@article{BirmiliRehnVogeletal.2013, author = {Birmili, Wolfram and Rehn, Johanna and Vogel, Andreas and Boehlke, Christoph and Weber, Konradin and Rasch, Fabian}, title = {Micro-scale variability of urban particle number and mass concentrations in Leipzig, Germany}, series = {Meteorologische Zeitschrift}, volume = {22}, journal = {Meteorologische Zeitschrift}, number = {2}, publisher = {Borntr{\"a}ger}, doi = {10.1127/0941-2948/2013/0394}, pages = {155 -- 165}, year = {2013}, language = {en} } @article{EliassonWeberVogeletal.2016, author = {El{\´i}asson, Jonas and Weber, Konradin and Vogel, Andreas and P{\´a}lsson, Thorgeir and Yoshitani, Junichi and Miki, Daisuke}, title = {Investigation and Separation of Turbulent Fluctuations in Airborne Measurements of Volcanic Ash with Optical Particle Counters}, series = {Journal of Disaster Research}, volume = {11}, journal = {Journal of Disaster Research}, number = {1}, publisher = {Fuji Technology Press Ltd.}, issn = {1883-8030}, doi = {10.20965/jdr.2016.p0072}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50023}, pages = {72 -- 84}, year = {2016}, abstract = {The science of measuring airborne volcanic ash concentrations supports research in such fields as atmospheric environmental science and the modeling of atmospheric pollution from volcanoes, and is thus very valuable to the aviation industry. These measurements show large scatter directly traceable to turbulent fluctuations responsible for diffusing volcanic dust. Before semistationary components in observations can be compared to each other or to simulation results, they must be separated from fluctuations. In the design of the separation process, however, neither seasonal or diurnal periodicity nor random disturbance with known properties exists to serve as a guideline. It has been suggested that fluctuations could be eliminated through repeated convolutions of a simple 3-point filter enough times. The number of convolutions is chosen from the change in the rate of increase of a special variability parameter. When semistationary concentrations are separated from fluctuations, their statistics are compared to turbulence parameters and the autocorrelation of the series. The method is demonstrated using three measurement series from Sakurajima, Japan measured in 2013. It is concluded that this new method is simple and trustworthy where knowledge and experience of the environmental parameters can be utilized to support the results. They indicate a variability of 40\% in the relative fluctuations of the PM10 and around 20\% of the PM2.5. The relative fluctuations may be considered completely random, but normally distributed rather than a white noise with an evenly distributed variance spectrum.}, language = {en} } @inproceedings{WeberVogelFischeretal.2010, author = {Weber, Konradin and Vogel, Andreas and Fischer, Christian and van Haren, G{\"u}nther and Pohl, Tobias}, title = {Airborne measurements of the Eyjafjallaj{\"o}kull volcanic ash plume over northwestern Germany with a light aircraft and an optical particle counter: first results}, series = {Lidar technologies, techniques, and measurements for atmospheric remote sensing VI : 20 - 21 September 2010, Toulouse, Franc}, volume = {7832}, booktitle = {Lidar technologies, techniques, and measurements for atmospheric remote sensing VI : 20 - 21 September 2010, Toulouse, Franc}, number = {7832OP}, editor = {Singh, Upendra N. and Pappalardo, Gelsomina}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {978-0-8194-8349-2}, issn = {0277-786X}, doi = {10.1117/12.869629}, year = {2010}, language = {en} } @article{EliassonYoshitaniWeberetal.2014, author = {Eliasson, Jonas and Yoshitani, Junichi and Weber, Konradin and Yasuda, Nario and Iguchi, Masato and Vogel, Andreas}, title = {Airborne Measurement in the Ash Plume from Mount Sakurajima: Analysis of Gravitational Effects on Dispersion and Fallout}, series = {International Journal of Atmospheric Sciences}, volume = {2014}, journal = {International Journal of Atmospheric Sciences}, publisher = {Wiley}, issn = {2314-4122}, doi = {10.1155/2014/372135}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50955}, pages = {16}, year = {2014}, abstract = {Volcanic ash concentrations in the plume from Sakurajima volcano in Japan are observed from airplanes equipped with optical particle counters and GPS tracking