The Antarctic Plateau is by far the coldest, the driest, the highest and the most isolated continent on Earth. It is the most promising site for IR, millimeter and radio observations. The average elevation is more than 2000 m, with an equivalent pressure of a higher site, because of the reduced thickness of the atmosphere at the Poles. The average Precipitable Water Vapour (PWV) content is less than 0.5 mm and average wind speed is reported to be 10 m/s. A good observing site, such as Mauna Kea, could reach these low values only in few, extremely good nights. These conditions produce an average transmission, at millimetric wavelengths, greater than 90%. Dome C average conditions are reported in Table 1.
Table 1: General characteristics of the observing site, Dome C, Antarctica
Moreover, the geographical position of Dome C, in the highest part of the Antarctic plateau, is at the borders of the antarctic wind circulation pattern. Therefore, a laminar flow is present due to settling of the cold air and exceptionally stable atmospheric conditions are expected, especially during the antarctic winter.
Dome C station, during this first mission, was able to support only small experiments and few researchers.
Figure 1: APACHE96 at Dome C, December 1996.
APACHE96 was assembled at Terra Nova Bay station (the italian base on the coast) and then transferred at Dome C by a small airplane (Figure 2).
Figure 2: The Twin Otter plane during refueling on the Antarctic Plateau.