ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-9-9433-2009 H<sub>2</sub><sup>16</sup>O and HDO measurements with IASI/MetOp Herbin H. 1 3 Hurtmans D. 1 Clerbaux C. 1 2 Clarisse L. 1 4 Coheur P.-F. 1 4 Spectroscopie de l'Atmosphère, Service de Chimie Quantique et de Photophysique, Université Libre de Bruxelles, Brussels, Belgium UPMC Univ. Paris 06; Université Versailles St-Quentin; CNRS/INSU, LATMOS-IPSL, Paris, France now at: Laboratoire d'Optique Atmosphérique, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq cedex, France respectively Research Associate and Scientific Research Worker with the F.N.R.S., Belgium 15 12 2009 9 24 9433 9447 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/9/9433/2009/acp-9-9433-2009.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/9/9433/2009/acp-9-9433-2009.pdf

In this paper we analyze distributions of water vapour isotopologues in the troposphere using infrared spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI), which operates onboard the Metop satellite in nadir geometry. The simultaneous uncorrelated retrievals of H<sub>2</sub><sup>16</sup>O and HDO are performed on radiance measurements using a line-by-line radiative transfer model and an inversion procedure based on the Optimal Estimation Method (OEM). The characterizations of the retrieved products in terms of vertical sensitivity and error budgets show that IASI measurements contain up to 6 independent pieces of information on the vertical distribution of H<sub>2</sub><sup>16</sup>O and up to 3.5 for HDO from the surface up to the upper troposphere (0–20 km). Although the purpose of the paper is not validation, a restricted comparison with sonde measurements shows that the retrieved H<sub>2</sub><sup>16</sup>O profiles capture the seasonal/latitudinal variations of the water content, with good accuracy in the lowest layer but with larger uncertainties higher in the free and upper troposphere. Our results then demonstrate the ability of the IASI instrument to monitor atmospheric isotopologic water vapour distributions and to provide information on the partitioning of HDO as compared to H<sub>2</sub><sup>16</sup>O. The derivation of the &delta;<sub><i>D</i></sub> is challenging and associated with large errors in the uncorrelated retrieval approach chosen here. As a result averaging on the vertical to produce a column-averaged &delta;<sub><i>D</i></sub> is required to produce meaningful results for geophysical interpretation. As a case study, we analyse concentration distributions and spatio-temporal variations of H<sub>2</sub><sup>16</sup>O and &delta;<sub><i>D</i></sub> during the October 2007 Krosa super-typhoon over South-East Asia. We show that individual &delta;<sub><i>D</i></sub> have uncertainties of 37&permil; for the vertically averaged values. Using the latter, we suggest that the typhoon produces a so-called amount-effect, where the &delta;<sub><i>D</i></sub> is negatively correlated to the water amounts as a result of intense depletion of the deuterated species.

 References Barret, B., Turquety, S., Hurtmans, D., Clerbaux, C., Hadji-Lazaro, J., Bey, I., Auvray, M., and Coheur, P.-F.: Global carbon monoxide vertical distributions from spaceborne high-resolution FTIR nadir measurements, Atmos. Chem. Phys., 5, 2901–2914, 2005. Beer, R., Glavich, T. A., and Rider, D. M.: Tropospheric emission spectrometer for the Earth Observing System's Aura Satellite, Appl. Optics, 40(15), 2356–2367, 2001. Bowen, G. J. and Revenaugh, J.: Interpolating the isotopologic composition of modern meteoric precipitation, Water Resour. Res., 39(9), 1299, doi:2003WR002086, 2003. Brown, D., Worden, J., and Noone, D.: Comparison of hydrology over convective continental regions using water vapor isotope measurements from space, J. Geophys. Res., 113, D15124, doi:10.1029/2007JD009676, 2008. Ciais, P. and Jouzel, J.: Deuterium and oxygen~18 in precipitation: Isotopologic model, including mixed cloud processes, J. Geophys. Res., 99(D8), 16793, doi:94JD00412, 1994. Clerbaux, C., Hadji-Lazaro, J., Turquety, S., George, M., Coheur, P.