Skip to main content

The Science Case

The global atmosphere is changing throughout its entire depth from the surface to the fringes of space due to anthropogenic emissions and natural sources of greenhouse gases, pollutants, aerosol precursors, and the recovery from ozone-depleting substances


Changes in atmospheric composition are closely coupled with changes in circulation and together affect surface climate, weather and air quality.


To achieve a step change in our understanding of the coupling of atmospheric circulation, composition and regional climate change, CAIRT addresses the following specific science objectives:

  • Quantify the middle-atmosphere circulation from the upper troposphere to the lower thermosphere by providing accurate and high resolution observations of age-of-air, temperature and long-lived trace gases,
  • Quantify the atmospheric gravity wave momentum flux and wave driving through temperature observations at unprecedented scales,
  • Attribute changes in stratospheric ozone due to circulation and chemistry by providing observations of the relevant chemical species,
  • Quantify the flux of reactive nitrogen species from the upper atmosphere into the stratosphere to improve our understanding how transient solar events and space weather affect natural climate variability,
  • Quantify the upper troposphere and lower stratosphere (UTLS) aerosol composition and precursor gases,
  • Quantify UTLS variability, stratosphere-troposphere exchange and its impact on tropospheric composition and air quality.