Sampling the Waters: Carbon Cycle Research in Remote Arctic River Basins

September 15, 2004

Arctic terrain has historically been a sink, or collector, of carbon from the atmosphere. Soils in the Arctic accumulate up to one-third of the entire earth’s organic carbon. When the climate warms, carbon that had been locked in frozen peat and other permafrost zones is released through melting. Released carbon then enters rivers and streams and flows into the ocean, in addition to entering the atmosphere in gas form. River basins are therefore very important sites for studying carbon cycles and the consequences of climate and environmental change.

Figure 1. Map showing Arctic river basins

Location of Pilot Station, AK, one of the water sampling sites

IARC researcher Dr. Laodong Guo and a research team, funded by IARC/NSF, are doing water sampling in the Mackenzie, Yukon, and Sagavanirktok/Colville River Basins (Fig. 1). These rivers flow into the Arctic Ocean, and the Bering and Beaufort Seas, respectively. The sites were chosen because they are representative of arctic rivers in North America. The biological and chemical composition of these waters can give scientists a lot of information about each area’s reaction to climate change. Remote Arctic river systems usually experience very little anthropogenic, or human, impact on their ecosystems. Because of their isolation, they make ideal “field laboratories” for carbon cycle and climate change research. The cycle of carbon through soil, water, ice, and atmosphere is an important concern, since released carbon may enter the atmosphere in the form of carbon dioxide and create a positive feedback loop to global warming. The researchers will do radiocarbon dating and water chemistry testing to determine the type and quantity of organic carbon carried by rivers into the ocean and to understand the relationship between the carbon cycle and climate change.

This project is one of the first to combine field observations and controlled laboratory experiments on a molecular level in large, remote arctic river basins. The study will help to identify the effects of changing climate conditions within a community and on the overall ecosystem in the short and long-term future. Data from this research can be used for both arctic and global models on carbon cycling and natural and human impacts.

This research project supports the primary goal of IARC, which is reducing uncertainty in climate change prediction, and creating effective climate models. It integrates several important research areas: hydrology, soil/permafrost dynamics, biogeochemistry, land/ocean interactions, and carbon cycles. The project is an exciting combination of small-scale molecular-level testing and large-scale processes.

Dr. Guo has been traveling to Pilot Station, Alaska to do sampling in the Yukon River delta (see map). This remote village of approximately 600 residents is located on the northwest bank of the Yukon River and has no external road system. The main forms of transportation are by small aircraft, boat, and snow machine. Pilot Station is a good area for their research because the downstream waters are characteristic of the entire river basin. In addition, other major Yukon River tributaries, such as the Tanana and Porcupine Rivers, will also be sampled.

Education Outreach is another important component of the project. Local school teachers and other members of the community are very interested in research that is taking place right in their backyard. On a future sampling trip, Dr. Guo and Research Assistant Tohru Saito will give presentations to students and residents at the Pilot Station School describing sampling techniques and what they hope to learn about this area of the Yukon River delta. Dr. Guo notes that “this interdisciplinary research will be a productive linkage between discovery and education/outreach to the society. Under the leadership of IARC Director, Dr. Syun-Ichi Akasofu, this project will greatly promote public outreach in global and arctic climate change through collaboration with local agencies and involvement of local communities and K-12 students.”

The village of Pilot Station, AK, located on the NW bank of the Yukon River

Traveling to water sampling sites on the Yukon River

Smoke from the 2004 wildfires is visible in these photos.

IARC researchers Dr. Laodong Guo and Claude Belzile collect water samples and log data.

Water filtration equipment set up on site (left), preparing samples for later testing (right).

Photos are courtesy of L. Guo