Why is global change research important?

 There is an increased concern today that the earth may not be able to continue to support human needs at the current rate at which we are using the world's resources.  Although humans have been on earth for a relatively short period of time, we have caused much environmental change.  Greenhouse gases like CO₂ (gases that have the ability to absorb heat) and pollutants have caused significant changes in the land surface which have potential effects on global climate, weather, and air quality.  They have also caused disturbances in the earth's ozone layer and many plant and animal species. 

Carbon dioxide is the main greenhouse gas that has been increasing in the atmosphere due to human activity. Since the beginning of the industrial age in the 1880's, CO₂ has risen by almost 25%.  Two of the elements that make up the carbon dioxide cycle are sources and sinks. Two of the sources that have contributed to the rise in CO₂ are deforestation (cutting down of trees) mainly in rainforest areas and burning of fossil fuels (oil, gas, and coal).  A sink is when something absorbs and stores CO₂.  Plants, ocean, and atmospheric absorption of CO₂ are examples of these sinks.

The SDSU Global Change Research Group is conducting research to understand the responses of plants and ecosystems to elevated CO₂ in order to aid the understanding of potential changes, so that leaders can make informed decisions about how to improve the health of the world's plants, animals, and people.

Teacher Research

We (Miss Vevoda and Mrs. Fox) worked with Ms. Kimberly Davis to collect data for the CO₂ research being conducted by SDSU Global Change Research Group during our stay in Barrow, Alaska from March 15 to March 19, 2004.  The equipment we used and the research we conducted is described below.

Measuring CO₂ and Water Vapor

Posted on the tower is, among other instruments, a LI-7500 CO₂/H₂O Analyzer. Mounted to the side of the tower is a control box that has the analyzer electronics inside of it.  It is connected to a sensor head that sits at the top of the tower. The control box is weather proof!  Infrared light passes through the sensor head of the LI-7500 measuring the densities of carbon dioxide and water vapor in the air.   The difference in absorption of the infrared radiation between the beginning of the infrared light path (the bottom of the sensor head) and the end of the path (the top of the sensor head) after it has passed through the outside air gives us the densities of CO₂ and H₂O.  (Click the image to the right for a better look!)

Our job was to take this equipment off the tower and bring it back to the lab so we could calibrate (adjust) it. This was not as easy as it sounds! It was very windy and cold outside, and we were bundled up with our parkas, bunny boots and gloves, which made it difficult to unscrew things and handle wrenches. Once we finished the calibration, we took it back to the tower and remounted it. 

Snow Depth

Barrow's arctic climate is characterized by low temperature, low precipitation and high winds. The average precipitation in Barrow is about 5 inches/year, including snowfall of approximately 20 inches. All About Snow http://nsidc.org/snow/ contains information on snow science, weather, and blizzards. Snowcystals.com http://www.its.caltech.edu/~atomic/snowcrystals/ has a wealth of information including a primer about what snow crystals are, how they form, and why they grow into such diverse shapes.  

We took a series of four measurements at each tower in the directions of north, south, east and west using the tower as the central location. Each line of measurements is called a transect. Each transect consisted of ten measurements that we took every ten meters. We used a steel rod that has centimeter marks carved on the side. We poked the rod into the snow until it reached the frozen ground (permafrost) and then measured the depth of the snow.

LI-7500 CO₂/H₂O Analyzer