Mesoscale Meteorological Simulations In Paris: Comparisons With Observations During The Experiment Eclap

Abstract

This paper analyses the meteorological numerical simulation in Paris during two days (March 10 and 13, 1995) observed during ECLAP (Etude de la Couche Limite en Agglomeration Parisienne– the boundary-layer study of the Paris area), a recent measurement campaign over the Paris area, in which both in-situ and remote-sensing devices at urban and rural locations have been deployed in addition to the operational meteorological network. The chosen days are well documented and correspond to different meteorological situations leading to pollution events (regarding wind direction, cloud cover, surface and synoptic inversion strength).Comparisons of three-dimensional mesoscale model results with the ECLAP observation data are presented, focusing on the temperature field and turbulent fluxes along with the urban heat island and the evolution of the mixing height. It is shown that the model correctly reproduces the main characteristics of the temperature field, its diurnal evolution (near the ground and higher up) especially the gradient between Paris and the surrounding countryside. The mixing-height evolutions are in a good agreement with the observations and the model is also able to reproduce the turbulent features of the atmosphere. The small difference observed between the urban and rural mixing-height evolution is also well reproduced.