PYREX: A Summary of Findings

Abstract

About six years ago, the planned field experiment Pyrenean Experiment (PYREX) was presented in the Bulletin. After a successful field phase in October and November 1990, and much work to prepare a consistent database, interpret the measurements, and compare model results with observations, it is possible to present today a summary of scientific results. New insight has been obtained in the areas of mountain drag measurement and interpretation, humidity measurement, boundary layer measurement by lidar, the ability of mesoscale models to represent orographic flows, the roughness length of mountains, and parameterization of subgrid-scale gravity waves. The present paper summarizes these results and may be understood as an introduction to this unique dataset on orographic flows. The authors believe that much interesting research can still be achieved with the PYREX data, which are accessible to any interested scientist.