PDF version of COSPAR - Space Science Research in Canada Report

objective of the OSIRIS project, but the quality of the data turned out to be betterthan anyone anticipated.She noted that researchers have paid much attention to what is happening in thestratosphere, the atmospheric region below the mesosphere, but they are nowrealizing that “to fully understand the processes there, we need to look further upand understand the water content.”OSIRIS is also gathering data on polar stratospheric clouds. They are known toaccelerate ozone depletion and play a key role in creating ozone holes over thepoles. Ironically, the ideal conditions for their formation – extremely coldtemperatures in the stratosphere – occur because the greenhouse gases thatcause global warming trap heat closer to the Earth’s surface, resulting instratospheric cooling.Finally, OSIRIS is being used to detect another type of high-altitude clouds: ultrathinor sub-visual cirrus clouds, which are also believed to play an importantclimatic role. This work is being done by graduate student Adam Bourassa, whohas just completed his PhD. He has also been using OSIRIS to study sulphateaerosols, industrial pollutants in the atmosphere that influence cloud formation.Melo said OSIRIS is producing unique three-dimensional maps of aerosolpollution. Measurements of how these pollutants are transported around theglobe can be used as an indirect measure of the movement of air parcels in theupper atmosphere. “We don’t have any direct measurements of the winds in thestratosphere,” she said. “This adds one extra component to the collection ofinformation.”The loss of several other satellites that were studying ozone and otheratmospheric constituents has put OSIRIS in the important but unexpectedposition of bridging a gap in data collection. It is difficult to meld data fromdifferent satellites and instruments but fortunately, there is an overlap of aboutthree and a half years between the OSIRIS data and those from other satellites,which should enable scientists to correlate the information and producecontinuous trend information.62