Ceilometer and Lidar Measurements of Atmospheric Trends, Coupling Between Atmospheric Layers, and Atmospheric Particulates

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The investigations proposed in this Discovery Grant will improve our understanding of trends in four key components in Earth's climate: temperature, water vapour, ozone and aerosols such as forest fire smoke particles. The trends will be assessed from measurements primarily by lidars (laser radars), which can measure these quantities from the surface throughout the atmosphere to altitudes of 110km. Measurements available for these studies include those from a lidar located near The University of Western Ontario, a ceilometer (a compact, automated lidar system) located on the Western campus, a water-vapour aerosol and temperature lidar, RALMO, located in Switzerland, and DIAL ozone and Raman-Rayleigh lidars in Eureka, Nunavut and the Observatory of Haute Provence in France. These lidars are part of the Network for Detection of Atmospheric Climate Change (NDACC).My diverse group of 7 graduate students works in all facets of atmospheric lidar techniques, from hardware design to developing advanced processing techniques for the retrieval of atmospheric quantities. These techniques can be applied to existing as well as new measurements, and will be made available to the scientific community, in particular our colleagues in NDACC, an international program of atmospheric sensors dedicated to studying climate change in the lower and middle atmosphere. We will also study stratosphere-troposphere exchange, whereby air in the lower part of the atmosphere, the troposphere, is lifted into the stratosphere, where it can be transported great distances before descending back into the troposphere. Such events can cause polluted middle latitude air to be mixed into the clean Arctic atmosphere in Eureka.I am also actively pursuing the use of low-cost ceilometers (automated lidars) for measurements that will improve our understanding of clouds, pollutants, forest fire smoke, and volcanic dust. Our ceilometer is part of an international collaboration of 20 member nations developing a measurement network of calibrated ceilometers and lidars. Dust and smoke particles can travel a great distance, and this summer our instrument in London, Ontario measured smoke from fires in Alberta and British Columbia. Measurements by our collaborators showed some of this smoke was eventually transported as far as Europe. In summary, I propose a program to improve our understanding of weather and climate using high temporal-spatial resolution lidar measurements from the surface to the edge of space. In addition to scientific studies, the research will be applied to improving our understanding of fire smoke and volcanic ash transport, including real-time measurements/monitoring of situations which can affect health (via warnings of poor air quality) and safety (via warnings of lofted particulates which can affect aircraft flight corridors).