Essay #1: Temperature Trends in Your Hometown
1. Use online resources to access temperature data in any town you choose
2. Use Excel to create graphs
3. Analyze temperature graphs to look for climate trends
4. Compare temperature data from satellite and ground station sources
5. Discuss the usefulness of running averages
6. Compare the temperature data from your town with that of another student
7. Discuss how this assignment applies to how you will critique temperature trend information in the future
In this essay assignment, you will download temperature data from any town you would like to know more about. This could be a town you or a family member have lived in, a place you have visited, or a town you would like to live in. The temperature data you download will be from satellite and ground station sources. You will graph that data as well as running averages of that data.
Once you have graphical representations of the temperature data from your town, write an essay that answers the following prompts:
1. Briefly describe your town. This should include the name of the town, the latitude and longitude of the town, some historical background, why you chose it, and any other relevant or interesting information about the town.
2. Compare the graphs of satellite and ground station temperature data. This should include a short explanation of how each of these sources gathers information, a comparison of time periods the two sources cover, and an analysis of the graphs specifically addressing whether there is a climate change trend. Include the average winter and summer temperatures, and a discussion of how much year-to-year variation in temperature there is.
3. Compare the 5 year running averages of temperature to the average temperature graphs. Include a discussion of why a running average is useful, and what kind of trends you can see in the data when you use a 5 year running average.
4. Discuss the difference between the different sized running averages (5 year, 11 year, and 21 year). What are the advantages and disadvantages of using these different sizes?
5. Compare your findings about the temperature record in your town with another student from a different geographical area. You can use the Piazza forum tool on the class website to contact another student. Discuss the similarities and/or differences in the temperature trends between these two locations. Can you think of an explanation for those similarities and/or differences?
6. Conclude with a discussion of whether what you learned in this assignment will influence how you look at reports of climate change and why/how.
7. Please include your graphs as an appendix (not in the main body of the essay; copy and paste the graphs on the last page(s) of the essay).
Bloom, Arnold J (2010) Global Climate Change, Convergence of Disciplines, Sinauer Associates, Inc, Sunderland, Massachusetts.
Goddard Institute for Space Studies (2009) Global Temperature Trends: 2008 Annual Summation. http://data.giss.nasa.gov/gistemp/2008/ accessed September 22, 2012.
National Research Council (2006) Surface Temperature Reconstructions for the Last 2,000 Years , The National Academies Press, Washington, D.C., http://www.nap.edu/catalog.php?record_id=11676 accessed September 22, 2012.
NASA’s Surface meteorology and Solar Energy data http://eosweb.larc.nasa.gov/sse/ accessed September 22, 2012.
NASA’s Ground station temperature data http://data.giss.nasa.gov/gistemp/station_data/ accessed September 22, 2012.
NOAA’s Ground station data http://www.ncdc.noaa.gov/cdo-web/#t=secondTabLink accessed January 12, 2013.
Weather measurements are made at observing stations or by weather satellites.
Obtaining the Data
Visit the website for NASA’s Surface meteorology and Solar Energy data (select link above or paste this URL into your browser: http://eosweb.larc.nasa.gov/sse/).
1. Click on “Meteorology and Solar Energy”
2. Click on “Interannual Variability”
You will be asked to enter an e-mail and password, and then some additional information. This information is used by NASA so they can track how many people are using their data. You can choose to not be contacted about using their data.
3. Enter the longitude and latitude of your chosen location, which you can find at http://www.latlong.net/.
4. The start year should be 1983 and the end year should be 2005.
5. For “select one parameter,” select “minimum air temperature at 10 m.”
6. Hit “submit.”
You will get a chart with the year, the monthly average minimum temperature, and the annual minimum temperature.
7. Select the data in the chart, copy it, and paste it into the Excel spreadsheet on the tab labeled Your town min temp, in cell A1 .
8. Hit the “back arrow” on your web browser to get back to the page where you were asked to enter the longitude and latitude of your town (these should still appear on this page).
9. Change the “select one parameter” to “maximum air temperature at 10m.”
You will get a chart with the year, the monthly average minimum temperature, and the annual maximum temperature.
10. Select the data in the chart, copy it, and paste it into the Excel spreadsheet on the tab labeled Your town max temp, in cell A1.
Ground Station Data (NASA)
Click on the following link: Ground station temperature data (or paste this url into your browser: http://data.giss.nasa.gov/gistemp/station_data/). If this website is not functioning, please follow the directions for Ground Station Data (NOAA) found below.
1. From this site you can find data from the weather station closest to the town you’ve chosen to look at.
2. In the Download Station Data box, enter a station name to search for and hit search.
For example, if one grew up in Sunnyvale CA and types in Sunnyvale, one will not get any weather stations. But if one searchs for the closest large city, San Jose, one will get 5 weather stations to choose from. You will need to verify that the longitude and latitude of the weather station you choose is close to that of your town. For example, one will want to be sure one selects San Jose, California (37.4°N, 121.9°W), not San Jose, Costa Rica (10.0°N, 84.1°W). You can find the longitude and latitude of your town at http://www.latlong.net/.
3. Select “download monthly data as text.”
4. Now getting the data into your spreadsheet will take a couple of steps:
a. Select all the data and copy (both commands are under the Edit menu).
