News

Energetic particle precipitation, in which high-energy electrons and protons from the Sun and magnetosphere hit Earth's upper atmosphere, results in the production of nitrogen oxides (NO_x) in the mesosphere and lower thermosphere. Under the right weather conditions, NO_x can descend into the stratosphere, where it destroys ozone. The authors note that 2009 is the second time on record in recent years when abnormal weather conditions led to increased descent of NO_x in the polar region. They suggest that this may indicate that changes are occurring in the atmosphere and point to a need for better understanding of the interaction between meteorology and space weather.

The Canadian Aeronautics and Space Institute has announced the recipients of the 2009 CASI Senior Awards. The 2009 Alouette Award for outstanding contributions to advancement in Canadian space technology, applications, science and engineering goes to leaders of the development of the outstandingly successful Canadian SCISAT satellite.

Operating well beyond its planned lifetime of two years, Canada's SCISAT celebrates its fifth birthday today in service to science and Canada.

Carbonyl sulfide (OCS), the most abundant sulfur-containing gas in the atmosphere, is important to biological nutrient cycles. Using OCS vertical profiles retrieved by Canada's Atmospheric Chemistry Experiment (ACE) satellite, Barkley et al. (2008) examine the seasonality of global OCS distributions in the upper troposphere and stratosphere. Because tracer gases in the stratosphere are linearly correlated, the authors used concurrent ACE measurements of certain chlorofluorocarbons to derive a robust estimate of the stratospheric lifetime of OCS.

It was used as a chemical weapon in the trenches in the First World War, but nearly a century later, new research by an international team of scientists has discovered that phosgene is present in significant quantities in the atmosphere.

A surprising new study finds that high-speed winds above the northern hemisphere have a much greater impact on ozone levels than was previously thought.