The Leicester Aatsr Global Analyser (laga) - Quick-look Analysis of Large-scale Oceanic Processes

A PC-based utility has been devised for the rapid display and preliminary analysis of long time-series of satellite data such as, for example, the 16-year series of monthly mean global fields of SST measured by the ATSR series of instruments. This utility gives investigators immediate access to the data, which are presented in the form of monthly averages and spatial averaged to half-degree or onesixth degree longitude-latitude grids. There are simple button-operated facilities for defining and calculating box-averages; producing time-series of such averages; defining and displaying transects and their evolution over time; and the examination of anomalous behaviour by displaying the difference between observed values and values derived from climatological means. By using these facilities an investigator rapidly gains familiarity with such processes as annual variability, the El Niño effect and major current systems such as the Gulf Stream and other climatically important phenomena. The capabilities of the software package will be explained and examples of its output will be shown. It will be seen that LAGA provides a rapid introduction to the data and to the oceanic processes that are observed. Although it can be used by any investigator who needs a 'quick look', it is particularly well suited to new investigators or students.