Cold Air Pooling and Changing Microclimate in Arctic Lapland: Downscaling the Impacts of Climate Change

A field network of 65 sensors was installed surrounding the Kevo Sub Arctic Research Station in northern Finland in September 2007. It is still in operation. Sensors measure air temperature and relative humidity. Other observations (intermittent) have included wind, snow properties and solar radiation.

A network of 65 weather stations provides local scale detail on changing microclimates in northern Finland, as a response to climate change. Additional surveys of the snowpack every winter (usually March) provides extra detail on changing snow conditions.

At night cold air sinks into the Kevo valley and it can be over 20degC colder than the upper slopes. This separates the microclimate of the valley from the larger scale climate and has profound consequences for the ecosystem. In particular temperatures below -35degC are critical for preventing outbreaks invasive species such as the Epirrita Autumnata moth which can defoliate birch trees. Changes in cold air drainage mean that there is a large difference in the frequency of cold temperatures both between years and between sites.