AWI's MARL-instrument is a mobile backscatter lidar that is used at various locations as well as aboard the research vessel Polarstern to measure Aerosol and clouds in the upper troposphere and lower stratosphere. In 2000 two field-experiments have been conducted within the European INCA 2000-project (Interhemispheric differences in cirrus cloud properties by anthropogenic emissions). The first one took place in the southern hemispheric midlatitudes, in Punta Arenas/Chile (53.12°S, 70.88°W) and the second campaign followed in September 2000 in Prestwick /Scotland (55.51°N, 4.60°W). The main objective of these activities was to collect Lidar data on cirrus clouds from clean (Punta Arenas) and polluted (Prestwick) areas. During the four weeks of the campaigns, around 80 h of Lidar measure-ments were gathered at each location, covering different types of cirrus clouds as well as background aerosols. A comparison of the two datasets reveals similarities as well as differ-ences in the measured cirrus cloud properties.During the first campaign in Punta Arenas, direct overpasses of the Falcon aircraft, equipped with a number of Aerosol and cloud particle instruments were performed. Comparisons show good agreement in terms of backscatter coefficients calculated from the insitu data compared with those measured by the lidar.