-F., Hurtmans, D., Wespes, C., Herbin, H., Blumstein, D., Tournier, B., and Phulpin, T.: The IASI/MetOp mission: first observations and highlight of its potential contribution to the GMES Earth observation component, Space Res. Today, 168, 19–24, 2007. Clerbaux, C., Boynard, A., Clarisse, L., George, M., Hadji-Lazaro, J., Herbin, H., Hurtmans, D., Pommier, M., Razavi, A., Turquety, S., Wespes, C., and Coheur, P.-F.: Monitoring of atmospheric composition using the thermal infrared IASI/MetOp sounder, Atmos. Chem. Phys., 9, 6041–6054, 2009. Coffey, M. T., Hannigan, J. W., and Goldman, A.: Observations of upper tropospheric/lower stratospheric water vapour and its isotopologues, J. Geophys. Res., 111, D14, doi:10.1029/2005JD006093, 2006. Coheur, P.-F., Barret, B., Turquety, S., Hurtmans, D., Hadji-Lazaro, J., and Clerbaux, C.: Retrieval and characterization of ozone vertical profiles from a thermal infrared nadir sounder, J. Geophys. Res., 110, D24, doi:2005JD005845, 2005. Dansgaard, W.: Stable isotopes in precipitation, Tellus, 16(3), 436–468, 1964. Ehhalt, D. H., Rohrer, F., and Fried, A.: Vertical profiles of HDO/H<sub>2</sub>O in the troposphere, J. Geophys. Res., 110, D13, doi:10.1029/2004JD005569, 2005. Franz, P. and Röckmann, T.: High-precision isotope measurements of H$_2^16$O, H$_2^17$O, H$_2^18$O, and the $\Delta^17$O-anomaly of water vapor in the southern lowermost stratosphere, Atmos. Chem. Phys., 5, 2949–2959, 2005. Gaffen, D.: Temporal inhomogeneities in radiosonde temperature records, J. Geophys. Res., 99D2, 3667–3676, 1994. Galewsky, J., Strong, M., and Sharp, Z. D.: Measurements of water vapor D/H ratios from Mauna Kea, Hawaii, and implications for subtropical humidity dynamics, Geophys. Res. Lett., 34, L22808, doi:10.1029/2007GL031330, 2007. Gedzelman, S. D. and Lawrence, J. R.: The isotopic composition of cyclonic precipitation, J. Appl. Meteorol., 21, 1385–1404, 1982. Gedzelman, S. D., Hindman, E., Zhang, X., Lawrence, J., Gamache, J., Black, M., Black, R., Dunion, J., and Willoughby, H.: Probing Hurricanes with stable isotopologues of rain and water vapor, Mon. Weather Rev., 131, 1112–1127, 2003. Gettelman, A. and Webster, C. R.: Simulations of water isotopologue abundances in the upper troposphere and lower stratosphere and implications for stratosphere troposphere exchange, J. Geophys. Res., 110, D17, doi:10.1029/2004JD004812, 2005. Hanisco, T. F., Moyer, E. J., Weinstock, E. M., St Clair, J. M., Sayres, D. S., Smith, J. B., Lockwood, R., and Anderson, J. G.: Observations of deep convective influence on stratospheric water vapor and its isotopic composition, Geophys. Res. Lett., 34, L048141–L048145, 2007. Hartmann, D. L.: Climate Change: Tropical Surprises, Science, 295, 811–812, 2002. Herbin, H., Hurtmans, D., Turquety, S., Wespes, C., Barret, B., Hadji-Lazaro, J., Clerbaux, C., and Coheur, P.-F.: Global distributions of water vapour isotopologues retrieved from IMG/ADEOS data, Atmos. Chem. Phys., 7, 3957–3968, 2007. Johnson, D. J., Jucks, K. W., Traub, W. A., and Chance, K. V.: Isotopic composition of stratospheric water vapor: Implications for transport, J. Geophys. Res., 106(D11), 12219–12226, 2001. Kuang, Z. M., Toon, G. C., Wennberg, P. O., and Yung, Y. L.: Measured HDO/H<sub>2</sub>O ratios across the tropical tropopause, Geophys. Res. Lett., 30(6), 1372, doi:2003GL017023, 2003. Lawrence, J. R. and Gedzelman, S. D.: Low stable isotope ratios of tropical cyclone rains, Geophys. Res. Lett., 23(4), 527–530, 1996. Lawrence, J. R., Gedzelman, S. D., Zhang, X., and Arnold, R.: Stable isotope ratios of rain and vapor in 1995 hurricanes, J. Geophys. Res., 103(9), 11381–11400, 1998. Lawrence, J. R., Gedzelman, S. D., Gamache, J., and Black, M.: Stable isotopologue ratios: