Quality Control Techniques Applied to ISFS and ISS Perdigão Field Campaign Data

The Perdigão field campaign was a comprehensive, international project aimed at improving the understanding of atmospheric flow over complex terrain, from mesoscale to microscale. During the project, a lower-atmospheric, reference data set was collected at an unprecedented spacial and temporal resolution in order to characterize the mean and turbulent wind fields across a pair of ridges near Perdigão, Portugal. The project also focused on measuring the mean and turbulent temperature and moisture fields, as well as measuring the surface energy balance.

The Perdigão project included the deployment of the Integrated Surface Flux System (ISFS) and the Integrated Sounding System (ISS) of the National Center for Atmospheric Research Earth Observing Lab (EOL). The ISFS deployment consisted of 48 towers instrumented with 3-D sonic anemometers, temperature/relative humidity (T/RH) sensors, barometers, and radiometers. The primary goal of these sensors was to determine turbulence and thermodynamic fluxes across the ridges and throughout the valley in between. The ISS deployment consisted of three sites, one with a 1290 MHz radar wind profiler and Radio Acoustic Sounding System (RASS), another with a Sodar/RASS, and a final site from which radiosondes were released. Each site also included surface meteorological sensors. The ISS objective was to characterize the in-flow, out-flow, and thermodynamic profiles surrounding the ridges and valley, and to serve as an important validation source for the remote sensing data sets collected.

Presented herein is an overview of the extensive data quality-control (QC) procedures applied to the ISFS and ISS datasets collected during the Perdigão project. The QC process includes merging datasets from various storage devices, rotating and tilt-correcting data from 183 sonic anemometers, and removing anomalous data points from all sensors. Additionally, bias and post-calibration corrections are calculated and applied to the entire array of sonic anemometers, T/RH sensors, barometers, radiometers, soil sensors, and rain gauges. Error statistics are then computed and QC tables are generated for each day of each variable. A similar QC process is performed on data collected by the ISS radar wind profiler and RASS, Sodar/RASS, and surface meteorological sensors. Finally, the data are archived and released to the investigators with appropriate documentation and metadata through EOL’s online database. This database includes dataset versioning, important contacts, and Digital Object Identifier (DOI) citation information to inform data users of future dataset updates and aid in reproducibility of results.