ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-3155-2010 Sensitivity of ensemble Lagrangian reconstructions to assimilated wind time step resolution Pisso I. 1 3 Marécal V. 2 Legras B. 1 Berthet G. 2 Laboratoire de Météorologie Dynamique (UMR 8539), ENS – CNRS, Paris, France Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (UMR 6115), Université d'Orléans – CNRS, Orléans, France now at: Research Institute for Global Change, JAMSTEC, Yokohama, Japan 01 04 2010 10 7 3155 3162 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/10/3155/2010/acp-10-3155-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/3155/2010/acp-10-3155-2010.pdf

We study the impact of temporal and spatial resolution and changes in modelled meteorological winds in the context of diffusive ensemble Lagrangian reconstructions. In situ tracer measurements are modelled based on coarse resolution global 3-D tracer distributions from a chemistry-transport model and on different time series of meteorological wind fields including a special set of 1-hourly analysed winds which is compared with 3 and 6-hourly operational analysed winds and with 3-hourly ERA-interim reanalysis. Increasing the time resolution of the advecting winds from three to one hour using the operational winds provides an improvement on diffusive reconstructions in the period studied but smaller than that obtained from six to three hours. The positive impact of using 1-hourly winds is similar to that obtained using ERA-Interim 3-hourly winds instead of the 3-hourly ECMWF operational analysis for the same period. This study sets out a technique to quantify differences in time series of meteorological wind fields here applied to assess the optimal space and time resolutions for ensemble Lagrangian reconstructions in the lower stratosphere.

 References Berthet, G., Huret, N., Lefèvre, F., Moreau, G., Robert, C., Chartier, M., Catoire, V., Barret, B., Pisso, I., and Pomathiod, L.: On the ability of chemical transport models to simulate the vertical structure of the N<sub>2</sub>O, NO<sub>2</sub> and HNO<sub>3</sub> species in the mid-latitude stratosphere, Atmos. Chem. Phys., 6, 1599–1609, 2006. Bregman, B., Meijer, E., and Scheele, R.: Key aspects of stratospheric tracer modeling using assimilated winds, Atmos. Chem. Phys., 6, 4529–4543, 2006. Demazure, M.: Bifurcations and Catastrophes, Geometry of Solutions to Nonlinear Problems, Universitext, Springer, Berlin, 268~pp., 2000. Hansford, G M., Freshwater, R A., Bosch, R A.,~Anthony Cox, R., Jones, R L., Pratt, K F E., and Williams, D E.: A low cost instrument based on a solid state sensor for balloon-borne atmospheric $O_3$ profile sounding, J. Environ. Monitor., 7, 158–162, 2005. Lefèvre, F.,~Figarol, F.,~Carslaw, K., and~Peter, T.: The 1997 arctic ozone depletion quantified from three-dimensional model simulations, Geophys. Res. Lett., 25, 2425–2428, 1998. Legras, B., Joseph, B., and Lefèvre, F.: Vertical diffusivity in the lower stratosphere from Lagrangian back-trajectory reconstructions of ozone profiles, J. Geophys. Res., 108(D18), 4562, doi:10.1029/2002JD003045, 2003. Legras, B., Pisso, I., Berthet, G., and Lefèvre, F.: Variability of the Lagrangian turbulent diffusion in the lower stratosphere, Atmos. Chem. Phys., 5, 1605–1622, 2005. Norton, W A.: Breaking rossby waves in a model stratosphere diagnosed by a vortex-following coordinate system and a technique for advecting material contours, J. Atmos. Sci., 51, 654–673, 1994. Newell, R E., Thouret, V., Cho, J Y N., Stoller, P., Marenco, A., and Smit, H. G.: Ubiquity of quasi-horizontal layers in the troposphere, Nature, 398, 316–319, 1999. Pisso, I. and Legras, B.: Turbulent vertical diffusivity in the sub-tropical stratosphere, Atmos. Chem. Phys., 8, 697–707, 2008. Pisso, I., Real, E., Law, K. S., Legras, B., Bousserez, N., Attié, J. L., and Schlager, H.: Estimation of mixing in the troposphere from Lagrangian trace gas reconstructions during long-range pollut ion plume transport, J. Geophys. Res., 114, D19301, doi:10.1029/2008JD011289. Pommereau, J.-P., Garnier, A., Held, G., Gomes, A.-M., Goutail, F., Durry, G., Borchi, F., Hauchecorne, A., Montoux, N., Cocquerez, P., Letrenne, G., Vial, F., Hertzog, A., Legras, B., Pisso, I., Pyle, J. A., Harris, N. R. P., Jones, R. L., Robinson, A., Hansford, G., Eden, L., Gardiner, T., Swann, N., Knudsen, B., Larsen, N., Nielsen, J., Christensen, T., Cairo, F., Pirre, M., Marécal, V., Huret, N., Riviére, E., Coe, H., Grosvenor, D., Edvarsen, K., Di Donfrancesco, G., Ricaud, P., Berthelier, J.-J., Godefroy, M., Seran, E., Longo, K., and Freitas, S.: An overview of the HIBISCUS campaign, Atmos. Chem. Phys. Discuss., 7, 2389–2475, 2007. Simmons, A., Uppala, S., Dee, D., and Kobayashi, S.: ERA-Interim: New ECMWF reanalysis products from 1989 onwards, Newsletter 110, ECMWF, 29–35, 2007. Stohl, A., Cooper, O R. and James, P.: A cautionary note on the use of meteorological analysis fields for quantifying atmospheric mixing, J. Atmos. Sci., 61, 1446–1453, 2004. Stohl, A., Forster, C., Frank, A., Seibert, P., and Wotawa, G.: Technical note: The Lagrangian particle dispersion model FLEXPART version 6.2, Atmos. Chem. Phys., 5, 2461–2474, 2005. Sutton, R.: Lagrangian flow in the middle atmosphere, Q. J. Roy. Meteorol. Soc., 120B(519), 1299–1320, 1994. Thompson, A., J. C. Witte, R. D. McPeters, S. J. Oltmans, F. J. Schmidlin, J. A. Logan, M. Fujiwara, V. W. J. H. Kirchhoff, F. Posny, G. J. R. Coetzee, B. Hoegger, S. Kawakami, T. Ogawa, B. J. Johnson, H. Vomel, and G. Labow: Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998–2000 tropical ozone climatology, 1, Comparison with Total Ozone Mapping Spectrometer (TOMS) and ground-based measurements, J. Geophys. Res., 108(D2), 8238, doi:10.1029/2001JD000967, 2003. Wilson, J. D. and Sawford, B. L.: Review of Lagrangian stochastic models for trajectories in the turbulent atmosphere, Bound.-Lay. Meteorol., 78, 191–210, 1996.