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SCISAT-1

Observing the Atmosphere

SCISAT-1 is the first new Canadian scientific satellite since 1971.

It is designed to make observations of the Earth's atmosphere. The instruments on-board will record the spectrum of the Sun, as sunlight passes through the Earth's atmosphere.

SCISAT-1 is scheduled to be launched by the National Aeronautics and Space Administration (NASA) on December 20, 2002.

The scientific mission of SCISAT-1 includes two instruments designed to help our understanding of the chemical processes involved in the depletion of the ozone layer. These are:

• the Atmospheric Chemistry Experiment (ACE)
• Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO)

ACE and MAESTRO

ACE and MAESTRO experiments are part of a large effort by many partners around the world to better understand how temperature, trace gases and levels of aerosol in the atmosphere affect the Earth's protective ozone ACE and MAESTRO will work together with other instruments and missions planned by NASA, the European Space Agency, and other international partners.

SCISAT-1 will allow scientists to collect and analyse a large amount of data. This information will help government leaders to make decisions about international environmental policies such as the Montreal Protocol for the elimination of chlorofluorocarbons (CFCs).

The main purpose SCISAT-1 is to improve our understanding of the depletion of the ozone layer, especially over Canada and the Arctic. The measurements obtained by instruments on board the SCISAT-1 satellite will be combined with data gathered by ground-based, balloon-based and other space-based projects. This data will help scientists predict future trends relating to the ozone layer and its depletion.

Canada Plays an Important Role in the Study of the Ozone Layer

The Government of Canada is working with the international scientific community to study changes in the atmosphere that threaten human health and safety. Environment Canada's studies of the ozone layer are part of a worldwide research and atmospheric monitoring program. 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. They 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 that over the past 20 years the total average ozone level over Canada has declined by six per cent. An added concern is the severe 20-40 per cent ozone depletion observed in the Arctic in early spring.

Being experts in ozone research is very important for Canadians. 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.

As we better understand the mechanisms responsible for ozone losses, we will be able to more accurately predict 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. This is very important for protecting the health and well-being of all Canadians.