The Atmospheric Chemistry Experiment (ACE) is a satellite mission on board the Canadian satellite SCISAT that takes measurements of the Earth's atmosphere. Originally planned to have a two-year lifetime, ACE performs flawlessly 20 years on.
ACE uses Fourier transform infrared spectroscopy of sunlight during sunrise and sunset to determine the abundance of 46 atmospheric molecules associated with ozone depletion, air pollution, and climate change.
All these mission data products are produced in the Chemistry Department at the University of Waterloo at the ACE Science Operations Centre (SOC). The SOC analyzes the ACE infrared spectra and distributes their data products to hundreds of users around the world.
Dr. Peter Bernath is the Mission Scientist, which involves the collaboration of members from several universities, industries and other organizations in Canada and around the world. Funding for the ACE mission is primarily provided by the Canadian Space Agency.
With 46+ atmospheric molecules measured over 20 years, ACE stands as Canada's most successful scientific mission.
SCISAT was launched on August 12, 2003 and has been measuring data since February, 2004. The SCISAT mission originally had a 2-year lifetime, but has far exceeded that!
The most recent ACE-FTS dataset, version 5, has over 20 years of atmospheric data for 46 molecules, plus isotopologues and line-of-sight winds.
SCISAT has orbited the Earth over 110,000 times!
News
ACE featured in "Fifth edition of Spectra of Atoms and Molecules" textbook
The fifth edition of Spectra of Atoms and Molecules (Oxford University Press, 2025) is an invaluable companion for the ACE mission. For example, the book has a chapter on spectra of clouds and aerosols based on ACE data.
ACE publishes new processing version v5.3!
ACE-FTS version 5.2 processing ended on Nov. 30, 2024 and has been replaced by v5.3. This version change was required because of a change in processing computers. A small change was also made in the retrieval code, which has minimized the number of “spikes” in the VMR profiles near 30 km. As in v5.2, v5.3 removes any occultations with spikes at 30 km. About 1500 occultations have been recovered in v5.3. Processing for the Imagers has not changed. ACE-FTS v5.3 winds will be available soon. V5.3 is therefore the current and complete ACE-FTS and Imager processing version and can be viewed at our ACE-FTS v5.3 database. More details are available in the ACE documents.
ACE in the news: "Big success for Canadian science: University of Waterloo scientists use satellite to measure greenhouse gas"
The Waterloo Region Record published a news article on ACE!
"While other studies measure the gas on the ground or much lower in the atmosphere, this study by the university’s “Atmospheric Chemistry Experiment” (ACE) research group is the only one which uses a satellite to measure it between 11 and 25 kilometres above the globe."
Events
51st ACE Science Meeting
The next ACE Science Meeting will be held as a hybrid in person and online meeting, at the University of Waterloo and via WebEx. This meeting will focus primarily on the achievements, current work, and future plans of the ACE (SCISAT) satellite mission. In addition to the usual speakers from ACE, speakers from other missions, space agencies, modelling groups, and validation teams are invited to participate. Potential new users of ACE data are particularly encouraged to attend.
Time: 9:00 AM - 5:00 PM
Place: University of Waterloo (Room To Be Confirmed)
Online meeting via WebEx