Raw backscatter data were collected from a CT25K ceilometer. A ceilometer is a device that uses a laser or other light source to determine the height of a cloud base. Ceilometers can also be used to measure the aerosol concentration within the atmosphere. Sampling took place from July to November 2009 in the southern Beaufort Sea and the Amundsen Gulf (Canadian Arctic) during the CFL cruise onboard the CCGS Amundsen icebreaker. The Circumpolar Flaw Lead System Study (CFL) is an IPY-funded project. Data were collected (1) during the ship transit, (2) set transects, (3) at several stations where we stayed 24 hours, and (4) at multi-day drift stations. The instrument was running continuously during the CFL project, with only minor interruptions for maintenance activities.

Raw backscatter data were collected from a Vasaila CT25K ceilometer. A ceilometer is a device that uses a laser or other light source to determine the height of a cloud base. Ceilometers can also be used to measure the aerosol concentration within the atmosphere. Sampling took place from in the Southern Beaufort Sea and the Amundsen Gulf (Canadian Arctic) during the ArcticNet / BP Partnership cruise onboard the CCGS Amundsen. Data were collected (1) during the ship transit, (2) set transects, (3) at several stations where we stayed 24 hours, and (4) at multi-day drift stations. The instrument was running continuously during the cruise, with only minor interruptions for maintenance activities.

Raw backscatter data were collected from a CT25K ceilometer. A ceilometer is a device that uses a laser or other light source to determine the height of a cloud base. Ceilometers can also be used to measure the aerosol concentration within the atmosphere. Sampling took place from May to October 2016 in the Beaufort Sea, Northwest Passage, Baffin Bay (Canadian Arctic) during the cruise onboard the CCGS Amundsen icebreaker. The CT25K is designed to detect three cloud layers simultaneously up to around 18 000 ft, given suitable conditions. Besides cloud layers, it detects whether there is precipitation or other obstruction to vision. Output files were created hourly by the system and are in ASCII format.