COMPARISON OF SURFACE METEOROLOGICAL MEASUREMENTS IN TRACT-DATABASE-4

The observational systems utilised during the TRACT experimental campa ign (September 1992) can roughly be divided into: existing climate sta tions and towers: background chemical monitoring stations; aerological measurements; instrumented aircraft; and special micrometeorological stations operated only during the experimental period. Database 4, whi ch contains the latter surface measurements, includes station descript ions and data from 21 sites operated by nine different groups during t he campaign period. These data will be described briefly. There are a number of advantages in using a relational database for analysis of th is data. Without creating an unnecessarily large database which is awk ward to view and slow to process, specific measurements can be selecte d easily since data from each site have been standardized using a comm on time index. This allows comparison of the same or different variabl es from one or more sites for investigating data quality or the effect s of site location. Data can readily be combined into hourly or daily averages or time series for comparison with other data sets (e.g. mode l or aircraft data). Spatial analysis is also straightforward, althoug h the clustering of the sites in the centre of the investigation area means that care must be taken. Some preliminary comparisons are made h ere in order to demonstrate the availability and reliability of the da ta.