Glacier Monitoring in Denali National Park and Preserve, Alaska:
Integrating Field Study and Remote Sensing

James Roush and Phil Brease, National Park Service

The objective of glacier research in Denali National Park and Preserve is to develop a regional assessment and long-term monitoring program of glacier mass balance and flow. Glacier monitoring is carried out in Denali to meet the need for interpretation of Park resources, to support Park efforts at long-term ecological monitoring, and to fulfill the international responsibilities of Denali as a Biosphere Reserve. The latter requirement pertains specifically to the need to monitor indicators of global climate change. Glaciers may be among the most sensitive of Park resources to long-term trends in climatic conditions. Monitoring glacier mass balance and the resulting variations in geometry and flow may provide Denali with a measure of climate changes and their magnitude in south-central and interior Alaska. In this way, Denali may provide useful data on climatic trends which will be of interest to the international scientific community, and which will also meet the needs of the National Park Service.

Denali's glacier-monitoring program is currently under development. It is recognized that a major challenge to the goal of glacier assessment and monitoring on a regional (Park-wide) scale is the practical difficulty of glacier field study. In order to address this challenge, a variable scale study design is being implemented which will minimize difficult and costly field work by relying on remote sensing for regional assessments and long-term monitoring. Under this design, only one benchmark glacier is selected for field monitoring in each major climatic region of the Park. These glaciers need to be representative of glaciers in their region, be clearly visible in remotely sensed imagery, and be practical for field study (in terms of size, setting, and accessibility). First, an initial regional inventory of glacier conditions would be made with remote sensing imagery (most likely satellite synthetic aperture radar). The results of that inventory would be used to select suitable index glaciers. Detailed field study of the index glaciers would then be used as ground-truth data for remote sensing studies of glaciers throughout the Park. Finally, the ground-truthed remote sensing imagery would be used for long term monitoring of glaciers on a Park-wide scale.

If successful, Denali's glacier-monitoring efforts will not only support NPS managers and interpreters, but will also provide valuable information for the scientific community at large on the effects of global climate change in Alaska. The results of our research will be shared with those outside the NPS by publication in professional journals and by archiving in the appropriate locations. [an error occurred while processing this directive]