1. 1 Water vapour continuum in windows: Processing the recent MSF RAL measurements Igor Ptashnik Dept. of Meteorology, University of Reading 10 February 2011 Cambridge

2. 2 Processing MSF RAL pure H 2 O measurements Retrieved experimental self-continuum in windows is an order of magnitude stronger than MTCKD in model. For 2500 cm -1 and 4600 cm -1 windows the disagreement increases with temperature, reaching a factor 25 at 470 K. Ptashnik, McPheat, Shine, Smith, Williams, submitted to J. Geophys. Res.

3. 3 Temperature dependence. Simple analysis.

4. 4

5. 5 Saturated P H2O (mb) T (K)P H2O (mb) 3530010(F), 20(F) 41635010(F), 50(F), 300 F 100037550(F), 400, 600 F,750 2500400 600 F,1000, 1500 F,2000 5700430 600 F,1000, 1500,2000, 3000, 4000 14000470 1000,2000, 3000, 4000, 5000 Resolution (cm -1 ): N of scans: 0.050.1 0.2 : 0.3 1000 500 MSF RAL measurements (R. McPheat, K. Smith, G. Willaims) Foreign H2O measurements (foreign-continuum) 1) empty cell 2) Air (5 atm) - background 3) H 2 O + Air (total 5 atm) - sample 4) Air (5 atm) - background 5) empty cell

6. 6 MSF RAL measurements: H 2 O - Air Foreign H2O-Air continuum Is derived as: (RAL – UCL lines ) – RAL self-continuum CIA N 2 -N 2 and O 2 -O 2 contribution is subtracted by using Air as a background.

7. 7 Foreign continuum: H 2 O – Air Foreign H2O-Air continuum in near-IR windows is also an order of magnitude stronger than in MT_CKD-2.5 model! 350 K 372 K 400 K Air

8. 8 Water vapour self-continuum and water dimers: 1. Analysisof recent work IV Ptashnik, KP Shine, AA Vigasin, JQSRT, in press

9. 9 Water vapour self-continuum and water dimers: 2...... in preparation...