You will need to eliminate any erroneous data. This appears as the number 999.9 in the spreadsheet. Under the “Home” tab, click on the binoculars (find & select) button and select “Replace” (or type Ctrl and “F”: hold control while you hit “F”). Hit the “Replace” tab. For Find, enter 999.9 and for Replace, keep it blank. Hit “Replace All” (this command should replace all of your 999.9 entries with blanks).
b. Open a blank Excel worksheet and paste the data into it. Save this file as a .csv file(select “Save As” and change the file type to .csv).
c. Go back to the Excel file entitled ESSAY 1 and go to the tab titled “your town ground.”
d. Select cell A1 and under the DATA tab/menu, select “get external data, from text” (or “get external data”, then select “import text file”).
e. Select the .cvs file you saved and hit “import.”
f. In the text import wizard, select “delimited” (instead of “fixed width”).
g. In the next window, select Tab and Space and hit “next.” For all other prompts, keep the default settings and hit “Finish.” Your data should now appear with each data point in its own data cell.
Ground Station Data (NOAA)
1. If the NASA website is not working, go to the NOAA National Climatic Data Center (Climate Data Online: Text & Map Search) Website at http://www.ncdc.noaa.gov/cdo-web/#t=secondTabLink.
2. Enter the zip code or the name of your hometown in the (1) box that says "Enter search term(s) for station name, location name, ZIP code, etc."
3. Select from the drop down list (2) for "Select a data set or product to search" the product "Monthly Summaries GHCND".
4. Click the (3) SEARCH button.
5. If several weather stations are listed on the next webpage that appears, choose the one that is most appropriate: the one that is closest to the location you want and has the longest period of record (at least several decades). You can details from clicking "Full Details" or "Quick Details".
6. Once you have decided on a weather station, click on "Add to cart" button. (Do not worry; despite the name, you are not purchasing anything.)
7. Then click on the “Cart (Free Data) 1 item” button toward the upper right of the webpage.
8. On the "View/Edit Your Chart" page that opens go to the column on the right side that say "Additional options".
9. In the left box under the Label "Output date range" click the calendar icon on the right side of the box (a red grid with a green pin) and choose the earliest date. You will have to scroll up the drop down list for year to pick the earliest year. Click on the day of the month. Alternatively you can type in the date in the format yyyy-mm-dd (y=year, m=month, and d=day).
10. In the right box under the Label "Output date range" click the calendar icon on the right side of the box (a red grid with a green pin) and choose the most recent date. The default selection is probably fine. Click on the day of the month. Alternatively you can type in the date in the format yyyy-mm-dd (y=year, m=month, and d=day).
11. In the boxes under the Label "Select the output format", pick the second one "Custom Monthly Summaries of GHCN-Daily CSV" and click the small round button. It should now have a black dot in it.
12. Click the orange "Continue" button at the bottom of this Additional options box.
13. On the next page "Custom Output - Monthly Summaries GHCND" in the box on the left "Select data types for custom output" click the box beside "Air Temperature". It should contain a green check. Click the orange box "Continue to Review" on the bottom of the page.
14. On the next page "Review Order" in the right column box under "Enter email address", enter your email address and verify it. Click on the orange "Submit Order" box below.
15. You will almost immediately receive a notification of the order in an email from NCDC CDO email@example.com and then several minutes later receive a hyperlink with the source of the data in another email from the same source.
16. Click on the hyperlink, and you should be given the option of opening the file with your spreadsheet or saving it as a file on your computer. It is probably easier to just open it with your spreadsheet. The file will have in the first column the station number, the second column the date in the format yyyy-mm-dd (y=year, m=month, and d=day). The next five columns EMNT - EMXT - MMNT - MMXT – MNTM stand for, respectively, Extreme Minimum Temperature for the Month, Extreme maximum temperature for the month, Monthly mean minimum temperature, Monthly mean maximum temperature, and Monthly mean temperature.
17. You have to divide the listed numbers by 10 to get the temperatures in degrees Celsius. The spreadsheet can do this for you: in the Cell of the spreadsheet H2, type =c2/10 and enter. This cell should show the Extreme minimum temperature for the month in Celsius. Copy the formula in cell H2 and paste it into cells I2, J2, K2, and L2. Then paste the formula into as many rows as you have monthly data.
18. Copy and paste these data into the appropriate cells of spreadsheet template that we provided. You will probably have to use Paste Special Values. Also using Paste Special Values Transpose will save you time because you can do a whole year (12 months) at once.
Graphing the Data
A. February min average temperature
1. Highlight the year column.
2. Hold down the control (CTRL) button and highlight the February column
3. Click the “Insert” tab and hit the Scatter button, select scatter with straight lines and markers. Copy and paste the graph onto a new sheet
4. Label the Chart (the steps for labeling the chart and axes can vary by computer, please refer to Excel Help if you need directions).
5. Label the Y-axis (temperature in degrees C).
6. Label the X-axis.
7. Adjust the Y-axis so both of the February charts are on the same scale (do this for all pairs of graphs). To do this:
a. Click (or left click) on the Y axis. This should display the display the Chart Tools tabs (Design, Layout, and Format).
b. Click on the Format tab.
c. Under “Vertical” (Value) Axis, hit “Format Selection.”
d. In the Axis Options table, change the Minimum and Maximum from Auto to Fixed and enter the values you want. For example, you will want the February minimum average and February minimum 4 year running average temperature graphs to both be on the same scale (for the Davis temperature graphs this is 0-8 degrees C).
B. February min 5 year running average temperature
C. July max average temperature
D. July max 5 year running average temperature
A. February average temperature
B. February 11 year running average temperature
C. July average temperature
D. July 11 year running average temperature