Canada's New Lidar Network for Measurements of Clouds, Aerosols, Forest Fire Smoke, and Volcanic Ash

We are assembling a network of automated lidars with the capability to measure aerosol type and discriminate liquid water versus ice using polarization of the lidar return signal. These lidars will be installed at key nodes in the Canadian Anchor Sites for SAtellite Validation (CASSAVA) network including 2 sites which are small urban islands in rural settings (London; Sherbrooke), an urban environment (Toronto), a marine environment (Halifax), and at the Canadian Network for the Detection of Atmospheric Change (CANDAC) Polar Environment Atmospheric Research Laboratory (PEARL) at Eureka, Nunavut in the high Arctic. The lidar network will be used to quantify the impact of atmospheric particulates on the interpretation of ozone trends measured by surface-based, total-column instruments. Adding the profiling information from the lidars will allow improved estimates of ozone trends in rural, urban, and marine locations in southern Canada, as well as in the high Arctic. The ability of the lidars to distinguish particle type will allow studies of the formation of clouds and fog, and allow us to improve models of cloud and fog formation by measuring whether the water in clouds is liquid, ice, or mixed. The lidars will also be critical to better understanding the link between surface pollution measurements (such as PM2.5), columnar measurements (AEROCAN/AERONET) and satellite (columnar) retrievals. We will give particular attention to the composition and transport of forest fire smoke. We expect the network to be fully operational within the next year, and the lidar measurements will be made available to the scientific community.