devices. The volcano emits several puffs a day. The puffs are also recorded by the Sakurajima Volcanological Observatory. High concentrations are observed in the puffs and fallout driven by vertical air current, called streak fallout. Puffs dispersion is analyzed by the classical diffusion-advection method and a new gravitational dispersion method. The fluid mechanic of the gravitational dispersion, streak fallout, and classical diffusion-advection theory is described in three separate appendices together with methods to find the time gravitational dispersion constant and the diffusion coefficient from satellite photos. The diffusion-advection equation may be used to scale volcanic eruptions so the same eruption plumes can be scaled to constant flux and wind conditions or two eruptions can be scaled to each other. The dispersion analyses show that dispersion of volcanic plumes does not follow either theories completely. It is most likely diffusion in the interface of the plume and the ambient air, together with gravitational flattening of the plumes core. This means larger boundary concentration gradients and smaller diffusion coefficients than state of the art methods can predict.}, subject = {Vulkanismus}, language = {en} } @inproceedings{WeberFischerVogeletal.2013, author = {Weber, Konradin and Fischer, Christian and Vogel, Andreas and Pohl, Tobias and B{\"o}hlke, Christoph and Lau, Hendrik and Eliasson, Jonas and Palsson, Thorgeir}, title = {First results of an airborne release of volcanic ash for testing of volcanic ash plume measurement instruments}, series = {Recent Advances in Energy and Environmental Management}, volume = {Energy, Environmental and Structural Engineering Series 13}, booktitle = {Recent Advances in Energy and Environmental Management}, editor = {Mladenov, Valeri and Tasho, Tashev and Hui, Wang and Ivan, Kralov and Sergey, Stankevich and Pelin, Yildiz and Jon, Burley}, publisher = {WSEAS}, pages = {169 -- 172}, year = {2013}, subject = {Vulkanasche}, language = {en} } @article{EliassonYasudaWeberetal.2014, author = {Eliasson, Jonas and Yasuda, Nario and Weber, Konradin and Vogel, Andreas and Palsson, Thorgeir}, title = {The role of in-situ measurements of volcanic ash concentrations in preventing economic disasters due to volcanic ash clouds}, series = {Journal of Integrated Disaster Risk Management}, volume = {4}, journal = {Journal of Integrated Disaster Risk Management}, number = {1}, publisher = {Journal of Integrated Disaster Risk Management}, issn = {2185-8322}, doi = {10.5595/idrim.2014.0092}, pages = {48 -- 60}, year = {2014}, language = {en} } @inproceedings{WeberVogelReichardtetal.2012, author = {Weber, Konradin and Vogel, Andreas and Reichardt, Roland and Zimmermann, Thomas}, title = {Research aircraft flight for gas leakage investigation at the Elgin wellhead gas platform in the North Sea - initial results}, series = {Recent Researches in Environmental and Geological Sciences}, booktitle = {Recent Researches in Environmental and Geological Sciences}, editor = {Altawell, Najib and Konstantin, Volkov and Cristina, Matos and Fernandez de Arroyabe, Pablo}, publisher = {WSEAS}, pages = {240 -- 243}, year = {2012}, subject = {Forschungsflugzeug}, language = {en} } @inproceedings{VogelWeberFischeretal.2012, author = {Vogel, Andreas and Weber, Konradin and Fischer, Christian and Prata, A. J. and Durant, A. J.}, title = {Aircraft in situ and remote sensing measurements of emissions from Etna volcano, Sicily}, series = {Geophysical Research Abstracts: EGU General Assembly 2012}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2012}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2012}, abstract = {Volcanoes emit particles (silicates and sulphate aerosol) and gases (e.g., water and sulphur dioxide) which influence the radiative balance of the atmosphere. The rate at which sulphur dioxide oxidises to sulphate aerosol is poorly constrained and measurements of downwind abundance are required to quantify the rate at which this process occurs. During July and November 2011, a series of measurements were performed in emissions from Etna Volcano, Sicily, using the University of Applied Sciences (Dusseldorf) research aircraft. Both in situ and remote sensing instrumentation was simultaneously deployed to quantify the down-wind characteristics of gases and particles in the plume