Situated about 200 km north from the Arctic Circle in Lapland lies ICOS station Pallas Sammaltunturi, a place where the sun does not set in summer nor rises above the horizon in winter.
Situated about 200 km north from the Arctic Circle in Lapland lies ICOS station Pallas Sammaltunturi, a place where the sun does not set in summer nor rises above the horizon in winter.
The station stands on an Arctic hill covered by Alpine tundra. The tree line starts at about 300 metres down from the top of the hill. However, the rise of the annual average temperature by 2 degrees Celsius has caused the tree line to advance upward over time.
At the site, scientists breathe the cleanest air in Europe but Arctic regions are especially sensitive to the air pollutants and greenhouse gases which contribute to climate change. In Sammaltunturi, 565 metres above the sea level, ICOS is observing clean northern air coming from the Norwegian Barents Sea and the Northern Atlantic to set up a basis for measurements.
Occasionally, southern winds from more densely populated European areas reach the station, allowing it to estimate the amount of air pollutants and greenhouse gases being transported to the Arctic area.