An evaluation of Doppler lidar wind profiles at the Iqaluit and Whitehorse Supersites

Environment and Climate Change Canada (ECCC) commissioned two supersites to provide automated and continuous observations of altitude-resolved winds, water vapour, clouds and aerosols, visibility, radiation fluxes, and precipitation as part of the Canadian Arctic Weather Science (CAWS) project. The supersites are located in Iqaluit (64^oN, 69^oW) and Whitehorse (61^oN, 135^oW). The benefit of integrated measurement systems at the supersites are being investigated to: 1) recommend the optimal cost-effective observing system for the Canadian Arctic that can complement existing radiosonde observations, 2) provide enhanced meteorological observations to evaluate numerical weather prediction (NWP) forecast model performance during the World Meteorological Organization’s Year of Polar Prediction (YOPP), and 3) assess the impact of assimilating lidar observations into the NWP model. This presentation will describe the suite of remote-sensing instruments at the supersites and present an evaluation of Doppler lidar wind profile measurements by comparing them with coincident radiosonde observations and operational NWP model output from ECCC’s Global Environmental Multiscale Model (GEM-2.5 km and GEM-10 km). Results indicate good agreement between the Doppler lidar and the radiosonde, with the lidar exhibiting an average bias of -0.48 m/s compared to the sonde. Comparisons to the NWP models also indicate good agreement with an average bias of < 0.7 m/s for GEM-2.5 km; as such, the feasibility of assimilating these lidar observations into the NWP model to reduce forecast error will be discussed.