emitted by the volcano. In situ particle characteristics were measured using a Grimm 1.109 optical particle counter (microparticles 0.25-32 microns) and Grimm 1320 diffusion electrometer (nanoparticles 25-300 nanometers). Column abundance of sulphur dioxide was measured using a vertically-pointing differential optical absorption spectrometer (DOAS). These measurements were compared to horizontal pathlength-integrated measurements of sulphur dioxide from the Airborne Volcanic Imaging Object Detector (AVOID). Down-wind plume dispersion was discriminated through a series of aircraft transects below and through the volcanic plume. The emissions contained large amounts of nanoparticles relative to microparticles, which reflects gas-phase nucleation of sulphate aerosol. The AVOID system discriminated horizontal layering of volcanic aerosol at altitudes of up to 12,000 ft from a detection range of >50 km. Plume boundaries were discriminated using a combination of the in situ and DOAS measurements in order to compare to the pathlength-integrated measurements from AVOID.}, subject = {Forschungsflugzeug}, language = {en} } @inproceedings{WeberFischerLangeetal.2015, author = {Weber, Konradin and Fischer, Christian and Lange, Martin and Pohl, Tobias and B{\"o}hlke, Christoph and Wagner, Frank and Mattis, Ina and Flentje, Harald and Sturm, Klaus and Barth, Joachim and Steinkopff, Thomas and Vogel, Andreas}, title = {Aircraft measurements compared with ceilometer measurements during a sahara dust period in Germany}, series = {Geophysical Research Abstracts: EGU General Assembly 2015}, volume = {17}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2015}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2015}, abstract = {A significant Sahara dust event took place at the beginning of April 2014 over large areas of Germany and Europe. The German Weather Service (DWD) detected and monitored the expansion and propagation of this dust cloud with a ceilometer network of more than 50 ceilometers. Moreover, these ceilometers were also able to track the altitude of the dust cloud at the positions of the ceilometers. Additionally, aircraft measurements over Germany and France were performed with two aircraft by the Duesseldorf University of Applied Sciences. These aircraft were equipped with optical particle counters (OPC) and were able to measure the particle size distribution within the Sahara dust cloud and as a result of this to calculate the particle mass concentration of the dust. The ceilometer measurements and the aircraft measurements complemented each other: whereas the ceilometers gave continuous information about the Sahara dust cloud at the ceilometer positions, the aircraft measurements delivered interpolating results between the ceilometer positions. Moreover, at several ceilometer positions intercomparison flights were performed by spiraling with the aircraft up or down around the ceilometer laser beam. This gave the unique possibility for comparing the remote sensing results of the ceilometers with the in-situ measurements of the aircraft. This study shows that a significant high amount of Saharan dust particles was transported over Germany during a several days long episode. Furthermore, the intercomparison study between the German ceilometer network and aircraft measurements results shows a good agreement. A combination of these techniques could help to detect the vertical and horizontal distribution of the dust cloud and additionally the particle mass concentration.}, subject = {Deutscher Wetterdienst}, language = {en} } @inproceedings{VogelWeberFischeretal.2011, author = {Vogel, Andreas and Weber, Konradin and Fischer, Christian and van Haren, G{\"u}nther and Pohl, Tobias and Grobety, Bernhard and Meier, Mario}, title = {Airborne in-situ measurements of the Eyjafjalloj{\"o}kull ash plume with a small aircraft and optical particle spectrometers over north-western Germany - comparison between the aircraft measurements and the VAAC-model calculations}, series = {Geophysical Research Abstracts: EGU General Assembly 2011}, volume = {13}, booktitle = {Geophysical Research Abstracts: EGU General Assembly 2011}, publisher = {Copernicus}, address = {G{\"o}ttingen}, year = {2011}, abstract = {The eruption of the volcano Eyjafjallaj{\"o}kull (Iceland) in 2010 has caused a transportation of an ash dust plume over