Arctic tropospheric aerosols and clouds in the polar night season observed by a lidar at Eureka, Canada

Vertical profiles of tropospheric aerosols and clouds were observed with a lidar at Eureka (80 degrees N, 86 degrees W) in the Canadian high Arctic. The observation periods were February, March and December 1993, and January and February 1994. Observations were also performed from December 1994 to March 1995. Vertical distributions of aerosols and cloud particles are not easy to observe in the Arctic region especially in the polar night season. The lidar observations showed us the first overviews of Arctic tropospheric particle characteristics in mid-winter. Ice crystals were often observed, which correlate very well with the relative humidity over ice that was observed by routine meteorological observations by radiosonde. Particle layers in a very dry environment were sometimes observed.