Friday, 23 December 2011

The BELATMOS measurements have restarted

Since mid-November Princess Elisabeth Antarctica is again operational. On the special website of the station ( you can follow the story. Erik, the engineer also responsible for taking care of the scientific equipment, restarted our instruments already. The TEOM-FDMS, the aethalometer, and the Brewer ozone spectrophotometer are operational again. The TEOM-FDMS and the aethalometer collected data also during winter, at least as long as electricity was there. This is something very interesting because the two instruments collected data when there was no station activity and when there was really no emission of aerosols for energy generation (only wind power and batteries). Data of this kind is rarely sampled in Antarctica. In one of my next posts I will tell a bit more about these data. The forth instrument, the Cimel sunphotometer, will arrive these days at the station and if weather allows, it will also be installed soon after.

The ozone spectrophotometer did already its first measurements, from 13 December onwards. On 14 and 15 December, the values for total atmospheric column ozone were really low, between 220 and 240 Dobson Units, before climbing the next days higher (see bottom image). On the image in the middle it can be seen that it fitted to the overall pattern of total ozone in the Southern Hemisphere. That image is a composite of measured total ozone values from observation stations worldwide (World Ozone and UV Data Centre), to which also our instrument contributes. The area of lowest total ozone was located on 14 December over East Antarctica and Dronning Maud Land. The black spot depicts the approximate location of Princess Elisabeth station. The upper image shows the UV index for that day. It is very high to extreme around local noon. These high UV values can be explained by the low total ozone values, the elevation of the station (1400 m) and the almost aerosol free atmosphere. They are also particular because the elevation of the sun (elevation above horizon) is not that high, although it is austral summer and near to summer solstice – on 14 December the elevation angle reached only 41deg. This is low compared to late spring, summer in our northern midlatitudes. And then the UV index in our region only rarely reaches values of 8/9. It means that the sun poses really a danger in Antarctica. Although the ozone hole period is over now in Antarctica, there are still large areas with low total ozone values, as can be seen in the middle image.

Merry Christmas and till soon