large areas of Europe. In April 2010 many airports in Europe were closed for several days because of the volcano ash plume and even in May 2010 several German and European airports were closed for shorter periods because of the danger caused by the volcanic ash dust. The VAAC (Volcanic Ash Advisory Center), London, has continuously published graphics of the predicted spread and dispersion of the volcanic ash plume, which were partly basis for the air traffic restrictions in Germany. In this situation the Laboratory for Environmental Measurement Techniques of the University of Applied Sciences in Duesseldorf has performed 14 measurement flights starting from April 23 2010 to May 21 2010 to get real airborne in-situ dust measurement data over the north-western part of Germany and for comparison with the predicted ash dispersion model data of the VAAC of London in Germany. Moreover, airborne passive DOAS remote sensing measurements have been performed by a mini-DOAS system for SO2-measurements within the plume. In this paper the results of the airborne optical ash particle measurements as well as the remote sensing SO2 measurements will be reported for situations with and without the volcanic plume over northern Germany in detail. Moreover, the measured dust data will be compared with the model dispersion predictions for the ash plume by the VAAC and with European limit concentrations. Main conclusions are: The „ash plume", found by the aircraft measurement of the Duesseldorf University of Applied Sciences over north western Germany in the "red zone" predicted by the VAAC turned out to be inhomogeneous during the measurement flights Clusters of ash plume sometimes had only a height extension of several hundred meters or less Ash substructures with a horizontal extension of ten kilometres up to several tenth of kilometres could be found Vertical double structures of ash plume could be measured by spiral flights and could be observed visually in horizontal direction Ash plume could be observed visually as small brown layer in horizontal direction Particles collected during flight could be identified as ash particles by electron microscope analysis and chemical analysis}, subject = {Vulkanasche}, language = {en} } @article{HeninPetitRohwetteretal.2011, author = {Henin, Stefano and Petit, Yannick and Rohwetter, Philipp and Stelmaszczyk, Kamil and Hao, Zuoqiang and Nakaema, Walter Morinobu and Vogel, Andreas and Pohl, Tobias and Schneider, Friedhelm and Kasparian, J{\´e}r{\^o}me and Weber, Konradin and W{\"o}ste, Ludger and Wolf, Jean-Pierre}, title = {Field measurements suggest the mechanism of laser-assisted water condensation}, series = {Nature Communications}, volume = {2}, journal = {Nature Communications}, number = {1}, publisher = {Springer Nature}, issn = {2041-1723}, doi = {10.1038/ncomms1462}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-52439}, year = {2011}, abstract = {Because of the potential impact on agriculture and other key human activities, efforts have been dedicated to the local control of precipitation. The most common approach consists of dispersing small particles of dry ice, silver iodide, or other salts in the atmosphere. Here we show, using field experiments conducted under various atmospheric conditions, that laser filaments can induce water condensation and fast droplet growth up to several μm in diameter in the atmosphere as soon as the relative humidity exceeds 70\%. We propose that this effect relies mainly on photochemical formation of p.p.m.-range concentrations of hygroscopic Hno3, allowing efficient binary Hno3-H2o condensation in the laser filaments. Thermodynamic, as well as kinetic, numerical modelling based on this scenario semiquantitatively reproduces the experimental results, suggesting that particle stabilization by Hno3 has a substantial role in the laser-induced condensation.