Surface energy balance and turbulence network during the Convective and Orographically-induced Precipitation Study (COPS)

Experimental data of the energy balance and the turbulence network installed during the Convective and Orographically-induced Precipitation Study (COPS) field campaign of 2007 are presented in this study. The network aims at providing continuous surface flux and other surface micrometeorological data of the required high accuracy and quality for further fundamental research. An overview of the turbulence data processing and data quality control, including footprint analysis and a check for internal boundary layers, is given. The consistently applied approach allows for a high comparability of the turbulent flux data of sensible and latent heat. The reaction of surface fluxes during the observed frontal passage during the Intensive Observation Period (IOP) 9c (20 July 2007) is presented. As surface fluxes were measured over different land-use types and at different locations within the COPS area, the effect of land use and orography on turbulent fluxes is discussed with the help of IOP 8b (15 July 2007). The flux differences between individual sites due to varying surface characteristics are often larger than the flux differences with changing altitude. The oasis effect observed for the highly evapotranspirating maize fields is found to increase the residuum of the surface energy balance. At all sites and during both IOPs the occurrence of near-ground free convection conditions (FCCs) is investigated. During the oasis effect, FCCs do not occur.