When it is dark over Ny Ålesund, Svalbard, a bright green laser beam can be seen quite often, shooting from the AWIPEV Arctic Research Base observatory towards the sky. This beam belongs to “KARLi” the Koldewey Aerosol Raman Lidar, run by the Alfred Wegener Institute for more than 25 years, which contributes to long-term, atmospheric aerosol measurement records.

With this system scientists investigate the atmosphere and look for thin clouds and aerosols. Aerosols and clouds, and their interactions, are major unknowns in the radiative balance of the Arctic climate system – that is the balance between how much energy is received and given out. This photo was kindly provided by Gregory Tran, who was the AWIPEV Station Leader for the Overwintering period 2019-2020.