USGS Geological Research Activities with U.S. Fish and Wildlife Service

Landscapes

Arctic-Alaska climate monitoring

The USGS plays a critical role in global environmental change research by providing field-based data and information to calibrate and test regional and global ecosystem models. This area of research is a high priority of the U.S. Global Change Research Program and represents an effort to develop research and products that will be useful to the global change research community, and decision making by land and resource managers on the potential impacts of likely future changes of the Earth climate system.

One of the USGS Earth Surface Dynamics Program research efforts is Artic-Alaska climate monitoring, which is being conducted in close collaboration with the USFWS and the. The Global Terrestrial Network-Permafrost (GTN-P) is part of the Global Climate Observing System (GCOS), which was established in 1992 to ensure that the observations and information needed to address worldwide climate related issues are obtained. GCOS is intended to be a long-term operational system capable of providing the comprehensive observations required for monitoring the climate system, for detecting and attributing climate change, for assessing the impacts of climate variability and change, and for supporting research toward improved understanding of the climate system. The GCOS steering committee approved the development of a globally comprehensive permafrost monitoring network (GTN-P) in 1999 to detect temporal changes in the solid earth component of the cryosphere (i.e., permafrost). Changes in permafrost temperature and active layer thickness frequently reflect changes in surface climate over time, and therefore serve as useful indicators of climate change. The GTN-P network is a long-term international effort involving 12 nations and has two primary observational components:

1. active layer (i.e., the surface layer that freezes and thaws annually in cold regions) and
2. thermal state of the underlying permafrost.

Active layer monitoring:

In the U.S., the National Science Foundation and the Department of the Interior (DOI) jointly fund the GTN-P. All 30 of the GTN-P observational sites for active layer monitoring are located in Alaska. DOI currently maintains nine of these active-layer monitoring stations, most of which were installed in 1998. The network provides broad spatial coverage across Arctic Alaska with sites located in the Arctic National Wildlife Refuge (ANWR) and the National Petroleum Reserve Alaska. These fully automated stations continuously monitor:

• Air temperature
• Snow Depth
• Solar radiation
• Shallow permafrost temperature (at several depths)

The DOI stations are co-located with a deep borehole, forming a Permafrost Climate-Detection Observatory. The data from these stations are essential for:

• Detecting contemporary climate changes in the Arctic
• Documenting the sensitivity of permafrost to climate change
• Providing data critical for testing climate models and cryosphere models
• Improving the reliability of impact assessments based on these models

 

Permafrost thermal state

DOI also maintains an array of 21 deep boreholes (>125 m) in the NPRA for monitoring the thermal state of permafrost. Analysis of temperatures from the deep boreholes provided some of the first evidence that the Alaskan Arctic had warmed 2-4 degrees Celsius during the 20th century prior to the mid-1980's (Lachenbruch and Marshall, Science, 1986). DOI's 21 deep boreholes array is the largest array of deep boreholes in the world available for monitoring the thermal state of permafrost. Temperature measurements in this array are important for determining the long-term terrestrial response to climate change in the Arctic.

 

 

 

Lachenbruch, A.H., and Marshall, B.V., 1986, Changing climate: geothermal evidence from permafrost in the Alaskan Arctic: Science, v. 234, no. 4777, p. 689-696.