Homework Assignment: Keeling Data Set Modern Atmospheric CO2 

Homework Assignment: Keeling Data Set

Modern Atmospheric CO2 

Monthly atmospheric CO2 data an atmospheric monitoring stations, including the Mauna Loa Observatory, Hawaii.

You will need access to excel to complete this exercise. If you don’t have it, you can download office for free here as a CSUEB student: https://www.csueastbay.edu/news/2015/06/06102015.html

You should make a word document with your answers then copy and paste your answers into the submission lin.. Unless otherwise stated, all questions are worth 1 point each.

I. Introduction

The measurements of atmospheric carbon dioxide (CO2) concentrations at the Mauna Loa Observatory are derived from the Scripps Institution of Oceanography's continuous monitoring program. This record constitutes the longest continuous record of atmospheric CO2 concentrations available in the world. Monthly averages* of CO2 in water-vapor-free air are given from March 1958 through present, except for a few interruptions.

A. Atmospheric CO2 Data

Open the Scripps data file that I have attached here.  Open it in excel.  Familiarize yourself with the location of the station where the data was collected by checking out the related web site: https://scrippsco2.ucsd.edu/data/atmospheric_co2/primary_mlo_co2_record.html Note that there is one parameter, CO2, measured monthly. This website does not work well with SAFARI. 

Task 1: Using the web page, scroll down to the Figure of monthly average CO2. Let’s examine this data set.  Answer these questions about the data. I know these are simple questions, but the trends have significance.

1: What units are CO2 measured in?

2: What are the maximum and minimum recorded CO2 for the timeframe 1958 – 2020?

3: Are the values increasing or decreasing with time?

4: is the data smooth or ragged as it increases or decreases?

 

5: Do the data have a pattern, other than just continually going up?

Task 2: 

6: What does the word “oscillation” mean?

7: What does it mean when we say this graph has regular, short term oscillations?

Explore what is the cause of the short-period oscillation of CO2?

(multiple parts to this question):

To explore the answer to the above question, you are to create a chart using the data in the excel file showing ONLY the last 4 years of the CO2 records SPECIFICALLY (Sept. 2016-Sept. 2020). Recall that this is an "xy scatter plot" and NOT a "line plot" when using Excel's chart function.  

The x-axis should be date and the y-axis concentration of CO2.  Note that the months are listed in the documents as numbers 1= January, 2= February, etc, AND is translated into a decimal of each year 2000.041 = Jan 2000, etc. Please use the “plotting in excel” document to help you, and start early so you can ask the professor for help if needed.

This chart should show an xy scatterplot of Date and CO2.

8: Upload your chart of the last four years of data to the homework

(Sept. 2016-Sept. 2020) (3 point)

 

9: How long is each oscillation? (from minimum to minimum or maximum to maximim, you can stretch out the graph to help you see this)

10: What month(s) do CO2 maxima occur?

11: What month(s) do CO2 minima occur?

 

Think about seasonality and how it relates to CO2 uptake through photosynthesis and ocean absorption. When plants are active and have adequate water, they take CO2 out of the atmosphere. View this animation (https://earthobservatory.nasa.gov/global-maps/MOD17A2_M_PSN)  showing monthly variations in net primary productivity and read the explanation.

12: What is Net Primary Productivity (NPP)?

13: What are the units of NPP?

14: What does NPP have to do with Carbon uptake from the atmosphere?

15: What does a negative number mean?

16: What color is the negative number? 

17: After viewing this video and reading the explanation, which month(s) do you think have the GREATEST NPP (Positive CO2 uptake into vegetation)?

18: After viewing this video and reading the explanation, which month(s) do you think have the LOWEST NPP?

Now go back and look again at the graph you made of the last three years of the Mauna Loa CO2 data and compare to the NPP trends with seasons you just looked at.

19: Why might these oscillations occur when they do?

 

20: Is Mauna Loa at high latitudes or low latitudes on the planet? Latitude refers to its North/South position on Earth.

 

21: If you looked at similar data in the high latitudes of Africa (i.e., at the tip), what months would you find the highest NPP? (use the NASA link for this)

 

22: In Southern Africa, what months do you think would have the highest atmospheric CO2 during any single year?

23: In Canada, what months would you find the highest NPP? (use the NASA link for this)

24: In Canada, what months do you think would have the highest atmospheric CO2 during any single year?

25: Explain why and how Canada and Southern Africa differ in this.

26: Given these places are in different hemispheres, which do you think has a stronger effect on land plant-derived NPP? Hint: look at the relative land mass of the Northern and Southern hemispheres.

 

Task 3: Long-term change in CO2 concentrations measured at Mauna Loa.

27: Create an xy graph of the entire time series (March 1958-Sept. 2020). Then add a trendline for the entire time series and upload it to the homework. (3 pts)

28: Using the entire data set calculate how much CO2 has increased per year for the time period 1958-2020. (Hint to get the yearly change divide the total change by the # of years you are interested in.) This assumes that the rate of increase has been constant since 1958.  The next few questions will test that assumption. 

29:  Now, do the same calculations for the time period 1958-1979, then 1980-2000, 2001-2020, then finally for the time period 2010-2020.

30: How has the rate of increase changed? Meaning, is there evidence that the rate is actually systematically increasing or decreasing over the years?

31: If you wanted to predict the CO2 levels in the atmosphere 30 years in the future, which calculation would you use? 1958-2020, 1958-1979, 1980-2000, 2001-2020, or 2010-2020?

32: Explain your answer to Question 31.  (2 pts)

33: Now that you have the tools, calculate what you predict CO2 levels would be in 2070. (2 pts)