Hurricane Olivia, J. Atmos. Chem., 41, 67–82, 2002. Lawrence, J. R., and Gedzelman, S. D.: Tropical ice core isotopes: Do they reflect changes in storm activity, Geophys. Res. Lett., 30(2), doi:10.1029/2002GL015906, 2003. McCarthy, M. C., Boering, K. A., Rahn, T., Eiler, J. M., Rice, A. L., Tyler, S. C., Schauffler, S., Atlas, E., and Johnson, D. G.: The hydrogen isotopologic composition of water vapour entering the stratosphere inferred from high-precision measurements of $\delta_D$-CH<sub>4</sub> and $\delta_D$-H<sub>2</sub>, J. Geophys. Res., 109, D07, doi:10.1029/2003JD004003, 2004. Moyer, E. J., Irion, R. W., Yung, Y. L., and Gunson, M. R.: ATMOS stratospheric deuterated water vapour and implications for troposphere-stratosphere transport, Geophys. Res. Lett., 23(17), 2385, doi:96GL01489, 1996. Razavi, A., Clerbaux, C., Wespes, C., Clarisse, L., Hurtmans, D., Payan, S., Camy-Peyret, C., and Coheur, P. F.: Characterization of methane retrievals from the IASI space-borne sounder, Atmos. Chem. Phys., 9, 7889–7899, 2009. Rodgers, C. D.: Inverse Methods for Atmospheric Sounding: Theory and Practice, World Sci., Hackensack, N. J., 2000. Rosenlof, K. H., Oltmans, S. J., Kley, D., Russell, J. M., Chiou, E.-W., Chu, W. P., Johnson, D. G., Kelly, K. K., Michelsen, H. A., Nedoluha, G. E., Remsberg, E. E., Toon, G. C., McCormick, M. P.: Stratospheric water vapour increases over the past half-century, Geophys. Res. Lett., 28(6), 1195, doi:2000GL012502, 2001. Rosenlof, K. H.: How water enters the stratosphere, Science, 302, 1691–1692, 2003. Rothman, L. S., Jacquemart, D., Barbe, A., et al.: The HITRAN~2004 molecular spectroscopic database, J. Quant. Spectrosc. Ra., 96, 139–204, 2005. Schlüssel, P., Hultberg, T. H., Phillips, P. L., August, T., and Calbet, X.: The operational IASI Level~2 processor, Adv. Space Res., 36, 982–988, 2005. Schmidt, G. A., Hoffmann, G., Shindell, D. T., and Hu, Y.: Modelling atmospheric stable water isotopologues and the potential for constraining cloud processes and stratosphere-troposphere water exchange, J. Geophys. Res., 110, D21, doi:2005JD005790, 2005. Schneider, E. K., Kirtman, B. P., and Lindzen, R. S.: Tropospheric Water Vapour and Climate Sensitivity, J. Atmos. Sci., 56, 1649–1658, 1999. Schneider, M., Hase, F., and Blumenstock, T.: Ground-based remote sensing of HDO/H<sub>2</sub>O ratio profiles: introduction and validation of an innovative retrieval approach, Atmos. Chem. Phys., 6, 4705–4722, 2006. Smith, R. B.: Deuterium in North Atlantic storm tops, J. Atmos. Sci., 49, 2041–2057, 1992. Steinwagner, J., Milz, M., von Clarmann, T., Glatthor, N., Grabowski, U., Höpfner, M., Stiller, G. P., and Röckmann, T.: HDO measurements with MIPAS, Atmos. Chem. Phys., 7, 2601–2615, 2007. Strong, M., Scharp, Z. D., and Gutzler, D. S.: Diagnosing moisture transport using D/H ratios of water vapor, Geophys. Res. Lett., 34, L03404, doi:2006GL028307, 2007. University of Wyoming' department of atmospheric sciences radiosondes data base: http://weather.uwyo.edu/upperair/sounding.html. Webster, C. R. and Heymsfield, A. J.: Water isotopologue ratios D/H, $^18$O/$^16$O, $^17$O/$^16$O in and out of clouds map dehydration pathways, Science, 302, 1742–1745, 2003. Worden, J., Bowman, K., Noone, D., et al.:: Tropospheric Emission Spectrometer observations of the tropospheric HDO/H<sub>2</sub>O ratio: Estimation approach and characterization, J. Geophys. Res., 111, D16, doi:10.1029/2005JD006606, 2006. Worden, J., Noone, D., Bowman, K., et al.: Importance of rain evaporation and terrestrial sources in the tropical water cycle, Nature, 445, 528–553, 2007. Zahn, A., Franz, P., Bechtel, C., Grooß, J.-U., and Röckmann, T.: Modelling the budget of middle atmospheric water vapour isotopes, Atmos. Chem. Phys., 6, 2073–2090, 2006. Zhang, X., Tian, L., and Liu, J.: Fractionation mechanism of stable isotope in evaporating water body, J. Geophys. Res., 15, 375–384, 2005.