Surface Synoptic Database

The most important change in observing practice has been the changeover from manual to automatic observing systems to perform many routine synoptic observations. This change occurred in the mid-1980s at Halley and Faraday and more recently at Signy Island and Rothera Point, and involved the deployment of SCAWS (Synoptic and Climatological Automatic Weather Station) which was replaced in 1992 by MAWS (Modular Automatic Weather Station).

Apart from standard checks to the data, e.g. for extreme values, including those due to equipment malfunction, and incorrect codes, the experience of trained meteorological observers in addition to further scrutiny of some of the data suggests that the performance of automatic weather stations and instruments after initial installation has been satisfactory. Instruments are regularly and frequently calibrated. Regular on-site monitoring of the performance of SCAWS and MAWS by observers, including comparisons with measurements from standard meteorological equipment, also appears to have prevented systematic errors in measurement.