Development and quality control of the FASTEX Data Archive

The Fronts and Atlantic Storm Track EXperiment (FASTEX) was conducted over the North Atlantic during January and February 1997. The FASTEX Data Archiv e is a combination of the datasets collected as a part of the two-month int ensive field season and many supplementary datasets and products retrieved from the participating nations and cooperating agencies. The archive is com posed of the FASTEX Central Archive (FCA) and a group of specialized databa ses. The technical design of the FCA allowed rigorous management of the data and made the checking of the data easy to accomplish. This rigorous management was accomplished using customized quality control evaluation techniques as determined by the individual datasets received at the FCA. An important aspect of FASTEX data archival activities was the collection, processing and production of a high-resolution rawinsonde and dropsonde dat aset. These data are of importance to model-verification studies and mesosc ale analysis in FASTEX. Data from rawinsondes released from land sites and operational and research ships as well as dropsondes from five aircraft are included. The activities of two groups involved in the preparation of this dataset are described. The humidity measurements by the rawinsondes and dropsondes were examined i n some detail using two methods. First, the three primary types of sondes u sed over the North Atlantic Ocean (Vaisala rawinsondes and the new and old generation Vaisala dropsondes) were intercompared. Some initial evidence wa s found of biases in the dropsonde data depending on the type of expendable used and the temperature regime. Second, to further clarify these biases a comparison of the precipitable water content calculated from the rawinsond es and dropsondes with that derived from SSM/I measurements was conducted. The results from this verified many of the conclusions of the initial inter comparison and brought additional insight. The FASTEX dataset is one of the most rich and varied datasets focusing on the North Atlantic. The data are readily accessible to the scientific commu nity at the FCA via the World Wide Web at: http://www.cnrm.meteo.fr/fastex/ .