Atmospheric and Climate Science Directorate

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Understanding the Chemical Process that Affect Ozone Layer

Space-based Measurements using Balloons and Satellites

For over 30 years, scientists within the Meteorological Service of Canada MSC have been sending probes into the stratosphere to gain an understanding of the chemistry related to the formation and destruction of the ozone layer - a problem that still has not been fully solved. The first experiments, in the 1970’s and 1980’s, used highaltitude balloons and rockets. Since then, MSC researchers have flown experiments aboard NASA space shuttles and on high-altitude NASA research aircraft.

Large-payload balloon flights were conducted as part of the Middle Atmosphere Nitrogen Trend Assessment MANTRA.The MSC, the Canadian Space Agency, and several universities were jointly involved in this project.

In 1998, 2000 and 2002, these same scientists teamed up with the Canadian Space Agency, several universities, and industry to launch large-payload balloons to continue studying the stratosphere to determine what changes have taken place over the last 25 years. MSC’s next step in understanding ozone depletion chemistry is the recently launched SCISAT 1, Canada’s first scientific satellite in over 30 years. MSC scientists, with the help of the Canadian Space

SCISAT 1 is the first Canadian scientific satellite launched in over 30 years. Photo is from NASA’s image library

Agency, universities and industry, designed one of the two Canadian instruments selected to be part of this historic flight. This instrument, called MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation), measures stratospheric and tropospheric ozone, aerosols and other trace species. It will provide important new information on aerosols and chemistry in the stratosphere and upper troposphere by looking through the Earth’s atmosphere at the sun as it rises and sets. The information provided by this experiment will give scientists a greater understanding of why the stratospheric ozone layer is not rebounding as quickly as expected following the implementation of the Montreal Protocol and the Vienna Convention on Substances that Deplete the Ozone Layer. Such space-based science is an important tool in ensuring that Canadian environmental policy is founded on the most up-to-date scientific findings.

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The chemistry related to the formation and destruction of the ozone layer is affected by the air flow in the stratosphere. Air enters the stratosphere at the equator. The hot surface generates strong upward currents and thunderstorms.The air then moves northward towards the poles where it subsides.

“MSC’s expertise in making highly accurate and precise spectral measurements has contributed greatly to the development of both ground-based and spacebased instruments, providing critical information on the accuracy of ozone measurements around the world.”
Jim Drummond Associate Chair
Graduate Studies
Department of Physics University of Toronto

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