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ePaper created 2013-08-02, 08:40:53 | version 1.25.20
2|2013 Research in Jülich 21 tector chips. Friedl-Vallon suggested using an imaging Fourier spectrometer. Atmospheric researchers from both institutions were involved in the techni- cal development right from the start. The optical system was developed at Karlsruhe, while specialists from Jülich developed and fabricated the appropri- ate electronics and mechanics. Reading out and processing more than ten mil- lion units of information per second is a challenge. BEAD CURTAIN IN THE SKY GLORIA is able to keep a measuring field steady within 50 metres on the horizon for ten seconds. Each measurement maps a vertical area of four kilometres up to the flying altitude. The points of each measurement are beaded together like a string of pearls. The next measure- ment is taken ten seconds later: target- ing the next field, holding for ten sec- onds, and then taking the measurement, heading for the next field, holding, meas- uring... The result resembles a bead cur- tain consisting of several million measur- ing points. This provides the researchers with a complete picture of the chemical composition of the targeted air masses. But GLORIA can do much more than that: if the aircraft flies in a large closed hexagon, the spectrometer turns into a three-dimensional tomography system. Dr. Peter Preusse from Jülich’s Institute of Energy and Climate Research (IEK) says, “This enables us to see the struc- ture of fluxes between the troposphere and stratosphere in three dimensions.” Prof. Martin Riese, Erik Kretschmer, and Felix Friedl-Vallon (from left to right) are enthusiastic about the huge amounts of data brought home by GLORIA from the most recent measurement campaigns. The secret to success: outstanding teamwork between all the institutions involved. However, on this day, 30 August, GLORIA is no longer in operation. “GLO- RIA had been tested and given clear- ance, also for electromagnetic interfer- ence fields,” says Tom Neubert from Jülich’s Central Institute of Engineering, Electronics and Analytics (ZEA). And in- deed, the pilots soon give the all-clear signal. The reason was obviously some- thing else, and GLORIA can be switched on again. But how? GLORIA has cooled down too much. The sensitive electron- ics have packed up. SIMPLE TRICK Both the ground crew and Erik Kretsch- mer are working feverishly to find a solution. The aircraft is reducing the flight level in order to enter warmer lay- ers of air. “We then asked Erik to switch on different units of GLORIA one after the other in order to produce heat first. By switching on the ventilators that are usually responsible for cooling, we dis- tributed the heat in the spectrometer,” says Tom Neubert. Success! From then on, GLORIA continues to reliably acquire data on the content of carbon dioxide, methane, ozone, water vapour, as well as numerous nitrogen and chlorine com- GLORIA stands for ‘Gimballed Limb Observer for Radiance Imaging of the Atmosphere’. It’s the name of a novel infrared camera that breaks down the heat radiation of atmospheric gases and aerosols into its spectral colours. The images produced show the large-scale movements of the different components of the atmosphere. GLORIA’s measurements include CO2, methane, ozone, water vapour, and numerous nitrogen and chlorine compounds. It is the prototype of a spectro- meter that could also be used on a satellite. pounds in the boundary region between the troposphere and the stratosphere. The flight routes of the measurement campaigns in autumn 2012 stretched from the Arctic Circle to the Svalbard ar- chipelago and around Africa to the Ant- arctic Circle. On every one of its flights, GLORIA collects one to two terabytes of data. The total sum will be 30 terabytes, which corresponds roughly to the amounts of data contained in three mil- lion encyclopaedias. NEW DETAILS The detailed analysis of the data is ex- pected to take at least until autumn 2013. Dr. Peter Preusse says, “Initial re- sults from GLORIA show that tropo- spheric and stratospheric air masses do not mix evenly. We found more pro- nounced structures than predicted by models. We observed the formation of filaments that are several 100 to 1,000 kilometres long, but only have a low ex- tent in altitude. GLORIA’s particularly high resolution allows us to observe these fine patterns in more detail than ever before.” :: Brigitte Stahl-Busse Masterpiece for climate research RESEARCH AT THE CENTRE | Climate Research