About

The Institute of Space and Atmospheric Studies (ISAS) was formed in 1956 to study the aurora (northern lights), the related disturbances in the upper atmosphere and ionosphere, and the effects of solar activity upon climate. Since that time members of the institute have expanded the world’s knowledge and understanding of how the sun and the earth interact and trained more than 200 scientists and engineers in a wide range of technical and scientific areas. ISAS developed observing systems for space and atmospheric sciences, ground based optical and radar instruments, and satellite systems, remote sensing technology, and knowledge of STP processes are a vital resource for Canadian Space Science and couples powerfully into high-technology industries.

Ozone Depletion

Atomic oxygen, which is essential to the formation of ozone, is formed in the upper atmosphere from the photo-dissociation of molecular oxygen and then transported downward where it is eventually converted to ozone. Control over the quantity of ozone in the atmosphere occurs in both the region of maximum concentration where it is attacked by chemicals resulting from human activity and in the high atmosphere (>100 km) far removed from the biological shield. It is the significant reduction in the ozone column that occurs in late winter (related to sudden stratospheric warmings) and in early spring that has provided direct evidence for the impact of human activities on the atmosphere. However, the full details of the processes for ozone-loss and those which control global warming are still not adequately understood.

Infra Red Aeronomy and Atmospheric Remote Sensing

One way to improve our measurement database and understanding of those processes responsible for ozone deletion and global change is through the development of new and improved satellite-borne remote sensing instrumentation. The OSIRIS instrument onboard the Odin spacecraft measures vertical profiles of spectrally resolved, limb scattered sunlight from the upper troposphere into the lower mesosphere. OSIRIS has been in standard operation since November 2001 and routinely produces height profiles of O3, NO2 and stratospheric aerosols.  These products have been used to investigate the effects of volcanic eruptions on climate, the long-term trends in changes in the ozone layer, and the physics and chemistry of the mesosphere. The OSIRIS instrument concept (and the related atmospheric science) was developed at ISAS under the leadership of Ted Llewellyn.