The University of Toronto Atmospheric Observatory (TAO), located at 43.66 N, 79.40 W, and 174 m above sea level, is ideally located for long-term studies of the atmosphere at mid-latitudes. TAO was established in 2001, and is located on the 16th floor of the Burton Tower of the McLennan Physical Laboratories located on the St. George Campus in downtown Toronto.
A high-resolution Fourier transform infrared spectrometer (FTS) is the primary instrument at TAO and has been operating since October 2001, with daily measurements since May 2002. It is used to record solar absorption spectra on a daily basis for long-term measurements of stratospheric and tropospheric trace gases, studies of urban pollution, and mid-latitude atmospheric chemistry and satellite data validation.
The TAO FTS meets the requirements of the international Network for the Detection of Atmospheric Composition Change (NDACC), allowing the absorption lines of about 30 molecules and isotopes, including ozone, chlorine reservoirs, nitrogen- and carbon-containing compounds, and dynamical tracers to be distinguished. TAO was approved as a Complementary Measurement Station by the NDACC in March 2004, based on the results of a refereed algorithm and data comparison exercise.
Several other instruments are also installed at TAO, including a UV-Visible grating spectrometer, a Brewer ozone spectrophotometer, a weather station, a SAOZ instrument, a VLF lightning detector, and a custom-built Suntracker.
TAO has received support from the University of Toronto, CFI, ORDCF, CRESTech, NSERC, ABB Bomem, CFCAS, and PREA.