1Laboratoire de Météorologie Dynamique (UMR 8539), ENS – CNRS, Paris, France
2Laboratoire 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
Received: 20 Jan 2009 – Published in Atmos. Chem. Phys. Discuss.: 01 Apr 2009
Abstract. 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.
Revised: 01 Mar 2010 – Accepted: 05 Mar 2010 – Published: 01 Apr 2010
Pisso, I., Marécal, V., Legras, B., and Berthet, G.: Sensitivity of ensemble Lagrangian reconstructions to assimilated wind time step resolution, Atmos. Chem. Phys., 10, 3155-3162, doi:10.5194/acp-10-3155-2010, 2010.