Gates Glacier climate station, Wrangell-St. Elias

Climate Monitoring Status and Trends: CAKN

The climate has a tremendous influence on the landscape and those living on it. Scientists with the Central Alaska Network (CAKN) recognize that monitoring the climate is critical to understanding the condition of park ecosystems. In the past four years, CAKN has added 16 new climate stations across Denali, Wrangell-St. Elias, and Yukon-Charley Rivers. Many of these climate stations were strategically placed at high elevations and in remote areas to supplement existing stations located at low elevations close to populated areas. Though only a few seasons have passed since these new climate stations were installed, network scientists are already discovering interesting information about CAKN’s environment.

In 2006 scientists compared data from the new sites with the older, long-term sites. In most cases it was found that areas of higher elevation had warmer average monthly winter temperatures than lower elevations, due to strong inversions. In addition, it was found that climate extremes were occurring more frequently. 2004 was the warmest summer on record, with observations dating back to 1926 at some locations. Most of the warmest winter, spring, and fall periods at these sites have also occurred within the past 7 years. At the other end of the spectrum, November of 2006 and March of 2007 were the coldest months on record at most locations. There were also record high precipitation and flooding events in August and October of 2006.

Two large scale climate patterns may be affecting conditions in the Central Alaska Network: rapid sea ice loss in the Arctic Ocean and the warm phase of the Pacific Decadal Oscillation.

The decline of sea ice extent in the Arctic Ocean is likely to have serious effects on central Alaska’s air temperatures in the future because it may accelerate warming trends and change climate patterns. Meanwhile, the influence of the Pacific Ocean on subarctic ecosystems is already recognized. Warm sea surface temperatures off the southern coast of Alaska have been increasing overland temperatures for 30 years in what is referred to as the warm phase of the Pacific Decadal Oscillation. These are only two examples of large scale climate patterns that impact CAKN ecosystems, there are many more.

The Central Alaska Network is tracking changes and using climate data to answer questions and support findings in other components of the monitoring effort. Will shallow lakes in Denali’s Minchumina basin continue to dry up? Will spruce trees move ever farther into upland areas? Will caribou find less lichen (a primary food source) as the tundra’s vegetation changes and becomes shrubbier? All complicated questions explained and driven by climate.