Lidar measurements of aerosol impacts, transport and mixing on Earth and Mars

The Atmospheric-Optics Laboratory at Dalhousie University builds and uses lidar (laser radar) systems for atmospheric research. Our programme is divided into three main projects: 1) The Dalhousie Raman Lidar observes continental outflow from pollution and forest fires. The aerosols are used as passive tracers of atmospheric motions and are interpreted with the help of models to gain insight into transport and mixing processes. 2) Atmospheric research will be pursued in the High Arctic at Eureka during the International Polar Year (IPY) and beyond as part of the Canadian Network for the Detection of Atmospheric Change (CANDAC). A new lidar is being built to study the impact of clouds, aerosols, and water vapour on the radiative environment, which is central to the climate problem. 3) The Phoenix Mars Scout project that will land a lidar on Mars in 2008. These measurements will provide unique "first-time" information on the vertical distribution of aerosols and clouds in the Martian atmosphere. The Dalhousie Raman Lidar was built from scratch and then used for observations over the past two years. The measurements have highlighted the regular occurrence of pollution episodes transported from distant sources, and also the injection of aerosols high into the troposphere by forest fires. We propose to upgrade the lidar by the adding a water vapour profiling capability, which will provide a clearer picture of what is happening in the boundary layer and at tropopause heights. Data from intensive summertime measurement campaigns will be interpreted with the aid of the FLEXPART Lagrangian particle dispersion model. Construction of the new lidar for Eureka will be based on our experiences with the Dalhousie Raman lidar, and will have a more extensive set of capabilities. The work will require travel to the Arctic and contributions to the CANDAC Clouds, Aerosols and Radiation Theme. Students will be involved in every facet of each of these activities.