Eureka, Nunavut, Canada


Eureka is a research station located at 80°N, 86°W on Ellesmere Island, Nunavut, Canada. It was founded in 1947 as the first out of five weather stations established under Canada-U.S. Joint Arctic Weather Station program. Since the establishment, the station has become an important hub supporting variety of activities in the surrounding area and in the High Arctic in general. Currently it consists of three main areas: the Eureka Aerodrome, the Environment and Climate Change Canada Weather Station (ECCC WS) and the Polar Environment Atmospheric Research Laboratory.

Eureka is the third-northernmost permanent research community in the world. The only two further north are Alert, which is also on Ellesmere Island, and Nord, in Greenland. Eureka is known as the “Garden spot of the Arctic”, with abundant flora and fauna and unique animal life, i.e., jaegers, snow owls, lemmings, Arctic hares, muskoxen, Arctic foxes, Arctic wolves, caribou, and polar bears. The winter temperatures in Eureka can drop below –50°C, and as a result, this keeps the region arid year-round.

Instrument Description


The Eureka Stratospheric Ozone Lidar (SOLID) is situated in the Ridge Laboratory (Ridge Lab) of the Polar Environment Atmospheric Research Laboratory (PEARL). The Ridge Lab is located on a hill 610 m above sea level, ~15 km away by road from the ECCC WS. The laboratory was originally built by Meteorological Service of Canada (MSC, currently ECCC) in 1992 to conduct research specifically related to stratospheric ozone in the High Arctic and was named as Arctic Stratospheric Ozone Observatory (AStrO). In 2005, when PEARL was established, AStrO became its main facility under the name Ridge Lab. Later, two more PEARL facilities were built: 0PAL – near the ECCC WS and SAFIRE – near the Eureka Aerodrome. Since the establishment, PEARL has been operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC), a network of university and government researchers dedicated to studying the changing atmosphere over Canada. It has evolved into a state-of-the-art research institution with a large complement of instrumentation for measuring atmospheric properties from the ground to over 100 km altitude 24/7 year-round.


SOLID was developed and installed on site by Optech Inc. and the lidar group from York University in 1992 (PI Alan Carswell). SOLID along with the double Brewer spectrometer, BOMEM DA8 FTIR spectrometer, and Japanese stratospheric aerosol lidar formed an initial measurement suit at AStrO within the framework of a collaborative program between the MSC and the Meteorological Research Institute of Japan. Stratospheric ozone observations with this differential absorption lidar (DIAL) system began in 1993.


SOLID consists of a transmitter (Excimer laser, laser beam steering and shaping optics, Raman cell), a receiver (1 m Newtonian telescope, polychromator), and control and data acquisition system, together with a computer. The telescope is kept in a room which opens to the sky by a roof hatch (cold room). This room is physically isolated from the main laboratory that houses the rest of the system. SOLID has five measurement channels. The instrument transmits at 308 and 353 nm. It receives elastic returns at both transmitter wavelengths and inelastic returns at 332, 385 nm (in operation since 1994) and 405 nm (in operation since 1999) corresponding to Raman scattering of 308, 353 nm light on nitrogen molecules and 353 nm light on water vapour molecules, respectively. The returns are collected in coadd mode at five-minute intervals. The instrument operates in clear or partially clear sky conditions during the nighttime, which at this latitude occurs continuously from late October to early March, with an emphasis during the polar sunrise (February–March). Besides the stratospheric ozone vertical profiles (10–45 km), SOLID has been used to measure stratospheric and mesospheric temperature (20–80 km) and tropospheric water vapour (1–6 km). The system also has been a proven tool to study gravity waves.

In 2002–2003, SOLID operations were suspended. In 2004–2009, the operations resumed under PI Kevin Strawbridge (ECCC) on a campaign basis (~2 weeks in February-March). The lidar was inoperative in 2010–2016 due to technical and funding issues. In 2015–2016, SOLID underwent a major refurbishment and upgrade which brought the system back to operation in 2017 under PEARL PI James Drummond (Dalhousie University) on the ~4–6 week period leading up to polar sunrise in January–March and up to ~4 week period in October–December. Since 2020 the PI of SOLID and PEARL is Kimberly Strong (University of Toronto).


Carswell, A. I., S. R. Pal, W. Steinbrecht, J. A. Whiteway, A. Ulitsky, and T. Y. Wang. "Lidar measurements of the middle atmosphere". Canadian Journal of Physics. vol. 69, no. 8-9 (1991), pp. 1076-1086. doi: 10.1139/p91-166.

Carswell, A. I., A. Ulitsky, and D. I. Wardle. "Lidar measurements of the arctic stratosphere". Atmospheric Radiation. Ed. by Knut H. Stamnes. Vol. 2049. International Society for Optics and Photonics. SPIE, 1993, pp. 9-23. doi: 10.1117/12.163507.

Pal, S. R., A. I. Carswell, J. Bird, D. P. Donovan, T. Duck, and J. Whiteway. "Lidar measurements of the stratosphere at the Eureka and Toronto NDSC stations". Application of Lidar to Current Atmospheric Topics. Ed. by Arthur J. Sedlacek III. Vol. 2833. International Society for Optics and Photonics. SPIE, 1996, pp. 28-39. doi: 10.1117/12.258164.

Donovan, D. P., H. Fast, Y. Makino, J. C. Bird, A. I. Carswell, J. Davies, T. J. Duck, J. W. Kaminski, C. T. McElroy, R. L. Mittermeiter, S. R. Pal, V. Savastiouk, D. Velkov, and J. A. Whiteway. "Ozone, column ClO, and PSC measurements made at the NDSC Eureka Observatory (80°N, 86°W) during the spring of 1997". Geophysical Research Letters. vol. 24, no. 22 (1997), pp. 2709-2712. doi: 10.1029/97GL52828.

Duck, T. J., J. A. Whiteway, and A. I. Carswell. "Lidar observations of gravity wave activity and Arctic stratospheric vortex core warming". Geophysical Research Letters. vol. 25, no. 15 (1998), pp. 2813-2816. doi: 10.1029/98GL02113.

Moss, A., R. J. Sica, E. McCullough, K. Strawbridge, K. Walker, and J. Drummond. "Calibration and validation of water vapour lidar measurements from Eureka, Nunavut, using radiosondes and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer". Atmospheric Measurement Techniques. vol. 6, no. 3 (2013), pp. 741-749. doi: 10.5194/amt-6-741-2013.

Tikhomirov, A. B., G. Farhani, E. M. McCullough, R. J. Sica, P. F. Fogal, T. Leblanc, and J. R. Drummond. "Ozone Measurements Using the Refurbished Eureka Stratospheric Differential Absorption Lidar". Canadian Journal of Remote Sensing. (2019), pp. 1-21. doi: 10.1080/07038992.2019.1651195.

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