The Summit Station in Greenland is located (72° 36’N, 38° 25’W, 3250m), atop the Greenland Ice Sheet making it a unique location for a cloud– atmosphere observatory. The station is about 400 km from the east and west coastlines and more than 1,000 km from the southwest and southeast coasts, from which most of the flow impinging on Summit originates, making it a distinctly continental environment. Additionally, the high altitude leads to extremely cold and dry conditions and a relative compression of the troposphere above the ice sheet.