}, subject = {Kondensation}, language = {en} } @inproceedings{VogelWeberEliassonetal.2012, author = {Vogel, Andreas and Weber, Konradin and Eliasson, Jonas and Palsson, Asgeir and Moser, H. M. and Palsson, Thorgeir and von L{\"o}wis, S. and Fischer, Christian}, title = {Airborne and groundbased measurements of ash particles on Iceland and over Germany during the Gr{\´i}msv{\"o}tn eruption May 2011 [Abstract]}, series = {Geophysical Research Abstracts:EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria}, booktitle = {Geophysical Research Abstracts:EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria}, publisher = {Copernicus}, address = {G{\"o}ttingen}, pages = {12854}, year = {2012}, abstract = {The eruption of the Grimsv{\"o}tn volcano in May 2010 posed with its ash plume a thread to the aviation in northern Europe. Because of ash plume forecasts of the VAAC London the airport of Keflavik in Iceland as well as airports in England, Scotland and Scandinavia were closed for some time, which caused the cancellation or change of about 500 flights in Europe. Even in Germany the airports of Bremen, Hamburg and Berlin were closed for several hours on 25 May 2011. During this eruption period in May 2011, a team of the Duesseldorf University of Applied Sciences, the University of Iceland, the University of Reykjavik and the IMO has performed airborne in-situ measurements over Iceland and Germany as well as ground based measurements in the south of Iceland. The ground based measurements were performed continuously during the whole eruption period at two significant positions (Skogar and Hvollsv{\"o}llur) with optical particle counters (OPCs). The measurement method was based on measuring the airborne concentrations of the classic aerosol components (PM10, PM2.5 and PM1) and TSP (total suspended particles) every 6 seconds. Additional measurement flights on Iceland were started already one day after the beginning of the eruption (twelve in-situ measurement flights) and marked the spatial and temporal spread of volcanic ash in the atmosphere. For the flights light slow flying piston engine powered airplanes where used. The flights over Iceland focused on the western part of Iceland in the region of Reykjavik and Keflavik and over the international airport in Keflavik and were mostly coordinated by ISAVIA. The measurement flights helped to keep Keflavik International Airport open for many additional hours despite of adverse predictions by the London VAAC model, because it was possible to observe the particle concentration on-line during the flights. In Germany a measurement flight was performed on 25 May 2012 over the northern part of Germany where the volcanic ash cloud was forecasted from the dispersion model of the London VAAC. This flight was performed on the behalf of the German Weather Service (DWD). The measurement flights revealed most time relative low airborne ash concentrations over western Iceland, although the groundbased measured ash concentrations in the south of Iceland nearer to the Grimsv{\"o}tn were very high. In Germany the measured concentrations during the flight were low enough to be consistent with the re-opening of the airports Bremen, Hamburg and Berlin, which were closed by the authorities for several hours on 25 May 2011 because of high concentration predictions by the VAAC-model. The measurement flights clearly proved that OPCs, based on slow flying piston-motor driven aircrafts, are very suitable for the determination of airborne ash particles during volcanic eruptions. This is an important issue for air traffic safety.}, language = {en} } @incollection{DoernerTeschRueggebergetal.2026, author = {D{\"o}rner, Ralf and Tesch, Alexander and R{\"u}ggeberg, Jim and Fuchs, Andreas and Grimm, Paul and Hillig, Julian and Pfeiffer, Thies and Blattgerste, Jonas and Bernloehr, Annette and Vogel, Kristina and Bauer, Nicola H. and Pestov, Alec and Spierling, Ulrike and Geiger, Christian and Hildebrand, Axel and Tropper, Tobias and Wilke, Wilhelm and Winkler, Christian and Makled, Elhassan and Schott, Ephraim and Broll, Wolfgang and Weidner, Florian and Fr{\"o}hlich, Bernd and G{\"o}bel, Gunther and Steinhauser, Marco and Schwandt, Tobias and Kumari, Gunjan and Stolz, Georg and Werner, Stephan and Uzun, Y{\"u}cel and Oppermann, Leif}, title = {Fallbeispiele f{\"u}r VR/AR}, series = {Virtual und Augmented Reality (VR/AR): Grundlagen und Methoden von Extended Realities (XR)}, booktitle = {Virtual und Augmented Reality (VR/AR): Grundlagen und Methoden von Extended Realities (XR)}, editor = {D{\"o}rner, Ralf and Broll, Wolfgang and Grimm, Paul and Jung, Bernhard}, publisher = {Springer Nature}, address = {Berlin, Heidelberg}, isbn = {9783662723081}, doi = {10.1007/978-3-662-72309-8_11}, pages = {579 -- 628}, year = {2026}, subject = {Virtuelle Realit{\"a}t}, language = {de} }