In the global mean approximately half of the Earth's outgoing longwave energy to space is from wavelengths greater than 15 microns, within the so-called far-infrared (FIR). Despite its major contribution to the Earth’s radiation budget, the region is still under-unexplored. Theoretical studies, and those observations which do exist, show that FIR emission is highly sensitive to upper tropospheric/lower stratospheric water vapour, controls mid-upper tropospheric cooling rates and hence plays a key role in water vapour and lapse rate feedback processes. Similarly, studies indicate that an improved characterisation of ice, and potentially mixed-phase, cloud can be leveraged from measurements of the outgoing top of atmosphere FIR spectrum. Recent work also implies that FIR surface emission may have an important part to play in determining Arctic surface temperatures, sea ice extent and the rate of change of both quantities. Recognising its scientific importance, ESA and NASA have independently selected the Far infrared Outgoing Radiation Understanding and Monitoring (FORUM) mission and the Polar Radiant Energy in the Far Infrared Experiment (PREFIRE) as candidate satellite missions focused on measuring the Earth’s outgoing FIR emission from space.

In this session we encourage submissions from scientists working in all areas of FIR science, including instrument development, measurement exploitation, spectroscopy, etc. We particularly welcome contributions which consider how measurements of the FIR spectrum may benefit weather and climate prediction.