K. Strong (U. Toronto) – Bruker 125HR (0.0027 cm-1 resolution, mid-infrared), installed in July 2006. Direct-sun solar absorption spectra are collected in a semi-automated operation on clear-sky days from polar sunrise (approx. February 20) until polar sunset (approx. October 20). Three intercomparison campaigns with the Bomem DA8 FTIR (see above entry) were conducted prior to the removal of the DA8: February to April 2007, February to April 2008, and July 2007. Alternating mid-infrared NDACC and near-infrared TCCON measurements on a semi-daily basis since 2010. Operations in 2012 and 2013 were affected by budget cuts. New funding has enabled operations through to 2019.

T. Nagai (MRI) and O. Uchino (MRI) – Nd:YAG Lidar (1064 and 532 nm; dual polarization) deployed in February 1993. Operations were winter only. Operations were expanded to allow for tropospheric retrievals. Operations suspended after spring 2002. Data exist in the database for the two winters spanning 1993 – 1995.

J. Drummond and A. Tikhomirov (Dalhousie U.) – DIAL system deployed in February 1993 for winter season, nighttime only operations. Operation suspended for 2002 and 2003. Operations resumed in 2004-2009 on a campaign basis schedule (~2 weeks in February-March). Operation suspended for 2010-2016 due to technical and funding issues. Operations resumed since 2017 on the approximately 4-6 week period leading up to polar sunrise in January-March and ~2 week period in October-November. The system has five detection channels: 2 Rayleigh channels (308 and 353 nm), 2 Raman channels to improve the ozone profile in the presence of aerosols (332 and 385 nm), and 1 Raman channel for water vapor (405 nm). Funding is currently in place for operations through to 2019.   Early data exist in the database under PI Carswell for 1993-1998 and resumed under PI Strawbridge for 2004-2009 and under PI Drummond since 2017.