Friday, 27 February 2015

All under remote control

Time has been flying and in the meantime it is end of February 2015. Princess Elisabeth station is uninhabited since two days. During the past two months, Johnny, the station’s main engineer, took care of our instruments and also of the balloon radio soundings. All instruments have been operating fine, including the sunphotometer. At the very last days of Quentin’s and my stay we managed to get the sunphotometer operational. It appeared to be an ordinary power issue – a loose contact at the battery. It is very good that this instrument has done measurements now for two months – for the vast Antarctic continent there are very few of its kind installed, although its main output, the aerosol optical depth (AOD) is a widely used parameter in global chemical transport models. Our other problem child, the size distribution instrument, had itself no failure. But, unluckily, during a storm in mid-January very little snow intruded into the aerosol measurement container, however, exactly onto the laptop which was used for that instrument. Snow smelts and thus the laptop broke… Nevertheless, help arrived with a feeder flight beginning of February. That flight brought in Stephan Bracke from RMI’s department in Dourbes. He came for installing new instrumentation for Geomagneticobservations. But he also brought with him a new laptop for running the aerosol size distribution instrument. So, we were lucky to have at least a total of 6 weeks of data from this instrument. At the end of the season, Johnny dismounted it and it will be repaired and calibrated in order to be re-installed during summer season 2015-2016. Like this instrument, also the Cloud Condensation Nuclei counter (CCNc) of TROPOS (Leipzig, Germany) and the sunphotometer will be shipped back. The sunphotometer will undergo its yearly calibration (in addition, there is hardly enough sun for it during winter) and the CCNc will be used for other measurement campaigns (and hopefully will be back next season). The Brewer ozone spectrophotometer also has been dismounted. It could continue with its measurements automatically, however, its mechanics and optics are very sensitive. If anything happens during the winter months – there is nobody to quickly stop it or repair it – and the risk is too high that this very expensive instrument encounters serious damage. It is stored safely in PE until next season. The ground equipment and antennas for the radio soundings are also shipped back to Brussels. We want to compare some of these radio sondes with the radio sondes type we are using operationally in Brussels. This will help to raise the confidence and accuracy of the radio sondes’ data. Altogether, this meant a lot of dismounting and packing work for Johnny. And a lot of cargo-customs-paper work for me. Now, there remain four aerosol instruments operational – the TEOM-FDSM, the aethalometer, the nephelometer and the condensation particle counter. At this place I want to express my gratefulness to Johnny who took great care of all the instrumentation! Now lets keep fingers crossed that everything goes well down there in the Antarctic.