Dust-related ice formation in the troposphere (DRIFT)

• Applicant: Privatdozent Dr. Albert Ansmann
• Subject Area: Atmospheric Science
• Term: from 2005 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5453552

The project deals with long-term observations of heterogeneous ice formation in freetropospheric clouds with a unique temperature/humidity/aerosol Raman lidar. Such long-term observations in natural cloud environments (in contrast to hill top environments) are completely missing, but are strongly needed to significantly improve our understanding of the interaction of aerosols and clouds in the troposphere and to guide cloud model developments. The focus is on ice formation in altocumulus/stratus (3-9 km height range) affected by Saharan dust. However, the influence of other aerosols (aged urban haze and forest fire smoke), of cirrus (ice crystal virga) and gravity waves (evaporation of drops) on ice formation in altocumulus/stratus will be investigated as well. Work packages include lidar observations over two years during Saharan dust outbreaks and during dust-free conditions (background or reference cases), lidar data analysis, discussion of case studies and of the main findings, as well as the re-analysis of cloud observations sampled with the Raman lidar at Leipzig in the framework of the German lidar network (1997-2000) and EARLINET (2000-2003).

• DFG Programme: Research Grants