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Rocky Raccoon: Using Data to explore Carbon in the Rocky Mountains

Access Rocky Raccoon Data.

This page was prepared by Sherri Heck in collaboration with Steve Aulenbach, Michael Burek, and Britt Stephens of the National Center for Atmospheric Research (NCAR) and edited by Aleshia Mueller (SERC).

Author Profile

The Dataset

The Breathing Forest: Exploring the Carbon Cycle and Climate Change in the Classroom using Rocky RACCOON carbon dioxide data.
The Rocky Mountain Regional Atmospheric Continuous CO2 Network (Rocky RACCOON) comprises two to three years of carbon dioxide (CO2) concentration data. The carbon dioxide data are gathered using the Autonomous Inexpensive Robust CO2 Analyzers (AIRCOA) that are positioned on mountain tops in Colorado and Utah (see field site images of Storm Peak Laboratory (SPL), Fraser Experimental Forest (FEF), Niwot Ridge (NWR) and Hidden Peak (HDP)). The data are gathered at various heights approximately every 2.5 minutes. The Rocky RACCOON project was created and is managed by Britt Stephens of the National Center for Atmospheric Research (NCAR).

Use and Relevance

Rocky RACCOON collects information about the amount of carbon dioxide that is in the atmosphere. Carbon dioxide is a major greenhouse gas and is emitted by various human (anthropogenic) and natural sources. For example, land use changes (biomass burning), traditional transportation (i.e. automobiles, airplanes, etc.), coal-fired power plants, volcanoes, and decaying plants all emit carbon dioxide. By acting as a greenhouse gas, carbon dioxide absorbs the outgoing infrared radiation from the earth, therefore trapping some of the heat that would otherwise be emitted out to space and increasing the atmospheric temperature. The amount of carbon dioxide in the atmosphere has been increasing at a rate of approximately 1.5ppm/year. However, this value is still increasing. The carbon cycle is the movement of carbon through the atmosphere, terrestrial biosphere, geosphere and oceans. Forest ecosystems, as apart of the terrestrial biosphere, such as the ones in Rocky RACCOON take up (photosynthesis) and give off (respiration) carbon dioxide. Scientists use carbon dioxide concentration data generated from the Rocky RACCOON project to better understand how forest ecosystems affect the carbon cycle and therefore the climate.

Use in Teaching

This data provides an opportunity for educators and students to be a part of scientific research involving topics and skills in photosynthesis and respiration in mountain forests and their connection to the carbon cycle and climate change.


  • Plant photosynthesis and respiration
  • The role of forests in the carbon cycle
  • How the carbon cycle changes on daily, seasonal, and yearly timescales
  • Factors that have contributed to an increase in carbon dioxide
  • The effect of synoptic weather patterns on carbon dioxide concentrations


  • Using data to make hypotheses about factors that effect the carbon cycle
  • Using the data to make visualizations of temporal changes of the carbon
  • Interpreting when photosynthesis and respiration is occurring
  • How weather conditions effect the atmospheric carbon dioxide concentrations

Exploring the Data

Data Type and Presentation

Raw hourly carbon dioxide concentration data are processed and represented as space-delimited text files which can easily be downloaded and used in Microsoft Excel. The data are archived for the years 2005 and 2006 to present.

Accessing the Data

Go to the Rocky RACCOON website to access data for each of the four sites. The scroll bar on the left-hand side of the webpage displays the acronyms for the four sites: FEF (Fraser Experimental Forest), NWR (Niwot Ridge), SPL (Storm Peak Laboratory) and HDP (Hidden Peak). Below each of the acronyms are three additional links. For example,

Site Info
Full Record
Latest: 070619

By clicking on the "Full Record" link the user will be directed to a webpage that contains the data file for that location. At the top of this page there is a link to the "Hourly Datafile". This link will bring the user to the complete hourly data record, as described above in the "Data Type and Presentation" section. The "Site Info" link will give the user information on the instrument site location, such as latitude, longitude, and altitude along with several pictures of the site. The "Plots/Diagnostics" link will provide the user with a graph of the full data record and the most recent diurnal data record. Just below the "Diagnostics" graphs is a link to a suite of diagnostic plots that are used to ensure the instrument is working properly.

