1                                           INTRODUCTION

Forecasts of the weather over the Antarctic have been made since the first expeditions to the continent, although in the early years the success of these predictions was poor since few observations were available and there was only a rudimentary understanding of the workings of the high latitude climate. This situation changed little until the International Geophysical Year (IGY) of 1957–58 when a number of research stations were established across the Antarctic, with many of these making routine radiosonde ascents. These additional data allowed more reliable surface and upper–air analyses to be prepared, although there were still few observations over the ocean areas. Since IGY there have been a number of major advances that have greatly aided weather prediction over the continent. Since the 1960s satellite imagery has been an extremely important tool in identifying the locations of synoptic and mesoscale weather systems over the ocean areas and the continent itself. Although the early imagery was poor with a coarse resolution and few grey–scales, today many stations have digital receivers capable of providing high–resolution images at several wavelengths. These images can provide early warning of approaching weather systems, fronts and isolated cloudbanks, as well as supplementary information on sea ice extent. Figure 1.1 is an example of satellite thermal infra–red (TIR) imagery coverage of Antarctica overlaid with a surface pressure analysis.

Objective information on upper–level temperature and humidity has also been produced from satellite sounder data since the late 1970s and these data have been essential for the computer analysis of atmospheric conditions at high southern latitudes. Such data allowed the implementation of global numerical weather prediction (NWP) systems that could provide forecasts out to about a week ahead. During the 1980s the accuracy of Antarctic forecasts from such NWP systems was much lower than those for tropical and mid–latitude areas, but during the 1990s there have been marked improvements as a result of better analysis techniques, higher model resolution and additional data from new satellite instruments, such as the wind scatterometer. 

As Antarctic weather forecasting techniques were developed by the various nations involved in operations on the continent, so a number of forecasting manuals and handbooks were developed. These were often used to train new forecasters going “South” and to build up information and knowledge gained by successive generations of forecasters. These books were often concerned with specific areas of the Antarctic and were usually focussed on the forecasting needs of the particular nation, these needs often being aviation or marine forecasting. Such volumes had a limited circulation and there was little interchange of information on forecasting between nations. However, today Antarctic logistics are very complex with scientists working in remote parts of the continent, flights taking place throughout the year and thousands of tourists visiting the continent each summer. There is therefore a pressing need for accurate weather forecasts for the continent and good exchange of information between forecasters working in the Antarctic.

This handbook has been written following the successful First International Symposium on Operational Weather Forecasting in the Antarctic, which was held in Hobart, Australia between 31 August and 3 September 1998 (Turner et al., 2000a). This meeting brought together practicing forecasters with Antarctic experience, administrators responsible for providing forecasting services for Antarctic operations, developers of numerical models and researchers with a close interest in weather forecasting. The attendees came from Australia, Belgium, Brazil, China, France, Italy, Russia and the United Kingdom (UK) so that a great deal was learnt about the forecasting operations taking place in the Antarctic and the techniques used at the various stations. A major outcome of the symposium was the decision to prepare this handbook to aid the interchange of forecasting techniques, to provide information for use when forecasting for an unfamiliar area and for training purposes.


Figure 1.1     Composite of geostationary and polar orbiting infra–red satellite imagery for the nominal time of 0000 UTC 4 July 1994. (The imagery is courtesy of the University of Wisconsin–Madison's Space Science and Engineering Center. The analysis overlay was produced during the First Regional Observing Study of (the Antarctic) Troposphere Project.)

The handbook splits into two main sections. Chapters 1 to 6 provide general background on the meteorology and climatology of the continent, the requirement for forecasts, data availability and characteristics, and general information on the analysis and forecasting techniques applicable to the Antarctic. Chapter 7 gives details information on the meteorology of all the main areas of the continent for which weather forecasts are issued, along with local forecasting techniques used. Data are also provided for many of the sub‑Antarctic islands. Figure 1.2 shows the geographical area of prime interest considered in the handbook.

Figure 1.2     A map of the Antarctic showing the principal regions and a selection of the research stations. (Courtesy of the British Antarctic Survey.)