The Eureka stratospheric Lidar (80N, 86.25W, 610 m) is located in the Polar Environment Atmospheric Research Laboratory (PEARL), formerly known as the Arctic Stratospheric Observatory (AStrO) laboratory, situated near the Environment Canada Eureka weather station. The laboratory is located on a 600 m hill overlooking Slidre fjord on Ellesmere Island, at a sufficient altitude to generally be in the free troposphere. PEARL operates year-round, but the Lidar is used primarily during the dark winter months with an emphasis during the polar sunrise (late February to early March).
Eureka's climate is high arctic and it is known as the "Garden spot of the Arctic", with abundant flora and fauna and unique animal life (musk oxen, Arctic wolves, Arctic foxes, Arctic hare, lemmings and even the odd polar bear). The winter temperatures can reach to -50 ºC, and as a result, keep the region arid year-round.
The stratospheric Lidar became operational in 1992 and has been used to measure the stratospheric ozone concentrations (7-50 km) and middle atmosphere (10-70 km) temperature profiles at 300 m resolution during the arctic winter. It also measures atmospheric water vapour in the upper troposphere and lower stratosphere. The Lidar transmitter consists of a 308 nm Excimer laser and a Raman cell filled with hydrogen that converts a portion of the laser light to 353 nm. The receiver includes a 1 m Newtonian telescope, which directs the returned photons into one of 5 channels: 308 nm (ozone absorption), 332 nm (nitrogen Raman return from 308 nm), 353 nm (no ozone absorption), 385 nm (nitrogen Raman return from 353 nm) and 406 nm (water vapour Raman return from 353 nm). Its remote northern location and elevation mitigate the necessity to include aerosol measurements in the ozone calculations.
The Eureka NDACC principal investigator is Kevin Strawbridge (Environment Canada - Kevin.Strawbridge@ec.gc.ca). Dr. Strawbridge currently operates a tropospheric ozone and aerosol system at Egbert, Ontario and CORALNet, an aerosol Lidar network across Canada (www.coralnet.ca), along with other airborne and mobile Lidar laboratories. His main research interests are directed at understanding more about the optical properties and transport mechanisms of aerosols and ozone and their impact on climate, visibility and air quality.