “business-as-usual” scenario. (5 pts)

3.Continue running the curb emission scenario out into the far future (2500). You do not need to record the data. While you do this, pay attention to the different reservoir sizes and to the atmospheric CO2 concentration. Describe what happens to carbon in the Earth System in the future. Where does the carbon that had been emitted to the atmosphere prior to 2010 end up? Is this a slow or fast process? (5 pts)

4.From what you have witnessed in this “curb emissions” scenario, explain the concept of “climate inertia”. Use the internet if you need to and cite your sources (links are acceptable). (5 pts)

5.With the concept of “climate inertia” in mind, why is it important that we begin curbing carbon emissions as soon as possible? (2 pts)

6.In one paragraph, summarize what you learned from this homework activity. (2 pts)

                                                 Evolution: Founding Theories and Principles Lab Reporting Worksheet

In science, reporting what has been done in a laboratory setting is incredibly important for communicating, replicating, and validating findings. However, writing scientific reports can be a little overwhelming. There is a set of agreed-upon components that the scientific community requires when reporting scientific research. Answer the following questions to describe what occurred during the lab you conducted in Labster. Be sure to use complete sentences and QUESTIONs that fully represent what you experienced. Writing a lab report is less about being correct or incorrect than it is accurately reporting what happened and why. So, do not worry about reporting data that might seem counterintuitive or unexpected. Focus on clearly communicating what you did and what you observed.

Write your answers on a new line.

Title

What was the title of the lab you completed?

What was the subject you were trying to understand better in the lab?

What information from the textbook and classroom is relevant for the subject you were trying to gain a better understand of in the lab? Identify the concepts and explain how they are related to the lab topic.

• During the lab, what information from the theory section provided additional background information about the subject? (To review the theory section, launch the lab and click the Theory tab on the top of the data pad). Identify the concepts and explain how they are related to the lab topic.
• Most scientific observation involves examining phenomena or processes. What phenomenon or process were you observing in the lab? What were you able to change and explore? What did the simulation not allow to change?
• You have already described the phenomenon or process you studied in the lab in the previous section. Now, take some time to fully describe the steps you took during the lab. Do not include the process of you logging into the lab in your QUESTION. For this virtual lab, a short, high-level summary will suffice. 
• Describe some of the observations you made. What did you write down or keep track of? What did each of your senses observe during the lab process? What did you see (e.g., changes in colors, movement, shapes, sizes, patterns)? What, if anything, did you measure? What did you hear (e.g., sounds from reactions, collisions, error messages)? What did your lab character touch? Did you notice anything that seemed unexpected? Did you notice anything that you did not expect to observe?
• Which parts of the lab required you to think more than others and required more time? Which parts were simple and completed easily?
• What did you notice about the phenomenon or process you explored? 
• Describe any information about the phenomenon or process that you learned.
• During your lab, what happened that might have had an impact on the accuracy of your observations? Did the simulation alert you that an error was occurring? If so, how did you resolve it?
• The discussion section also is used to summarize big ideas from the lab. What were the important learnings about the phenomenon or process from the lab?
• After scientists have identified how the new knowledge fits into the old knowledge, they discuss the implications of the new information for moving forward. In this class, the purpose of study is to learn some foundational science ideas represented by the course learning outcomes. Review the course learning outcome aligned to this lab in the assignment directions in Blackboard. How is the information from this lab related to the course learning outcome? What knowledge has the lab supported you with learning that is related to this course learning outcome?
• Following scientific research, scientists usually come up with new questions that result from what they learned. These new questions often end up leading to new research in the future. What additional scientific things do you wonder about after completing and writing about your lab experience? 
• Topic
• Background Information
• Method

Describing what you did during a lab supports other scientists in replicating your work. It is through this consistent replication that scientists are able to see repeating patterns and develop ideas that help move science forward. When you discuss your observations, in a later section, you will have to describe, in detail, what you did. You may also have to describe what choices you made, why you made them, and any concerns about things that occurred that were unexpected. To have enough information to do this, you need to keep very detailed notes. What doesn’t seem important in the moment may end up being something that explains your findings later. A benefit of conducting virtual labs when learning science, is that many potential errors are controlled for you. The virtual lab environment often will alert you if something is not going the way it should. This does not occur in non-virtual settings. The virtual lab setting can be very helpful to learners for this reason. However, we still need to practice documenting so those skills are practiced for the lab experiences when technology will not be there as a coach.

Observations

Many lessons learned from scientific research come from the reporting and analysis of data and observations. This part of scientific reporting requires detailed QUESTIONs of technical information and observations, as well as high-level synthesis of information. High-level synthesis requires a mastery of foundational content in the related scientific field and a complementary mastery in some field of quantitative and/or qualitative analysis. For this report, let’s focus on big picture patterns. 

