AMC's climate research focuses on causes of and changes to the Northeast's sub-alpine forest and alpine plant communities. AMC is examining the apparent resistance and resiliency of these ecosystems to climate change and air pollution. Research is done collaboratively with partner universities and other research oriented organizations like the Mount Washington Observatory. AMC's Joe Dodge had the insight to initiate daily weather measurements in the 1930's on Mount Washington's summit and at Pinkham Notch. Today these are some of the best long-term climate data sets for mountains in the world, and important tool for studying climatic trends and their impact on northeastern mountain ecosystems.
In New Hampshire's Pinkham Notch, snow melt is occurring 2 weeks earlier today than in the 1930s, while the timing of snow melt on Mount Washington's summit has not changed.
Over the last 80 years Mount Washington's summit and Pinkham Notch have warmed. Alpine plants in new Hampshire's Presidential Range are flowering earlier than in the 1930s, but only by 1 -2 days. At lower elevations flowering has advanced by weeks. (Kimball et al., 2014)
Mount Washington's summit has a climate record that only partially follows lower elevations. Daily solar heating and cooling cycles stratify (separate) air masses with elevation, exposing higher elevations to different air masses on a daily basis. This is why mountain tops may experience more long distance air pollutants (acidic rain and cloud, ozone) than lower elevations. Moist air masses are forced upwards by mountains, causing clouds to form. Mount Washington is one of the cloudiest places in the world.
The Northeast's montane spruce-fir forest and alpine ecosystems today are isolated "islands in the sky", relics that survived a major warming period about 5,000 to 9,000 ago. These regions may be important refugia for montane ecosystems again in a warming climate.
Northeastern alpine ecosystems are some of the lowest in the world for these latitudes. The alpine and forest interface line varies by over 2,000 feet in elevation. Trees can and do grow at the highest elevations.
Topographic exposure and elevation are important. High frequency of clouds and winds result in frequent icing events. Blowing snow and ice particles are very abrasive. More so on ridges and summits. These events mechanically degrade and inhibit trees from overgrowing the region's alpine ecosystems. Growing season temperature is likely not the dominant factor.
The source of mountain air pollutants and climate changing greenhouse gases are the same, the combustion of fossil fuels.
Kimball, Davis, et al. (2014). Limited Alpine Climatic Warming and Modeled Phenology Advancement for Three Alpine Species in the Northeast United States. American Journal of Botany
Murray, Kimball, et al. (2009). A 16-year comparison of fine particle and aerosol strong acidity at the interface zone (1,540 m) and within (452 m) the planetary boundary layer of the Great Gulf and Presidential-Dry River Class I Wildernesses on the Presidential Range, New Hampshire USA. Atmospheric Environment
Seidel, Kimball, et al. (2009). Evidence of climate change declines with elevation based on temperature and snow records from 1930s to 2006 on Mount Washington, New Hampshire, USA. Arctic, Antarctic and Alpine Research