7                                           FORECASTING AT SPECIFIC LOCATIONS

7.1                                   The scope of this chapter

This section of the Handbook reports on the forecasting techniques and experiences of many of the nations that provide forecasting services for stations or expeditions in the Antarctic and on the sub–Antarctic islands. Our goal has been to try and bring together local knowledge that will be of value to new forecasters joining a station and/or when forecasts have to be provided for unfamiliar areas. The structure of each of this chapter’s sub–sections is similar. Information is discussed under the following headings: orography and the local environment; operational requirements and activities relevant to the forecasting process; data sources and services provided; and important weather phenomena and forecasting techniques used at the station. The last topic is further sub-divided under the headings of: general overview; surface wind and pressure field; upper wind, temperature and humidity; cloud; visibility; surface contrast including white–out; horizontal definition; precipitation; temperature and chill factor; icing; turbulence; hydraulic jumps; sea ice; wind waves and swell.

In compiling the information care was taken to obtain accurate data, however, there appear to be some instances of conflicting information in the literature. Where data such as location, elevation and station activities were not directly available from a contributor of the country, which operates a particular station, information was mostly obtained from the Council of Managers of National Antarctic Programs via http://www.comnap.aq .

Table 7.1.1 (located in Appendix 1 for convenience) is a comprehensive list of stations and AWSs in the Antarctic. The table shows the WMO number (or Argos number in the case of AWS reporting via the NOAA satellite system), location, elevation, name of the station or AWS, the country responsible for the station or AWS, and finally, the sub–section of this handbook where some aspects of the station are discussed.

The variety in map types and styles, which are presented in this chapter, are primarily the result of the disparate nature of data, which are available from relevant sources and literature. While Figure 1.2 (in Chapter 1) is a map of the Antarctic showing the principal regions and a selection of the research stations discussed, we present in Chapter 7 regional maps (scale 1:20 million at 71º S) showing the location of many of the stations and features discussed in each section: see, for example, Figure 7.2.1.1.1, which is a location map for the Falkland Islands and South Georgia area, and which shows how Drake Passage separates the Antarctic Peninsula from South America. Finer‑scale maps/diagrams are also presented, where available, to highlight small–scale orographic or topographic features in the immediate vicinity of stations (see, for example, Figure 7.3.2.1.1, which is a map of King George Island).

The climate tables and diagrams referred to throughout Chapter 7 are of a similarly disparate nature due to the variety of sources. In general these data, while referred to in Chapter 7, are actually shown collectively in Appendix 2 (see, for example, the average wind speed data for Kerguelen Island in Table 7.2.7.4.1).