Evaluation of ECMWF ERA-40 temperature and wind in the lower tropical stratosphere since 1988 from past long-duration balloon measurements T. Christensen, B. M. Knudsen, J.-P. Pommereau, G. Letrenne, A. Hertzog, F. Vial, J. Ovarlez, and M. Piot Danish Meteorological Institute, Copenhagen, Denmark Service d’Aéronomie, IPSL/CNRS, Verrières-Le-Buisson, France Centre National d’Études Spatiales, To...