Use of airborne lidar to determine aerosol sources and movement in the Lower Fraser Valley (LFV), BC

A major oxidants field experiment (Pacific ʹ93) was carried out in Vancouver, British Columbia, in July/August 1993. The purpose of the experiment was to provide data on the three-dimensional extent and movement of pollutants in a complex topographic regime so that predictive pollutant models could be assessed. As part of the study, 1.064 μm downward pointing lidar was flown on the National Research Council of Canada (NRCC) Convair 580 aircraft. These data have been used to visualize the aerosol pollutant structure throughout the lower Fraser Valley. While the majority of the pollution in the valley is from the urbanised sector around Vancouver, there are at least seven additional point source emitters which impact the valley in a significant way. The data are compared with in situ particle probe data from the aircraft when flying at low level and with surface sensors. Aerosol backscatter ratio at 500 m altitude is about 25–60% larger than predictions from a Mie scattering model using the in situ particle probe size distributions.