1. University of Liège (ULg) activities based on long-term FTIR observations performed at the Jungfraujoch station Jungfraujoch, 46.5°N, 8.0°E, 3580m alt. HYMN Kick-Off Meeting KNMI, 10-11 October, 2006

2. People involved and related tasks P. Demoulin, P. Duchatelet, C. Servais and E. Mahieu With support of J. Bosseloirs, O. Flock, V. Van de Weerdt and D. Zander Instrumental development and automatisation for remote control operation (hardware and software) Routine operation of the instruments on site Data treatment and analysis of the observations Archiving of the resulting time series and valorisation of the results In close collaboration with the team of M. De Mazière (BIRA-IASB)

3. Financial support essentially through Participation to recent EC-projects SOGE, UFTIR and EVERGREEN Involvement in EC-FP6: HYMN and IP-GEOMON Participation to several national and regional projects

4. Instrumentation and observational database ULg has started IR observations at the Jungfraujoch station in the early fifties, with a grating spectrometer; these pioneering measurements have been digitised and valorised Regular recording of high-resolution IR solar spectra performed since the mid-eighties, with a homemade interferometer in both the MCT and INSB spectral domains Given the commitments toward the NDSC network (now NDACC), the ULg observational capacities have been expanded in 1990 with a second instrument (Bruker 120HR), providing higher performances

5. Current status of the Jungfraujoch databases More than 37000 high-resolution IR solar spectra have been recorded since 1984, with the two FTS instruments Density of observations has significantly increased after 1990 [123±13] days of observations available per year, on average over 1996-2005 (i.e. 1 day over 3) About two-dozen species routinely retrieved Time series archived at NDACC ( ftp://ftp.cpc.ncep.noaa.gov/ndacc/), NILU-NADIR (UFTIR and ENVISAT CAL/VAL) ftp://ftp.cpc.ncep.noaa.gov/ndacc/

6. Molecules currently studied in FTIR solar spectra recorded at the Jungfraujoch (*) Reference gas: N 2 Minor constituents: CO 2, N 2 O, CH 4, CO, O 3 Trace constituents: Halogenated species: CCl 2 F 2, CHClF 2, CCl 3 F, CCl 4, SF 6 HCl, ClONO 2, HF, COF 2 Nitrogenated species: NO, NO 2, HNO 3 Others: C 2 H 6, C 2 H 2, HCN, OCS, H 2 CO 2, H 2 CO, [CH 3 Cl, HNO 4, H 2 O, C 2 H 4...] (*) Total (and also often partial) column abundances can be retrieved routinely from Jungfraujoch individual observations. Species typed in italic are primarily present in the stratosphere, while the others are tropospheric source gases. Species between brackets are under evaluation.

7. Monthly mean time series

8. Annual changes over specified periods, in molec./cm 2 and in (%) Species Fit. order1987-19881991-19921995-19961999-20002003-2004 CO 2 12.24xE19 (0.45) 2.24xE19 (0.44) 2.24xE19 (0.43) 2.24xE19 (0.42) 2.24xE19 (0.42) CH 4 21.56xE17 (0.72) 1.14xE17 (0.51) 0.71xE17 (0.31) 0.28xE17 (0.12) -0.15xE17 (-0.06) N2ON2O 11.06xE16 (0.27) 1.06xE16 (0.26) 1.06xE16 (0.26) SF 6 13.36xE12 (12.2) 3.36xE12 (8.20) 3.36xE12 (6.17) 3.36xE12 (4.95) 3.35xE12 (4.13) CO 2-7.88xE15 (-0.63) -5.59xE15 (-0.46) -3.30xE15 (-0.27) -1.02xE15 (-0.09) 1.27xE15 (0.11) C2H6C2H6 2-4.56xE14 (-3.08) -3.41xE14 (-2.58) -2.26xE14 (-1.87) -1.10xE14 (-0.97) 0.05xE14 (0.04) C2H2C2H2 1-4.48xE13 (-2.19) -4.48xE13 (-2.40) -4.48xE13 (-2.65) -4.48xE13 (-2.96) -4.48xE13 (-3.36) HCN 18.55xE11 (0.03) 8.55xE11 (0.03) 8.55xE11 (0.03) 8.55xE11 (0.03) 8.55xE11 (0.03) CCl 2 F 2 72.11xE14 (3.71) 1.38xE14 (2.17) 0.77xE14 (1.13) 0.27xE14 (0.39) -0.11xE14 (-0.16) CCl 3 F 1----1.85xE13 (-0.58) -1.85xE13 (-0.59) CHClF 2 57.93xE13 (7.54) 8.34xE13 (6.05) 8.35xE13 (4.88) 7.98xE13 (3.91) 7.21E+13 (3.07) OCS NPLS (20%)-9.48xE13 (-1.36) -5.45xE13 (-0.82) -3.00xE13 (-0.46) -4.37xE13 (-0.67) +6.86xE13 (1.05) CCl 4 2 14.04xE12 (0.27) -4.08xE12 (-0.28) -1.22xE13 (-0.85) -2.03xE13 (-1.48) -2.62xE13 (-2.06)

9. Use & valorisation of the data Monitoring of the atmosphere (stratosphere and troposphere: detection of short- and long-term trends, emission “anomalies”…) Calibration/Validation of space-based sensors (e.g. MIPAS, SCIAMACHY, ACE-FTS…) Use for evaluation of model performances Support to policy makers (e.g. through involvement in international, national and regional assessments) …

10. HYMN-related activities, scientific products & expected results Description of existing HYMN-related products: see overview presentation Continue to perform solar absorption measurements at the Jungfraujoch station [2006-2008] Contribute to the optimization of the retrieval strategy for methane Contribute to the evaluation of the error budgets for methane and nitrous oxide vertical profile retrievals Generate the Jungfraujoch time series, according to the settled approaches for comparison with models and satellite validation