Manipulating Data and Creating Visualizations

One way to process this data is to create graphs using a spreadsheet application such as Excel. Graphs could be used to visualize the changes of the carbon dioxide concentrations on various time scales.

Once the user reaches the hourly data file it can be saved as a text file by right clicking the mouse and saving it in either Notepad or Wordpad. The user should then open the text file and delete the paragraphs of text which describe the data except for the header just above the data that indicates what each column represents. The data that the user may be interested in is in the column entitled "CO23". This is the carbon dioxide data from the highest inlet height for its respective site. In addition, the "month", "day" and "hour" are also listed. The data are recorded for every hour of the day.

Tools for Data Manipulation

A spreadsheet application such as Excel is the primary data analysis tool.

Download the hourly data, save it, and open it in Excel. Go to the top-left of the toolbar and click on the icon that looks like a slightly opened folder. This will open a small window showing available data files. Navigate to the directory where you saved the data file, click on it, and then click "open". Another small window will open. Be sure the "delimited" option is selected and then click "Next". In the next window, ensure that "Tab" and "Space" are selected and then click "Next". In the next window, be sure that "General" is selected and then click "Finish". This will import the data file into Excel with each variable in its own column. The user may then create various time series plots of carbon dioxide concentrations.

To make a graph of the data, click on the chart icon in the top toolbar (it looks like a colorful histogram). If it is not on the toolbar, then click on "Tools" and select "Chart".

Further instructions on plotting data in Excel may be found at the following websites:
Physics Laboratory, Excel Tutorial 7: Graphing Data and Curve Fitting
Internet for Classrooms (I4C), Using Excel in a classroom: Creating a Chart or Graph
SERC: How to Use Excel

About the Data

Collection Methods

Raw measurements are collected approximately every 2.5 minutes using the Autonomous Inexpensive Robust CO2 Analyzer (AIRCOA). The measurements are then averaged over a period of one hour. The data are transmitted to the Rocky RACCOON website via the internet.

Limitations and Sources of Error

Rocky RACCOON data have been compared with the National Oceanic and Atmospheric Administration (NOAA) carbon dioxide measurements and indicate an intercomparibility of +/- 0.2ppm or better. If and when there are issues with the data indicated by "-999.99", the user may go to the "Notes" link (next to the "Hourly Datafile" link) to see why the data are missing.

References and Resources

Scientific References that Use this Dataset

Stephens, B.B., Watt, A., Maclean, G. (2006), An autonomous inexpensive robust CO2 analyzer (AIRCOA). 13th WMO/IAEA Meeting of Experts on Carbon Dioxide Concentration and Related Tracers Measurement Techniques, J. Miller ed., WMO TD no. 1359, 95-99.

Rocky RACCOON data will soon be included in NOAA's CarbonTracker.

Other Related Scientific References

Bakwin et al., 2004. Regional CO2 Fluxes From Mixing Ratio Data. Tellus, 56B, 301-311.

Helliker et al., 2005. Regional-scale estimates of forest CO2 and isotope flux based on monthly CO2 budgets of the atmospheric boundary layer. The Carbon Balance of Forest Biomes, 77-92.

Law et al., 2002. Using high temporal frequency data for CO2 inversions. GLOBAL BIOGEOCHEMICAL CYCLES, Vol. 16, NO. 4, 1053.

Intergovernmental Panel on Climate Change (IPCC) 2007 WG1 Chapter 7. Coupling Between Changes in the Climate System and Biogeochemistry. WG1, Chapter 7, 499-588. Download PDF.

North American Carbon Program (NACP):
http://www.carboncyclescience.gov/documents#nacp 'Guiding documents and other materials'
State of the Carbon Cycle Report PDF

Other related Education Resources

Related Links

Schematic of the AIRCOA instrument