Seminar: Dr. Kaley Walker


Burnside Hall Room 934, 805 rue Sherbrooke Ouest, Montreal, QC, H3A 0B9, CA

Please join us as we welcome Dr. Kaley Walker, a Professor in the department of Physics at the University of Toronto seminar titled "Using Spectroscopy to Measure Atmospheric Composition with the Atmospheric Chemistry Experiment - A two-year mission that is still going after thirteen years!". Coffee will be served.


Reliable chemical composition measurements are essential for monitoring and to understand changes occurring in the Earth's atmosphere due to ozone recovery, climate change and pollutant emissions. Altitude-resolved data are a necessary part of this composition data set because many processes occur at specific altitudes or over limited vertical length scales. Solar occultation has proven to be a very effective technique for measuring profiles of atmospheric trace gases and aerosols, capable of tracking long-term changes.M/p>

This presentation will describe the results from the Canadian-led Atmospheric Chemistry Experiment (ACE), a scientific satellite mission using the solar occultation technique. In orbit since 2003, the SCISAT/ACE satellite uses infrared and UV-visible spectroscopy to investigate the chemistry and dynamics of the Earth's atmosphere. The two instruments, ACE-FTS and ACE-MAESTRO, have been making regular solar occultation observations for more than twelve years and, from these measurements, deriving altitude profiles of over 30 different atmospheric trace-gas species, temperature and pressure. This presentation will discuss recent scientific and validation results from ACE-FTS.

For information about the Atmospheric Chemistry Experiment including publications, climatological data sets and publicly available profiles, please visit the ACE website: