> ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Experimental line list of water vapor absorption lines in the spectral ranges 1850–2280 cm-1 and 2390–4000 cm-1 Joep Loos, Manfred Birk, Georg Wagner German Aerospace Center (DLR) – Remote Sensing Technology Institute

Ground-based remote sensing – H2O spectoscopic database > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Ground-based remote sensing – H2O spectoscopic database Schneider et al. JQSRT 112 (2011) 465-474 Karlsruhe (Germany), ground-based solar occultation measurement Large spectral residuals Erroneous data products (e.g. water vapor concentration profiles) Inaccurate line parameter values and insufficient line profile  Improvement of H2O line parameters in the range 1850 – 4000 cm-1

FT-Transmittance measurements at DLR > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 FT-Transmittance measurements at DLR High-resolution Fourier transform spectrometer Bruker IFS 125HR White-type multireflection cell directly attached to the interferometer Absorption path 14.4-206.4 m Temperature range 198-360 K Continuous flow of sample gas

FT-Transmittance measurements at DLR > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 FT-Transmittance measurements at DLR 0.1 mbar H2O, 0.249 m, 296 K 20.0 mbar H2O, 174.6 m, 296 K H2O, RT H2O/air, RT H2O/Luft, HT/LT pH2O (mbar) 0.1 – 20 0.2 – 7.5 0.01 – 9.0 ptot (mbar) 30 – 1000 90/100 l (m) 0.219 – 174.61 0.249 – 168.21 T (K) 296 213 – 350

Analysis Multispectrum least squares fitting > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Analysis Multispectrum least squares fitting HITRAN12 as starting point qSDHC + Rosenkranz line mixing based on HTP implementation by Tran et al. Retrieval of line positions, intensities and line shape parameters Speed-dependence, Dicke-narrowing and line mixing have to be taken into account

Statistics for fitted line parameters > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Statistics for fitted line parameters HITRAN12 DLR Parameter Isotopolog s S g0,s g2,s d0,s ns dT0,s Ys YsT1 H216O 4016 4002 3323 2678 2574 1884 1276 143 6 1036 1034 739 500 477 253 136 3 622 620 396 241 211 110 48 HDO 1300 1291 841 509 456 204 64 8 6974 6947 5299 3928 3718 2451 1524 154 Parameter Isotopolog g0,a g2,a d0,a nVC,a na dT0,a Ya YaT1 YaT2 H216O 2655 1690 2268 234 2487 2010 345 6 2 481 167 334 3 406 254 4 218 74 132 180 101 HDO 470 88 140 324 155 S 3824 2019 2984 237 3397 2520 355 1850 – 2280 cm-1 and 2390 – 4000 cm-1 S > 1∙10-26 cm molecule-1 ~ 7000 lines > 46000 parameters

Line intensities – Comparison to HITRAN12, GEISA15 and ab initio > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Line intensities – Comparison to HITRAN12, GEISA15 and ab initio HITRAN12 GEISA15 ab initio Ab initio: Birk et al. JQSRT, im Druck (2017), Lodi et al. JCP 128 (2008) 044304, Lodi et al. JCP 135 (2011) 134113.

Line intensities – Comparison to ab initio > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Line intensities – Comparison to ab initio sexp < 1% Good agreement for n2-, n3-lines (better than 1% on average) Large scatter and systematic deviation for n1-lines Ab initio: Birk et al. JQSRT, im Druck (2017), Lodi et al. JCP 128 (2008) 044304, Lodi et al. JCP 135 (2011) 134113.

Air-broadening widths and speed-dependence > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Air-broadening widths and speed-dependence Ratio speed-dependence/air broadening g2,0/g0,a almost constant Air-broadening parameters systematically larger than HITRAN12 values  different line shape model used in analysis

Impact on atmospheric retrievals > ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Impact on atmospheric retrievals Significant improvement of spectral residuals in comparison to the use of HITRAN12

> ISMS 2017 > Joep Loos • P2355: Experimental line list of water vapor > 2017-06-20 Summary Experimental line parameter list in the spectral ranges 1850 – 2280 and 2390 – 4000 cm-1 Multispectrum analysis of pure H2O and H2O/air-mixture transmittance measurements Use of quadratic speed-dependent hard collision model + Rosenkranz line mixing Line intensity range down to 10-26 cm molecule-1 Use of the new line parameters reduces spectral residuals significantly in atmospheric retrievals Line parameters included in HITRAN16 Parameter list available dx.doi.org/10.1016/j.jqsrt.2017.02.013 dx.doi.org/10.1016/j.jqsrt.2017.03.033