Background

SCISAT was launched by the National Aeronautics and Space Administration (NASA) on August 12, 2003 at 10:10 p.m. EDT from Vandenberg Air Force Base, California. On February 4, 1999 the Government of Canada announced the selection of the Atmospheric Chemistry Experiment (ACE) as the scientific mission of SCISAT.

The Atmospheric Chemistry Experiment (ACE)

The major scientific goal of the Atmospheric Chemistry Experiment (ACE) mission is to measure and understand the chemical processes that control the distribution of ozone in the Earth's atmosphere, especially at high latitudes. The data that will be recorded as SCISAT orbits the Earth will help Canadian scientists and policy makers to assess existing environmental policy, and to develop protective measures for improving the health of our atmosphere and preventing further ozone depletion. The ACE mission is designed to last at least two years.

The Mission Scientist is Dr. Peter Bernath from the Department of Chemistry at the University of Waterloo. He heads a Science Team that includes Canadian scientists as well as scientists from the United States, Belgium, Japan, France and Sweden. Participating organizations include Trent University, University of Toronto, University of Saskatchewan, University of Waterloo, University of Western Ontario, York University, Université Laval, University of Denver, Nagoya University (Japan), Belgian Federal Office for Scientific, Technical and Cultural Affairs, Free University of Brussels (Belgium), Swedish Environment Research Institute, Centre National d’Études Spatiales (CNES/France), the Meteorological Service of Canada (Environment Canada), ITT Industries (US), and NASA Langley. NASA's Earth Sciences Enterprise and Institut d’Aéronomie Spatiale de Belgique are also Contributing Partners.

The SCISAT satellite

Here are some quick facts about the new satellite:

ACE-FTS Onboard SCISAT

The ACE mission consists of a Fourier Transform Spectrometer (ACE-FTS) instrument and the Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) instrument. Both instruments are designed to gather information on the chemical processes occurring in the ozone layer, approximately 8 km to 50 km above the Earth’s surface.

Mission Science Objectives

The principal goal of the Atmospheric Chemistry Experiment (ACE) mission is to investigate the chemical processes that are involved in the distribution of ozone in the atmosphere. The ACE mission will work in conjunction with other instruments and missions planned by NASA, the European Space Agency, and other international partners over the next decade to gain a better understanding of the chemistry and dynamics of the atmosphere that affect the Earth’s protective ozone layer. The analysis of the large amount of data that will be collected will lead to a more informed assessment of international environmental policies such as the Montreal Protocol for the elimination of chlorofluorocarbons (CFCs).

The overall objective of the ACE mission is to improve our understanding of the depletion of the ozone layer, paying close attention to what is happening over Canada and the Arctic. The measurements obtained by the ACE-FTS and MAESTRO instruments will be combined with data gathered by ground-based, balloon-based and other space-based projects in order to obtain the best possible information to predict future trends relating to the ozone layer and its depletion.

The Government of Canada is working with the international scientific community to determine the extent and causes of atmospheric changes that threaten human health and safety. Sound scientific data is essential to finding effective solutions to problems such as depletion of the ozone layer and climate change. Environment Canada’s studies of the ozone layer, which began over 50 years ago, support a worldwide research and atmospheric monitoring program. And through the leadership of the Canadian Space Agency, Canada is also involved in research studying the ozone layer from space.

Canadian scientists are world leaders in studies of the atmosphere related to ozone depletion. The Canadian Space Agency is flying another Canadian instrument called OSIRIS on Odin, a Swedish satellite launched on February 20, 2001. This instrument also measures the global amount of ozone and its findings will be compared with the ACE mission results.

The Canadian Space Agency also launched a prototype OSIRIS instrument in April 1998 on a rocket from Churchill, Manitoba, and another similar instrument on the MANTRA balloon from Vanscoy, Saskatoon, in August 1998, August 2000 and September 2002, to help our understanding of this complex atmospheric region.

Canada’s important role in the study of the ozone

The Canadian Space Agency, both in the past and now with the ACE-FTS and the MAESTRO instruments, continues to provide opportunities for Canadian involvement in space-based ozone research. Canadian scientists first started measuring ozone levels over Canada in the 1930s. In the 1980s this continued research led to the discovery that the ozone layer over Canada was being depleted. Scientists have found indications that over the past 20 years the total average ozone level over Canada has declined by six per cent. Of additional concern is the severe 20-40 per cent ozone depletion observed in the Arctic in early spring.

Maintaining and enhancing Canada’s expertise in ozone research is crucial. Canada’s northern geography makes it one of the most vulnerable countries in the world when it comes to the effects of ozone depletion in the Arctic region. Since the ozone layer is responsible for protecting us from harmful UV-B rays from the sun, any reduction in the layer is cause for alarm. Increased exposure to UV-B rays results in higher numbers of cases of skin cancer, eye damage and weakened immune systems.

Advances in our understanding of the mechanisms responsible for ozone losses will tell us whether an ozone "hole", such as the one found in Antarctica, is likely to occur above Canada in the future. More importantly, continued research, such as that which will be carried out on the ACE mission, will also help us identify how the ozone layer can be restored and preserved, thus protecting the health and well-being of all Canadians.