Discussion

The discussion section is used to explain why things might have happened the way that they did in your research. Here, scientists describe any potential anomalies or mistakes and why they think they may have occurred. 

Conclusion

The conclusion section of a lab report describes how the learnings from the lab research fit in to prior scientific knowledge. This is done by comparing new information to previously known information that was identified in the section of your report that discusses background information.

Acceleration project

Purpose

Students will explore acceleration.

Theory

Acceleration happens any time the speed changes. This is its definition—a

time-change in speed: a = dv/dt. Zero

acceleration means the velocity is not changing. Thus it is possible for speed to be zero when acceleration is not (as when a rocket first starts its engines) and for acceleration to be zero when speed is not (as when an elevator is in steady motion).

An accelerometer is a device that detects acceleration. Modern versions use semiconductors in which electrical transmission depends on the internal stresses. Earlier varieties used simple springs, but there is a far easier way.

Procedure

1. Procure a water bottle and a piece of cord or string. Dental floss can be used, as can a thread pulled from aging cloth. It needs to be four inches or so.
2. Attach a small weight to the end of the string. It can be a bit of twig or a ball of aluminum foil, but it must float in water when the time comes for that.
3. The label needs to be peeled off the bottle because the weight will hang in it and needs to be visible. The easiest way to hang the weight in the bottle is simply to screw the cap on, trapping the thread against the rim.
4. Set the bottle upright on a tabletop or a smooth floor and give it a minute for the hanging weight to stop moving.

Now push the bottle suddenly to away and observe the weight. It responds to the acceleration-in fact its horizontal displacement is pretty much linearly proportional to the acceleration, but note the direction.

5. It should be possible to move the bottle forward at a steady speed along the floor or table (or just carry it) so the weight doesn’t move appreciably.

Quickly stop it and observe the motion of the weight. This event is a negative acceleration—a deceleration.

6. Fill the bottle with water with the weight still in there. Screw the cap on to trap the string again. Turn the bottle upside-down do the weight floats in the middle. Repeat steps 4 and 5.

Analysis

From the outside perspective, the weight swings backward if the bottle accelerates forward because the bottle is trying to leave the weight behind.

From the viewpoint of the bottle, there is an “acceleration force” like the one seeming to push people back in their seats when a car accelerates.

Please answer each of the following in Canvas using complete sentences:

1. When the bottle moved at a steady speed, what was its acceleration?
2. If the bottle is left to sit, the weight grows still, but the surface of the earth is going east at 1000 MPH. Why doesn’t the accelerometer respond to this?
3. Suppose the bottle were hung from the ceiling in a car and the car sped up.

The bottle would swing back in the car.

What would the weight do within the bottle (no water, just air)? Why?

4. Did the weight do something weird when the bottle was accelerated while full of water? What did it do? Why?

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PROBLEM SET 3: Kinematics

1. A movie stuntwoman drops from a helicopter that is 30.0 m above the ground and moving with a constant velocity whose components are 10.0 m/s upward and 15.0 m/s horizontal and toward the south. You can ignore air resistance.

1. Where on the ground (relative to the position of the helicopter when she drops) should the stuntwoman have placed the foam mats that break her fall?
2. Draw x-t, y-t, Vx-t, and vy-t graphs of her motion.

2. A water hose is used to fill a large cylindrical storage tank of diameter D and height 2D.

The hose shoots the water at 45° above the horizontal from the same level as the base of the tank and is a distance 6D away (see figure). For what range of launch speeds (vo) will the water enter the tank? Ignore air resistance, and express your answer in terms of D and g.

3. If7 = bt? + ct3j, where b and c are positive constants, when does the velocity vector

make an angle of 45.0° with the x- and y-axes?

4. The earth has a radius of 6380 km and turns around once on its axis in 24 h.

1. What is the radial acceleration of an object at the earth’s equator? Give your answer in m/s and as a fraction of g.
2. If arad at the equator is greater than g, objects will fly off the earth’s surface and into space. (We will see the reason for this in Chapter 5.) What would the period of the earth’s rotation have to be for this to occur?

5. According to the Guinness Book of World Records, the longest home run ever measured was hit by Roy “Dizzy” Carlyle in a minor league game. The ball traveled 188 m (618 ft) before landing on the ground outside the ballpark.

1. Assuming the ball’s initial velocity was in a direction 45° above the horizontal and ignoring air resistance, what did the initial speed of the ball need to be to produce such a home run if the ball was hit at a point 0.9 m (3.0 ft) above ground level? Assume that the ground was perfectly flat.
2. How far would the ball be above a fence 3.0 m (10 ft) high if the fence was 116 m (380 ft) from home plate?