The scientific context in which these meteorological observations are undertaken is for the detection and characterization of global changes in Antarctica.
The Antarctic environment is thought to be particularly sensitive to climatic changes: the mechanisms by which Antarctica might have a considerable influence
on global changes include the ice-albedo feedback and the modification of the mass balance of the Antarctic ice cap, for example. Numerical climatological
models do not correctly simulate these phenomena.It is therefore essential to monitor the effects of climatic variations in Antarctica, by means of time
scales varying from a few years to several decades. This is necessary due to the considerable lack of measurement sites on the mainland and surrounding oceans,
while satellite-based measurement need to be calibrated through surface observations.
Of climatic variables that are monitored, surface temperature, cloud cover and precipitation are key parameters. Atmospheric dynamics and general air circulation
need to be monitored as well, as they are important elements of the climatic system. Heat transport (sensible and latent) from and towards the Pole, operated by
mesoscale cyclones; dense water production occurring in coastal polynyas forced by winds; and the contribution of precipitation to the mass balance, represent
some of the processes in which the detailed knowledge of atmospheric dynamics and vertical structure plays a primary role.
The main goal of the meteorological observatory is the collection of continuous and accurate measurements. This will produce a data set that could be used for
meteo-climatological and atmospheric studies, local weather forecasting, and supporting scientific activities that use meteorological data. Therefore, during
Antarctic expeditions, the main jobs are to carry out the maintenance of the automatic weather survey stations, recover the data collected locally by solid state
memories (ground data), undertake atmospheric soundings (in order to collect data from upper atmospheric layers), and maintain equipment used in the Terra Nova Bay
Besides checking the mechanical installations (mast, batteries, etc.), the maintenance normally includes the control of the electronic parts (data acquisition system,
central processing unit, etc.) and the sensors. The values of pressure, temperature and relative humidity are compared with those measured by calibrated instruments.
Wind speed and direction sensors that are not working correctly, due to deterioration of moving mechanical parts, are replaced. Recently, stations located on the
Antarctic Plateau were equipped with sensors for the measurement of snow accumulation/ablation.
In 1987, an atmospheric radiosounding station was installed, at the meteorological laboratory of the Italian base. The system includes a meteorological station
for data collection at ground level and a receiving ground station (VAISALA Marwin 12), which receives data transmitted via radio by the sonde and stores them
in a computer with dedicated software that shows the real-time trend of the measured parameters. The data received are stored in ASCII files, and then coded in
the standard meteorological format TEMP, to be sent to the Global Communication System of the World Meteorological Organization (WMO-GTS). While in Antarctica,
two balloons are launched every day at 00:00 and 12:00 UTC to measure temperature, pressure relative humidity and wind between 20 and 30km high.
During the operation of the runway in Tethys Bay, Terra Nova Bay meteorological office needs particular instruments to complete the information that is to be
communicated to the pilots during approach and landing. As a result, at the beginning of each expedition a CT12K VAISALA ceilometer is installed to measure
the height of the cloud base and, a couple of anemometric towers (Alfa and Bravo) are installed to measure wind speed and direction. These instruments are
connected to monitors in the Meteorological Office via modem (ceilometer) and via radio (anemometer).