Environment and Climate Change Canada (ECCC) operates aerological observing stations throughout Canada. These stations complete soundings of the upper atmosphere twice daily for each day of the year. The observations are taken by releasing a gas-filled balloon with an attached instrument which is tracked via one of a variety of electronic navigational methods. This attached instrument transmits meteorological data to the Canadian Meteorological Center relating to temperature, humidity, wind shear and the height of standard atmospheric pressure levels for including in atmospheric models used in forecasting and global weather monitoring.
These soundings are conducted using the Vaisala AUTOSONDE AS41 which provides full automation of the upper air observations from prelaunch, radiosonde preparation, balloon filling, radiosonde launching to data collection, processing and meteorological message generation.