Our changing atmosphere: evidence based on long-term infrared solar observations at the Jungfraujoch since 1950.

The Institute of Astrophysics of the University of Liège has been present at the High Altitude Research Station Jungfraujoch, Switzerland, since the late 1940s, to perform spectrometric solar observations under dry and weakly polluted high-mountain conditions. Several solar atlases of photometric quality, extending altogether from the near-ultra-violet to the middle-infrared, were produced between 1956 and 1994, first with grating spectrometers then with Fourier transform instruments. During the early 1970s, scientific concerns emerged about atmospheric composition changes likely to set in as a consequence of the growing usage of nitrogen-containing agricultural fertilisers and the industrial production of chlorine-bearing compounds such as the chlorofluorocarbons and hydro-chlorofluorocarbons. Resulting releases to the atmosphere with ensuing photolysis in the stratosphere and catalytic depletion of the protective ozone layer prompted a worldwide consortium of chemical manufacturing companies to solicit the Liège group to help in clarifying these concerns by undertaking specific observations with its existing Jungfraujoch instrumentation. The following pages evoke the main steps that led from quasi full sun-oriented studies to priority investigations of the Earth's atmosphere, in support of both the Montreal and the Kyoto Protocols.

Monitoring of the atmospheric burdens of CH4, N 2O, CO, CHCIF 2 and CF 2Cl 2 above Central Europe during the last decade.

Based on high spectral resolution infrared solar observations made at the International Scientific Station of the Jungfraujoch, Switzerland, total vertical column abundances of 18 atmospheric gases have been monitored routinely since 1984. The observed temporal evolutions in the columns of CH4, N2O, CO, CHClF2 (HCFC-22) and CF2Cl2 (CFC-12) are reported here as typical examples of this monitoring effort which is conducted within the frame of "Global Change" and "Network for the Detection of Stratospheric Change" programs.

[Post-traumatic infections of the frontal sinus]. / Infections post-traumatiques du sinus frontal.

Post-traumatic infectious complications of the frontal sinus occur more frequently after multiple fractures than after isolated fractures. The greatest frequency is found with open traumas of the sinus, due to the presence of foreign bodies and to bone and mucosal destruction. Such infectious complications are curatively treated both medically and surgically, to eliminate the bony and mucosal infection and to restore the normal physiology of the frontal sinus. Stress is laid on the preventive treatment, especially on the quality of the initial surgical treatment, either by restoring the sinus with gauging of the nasal-frontal canals, or by eliminating the sinusal function by a canalization which appears preferable to exclusion by obliteration.