Investigation of vertical eddy fluxes under stable conditions in the surface boundary layer

Dobrovolschi, Dan ; Steeneveld, Gert-Jan ; Paci, Alexandre ; Eiff, Olivier ; Lacaze, Laurent

Année de publication
2010

Understanding and prediction of atmospheric stably stratified boundary layers (SBL) is a longstanding challenge in the field of meteorology (Louis et al., 1981; Holtslag and Nieuwstadt, 1986). In spite of previous SBL studies, either from field experiments (e.g. CASES-99, SHEBA, Cabauw tower, SABLES) or by LES numerical simulations, a need exists for improving the parameterization of turbulent transport of heat, momentum and scalars in the SBL (Cuxart et al., 2006; Steeneveld et al. 2006). This will improve the skill of models for weather forecasting; climate and air quality, in particular for winter and nocturnal conditions.
As an alternative laboratory experiments can provide an extensive dataset with very well-controled parameters such as wind and density vertical profile. Despite a few wind-tunnel experiments have been carried out on SBL, none have been performed with a stratified water flume although this equipment is excellent to investigate the SBL.<br>The current work extends these earlier approaches by parameterization development from laboratory experiments at the CNRM-GAME Toulouse stratified water flume, and compares with field studies and LES. This unique facility is indeed very pertinent for such a study, in particular due to its ability to generate density stratified flow at high Reynolds numbers with low confinement effect.<br>Preliminary tests were performed to ensure that a turbulent, well-developed boundary layer close to a statistical equilibrium can be physically simulated. Our main objectives now are to measure vertical turbulent fluxes of momentum and density, under different conditions of stability and mean flow velocity.

Texte intégral

puce  Accès à la notice sur le site du portail documentaire de Météo-France

  Liste complète des notices publiques