After
the last team left Princess Elisabeth station (visit the station blog antarcticstation.org), the station and also
its scientific instrumentation is now completely in automatic and remote
control mode. Until now, all instruments have continuously been working and are
doing this also right now. The sunphotometer and the Brewer spectrophotometer
however, have been dismounted end of February by Erik. The sunphotometer
travels back to Europe for the yearly calibration and the Brewer is stored inside
the station. In principle, it could be operated continuously, but as its
optical part is very sensitive it would be too risky to leave it running. If
anything happened to the instrument’s mechanics or optics, there would be
nobody to repair it. This will possibly damage the whole instrument and repair
or replacement would be an immense cost. All the six other instruments will
continue to record and send data, as long as there is no power break down or
failure of an instrument part. In the southern scientific shelter, the five
aerosol instruments (TEOM-FDMS aethalometer, nephelometer, laser aerosol
spectrometer, condensation particle counter) are now in their forth month of
simultaneous operation. The condensation particle counter has got his larger
reservoir for n-butanol supply during the long winter period, and the
nephelometer has been calibrated a last time before the end of the season. Such
a calibration is done with a pure reference gas, in our case extremely pure
carbon dioxide. The amazing thing of remote control is that I could do some
nephelometer calibration from my desk in Brussels. This needed of course some
cooperation with Erik at the station who opened the gas bottles and some
valves, but the exact calibration I controlled via remote desktop connection to
the controlling desktop in the shelter which in turn is connected via a serial
port to the nephelometer control port. As it is too risky to leave an open gas
bottle nine months unattended, a full calibration will not be possible anymore.
But a so-called zero-check (with ‘zero’, filtered air via an internal filter)
of the calibration regression can always be done remotely. In the next entry to
this blog I will show some exemplary graphs of the aerosol data. The images
above show the instruments at the end of the season: the Brewer
spectrophotometer and the elevated box with sensors for total solar and UV-A,
UV-B irradition on the northern station roof; the Cimel sunphotometer; and the
five aerosol instruments in southern shelter (order from left to right like
mentioned above).
