TY - CHAP A1 - Jahr, Andreas A1 - Batos, Andrej A1 - Sim, Hunn A1 - Villena Martínez, Jose David T1 - A New Approach for Measuring the Wear Resistance of Cutter Blades T2 - International Conference of Agricultural Engineering – CIGR-AgEng2012, Valencia/Spanien, 8.-12.07.2012 Y1 - 2012 ER - TY - CHAP A1 - Jahr, Andreas A1 - Batos, Andrej A1 - Pillmann, A. A1 - Hoppe, S. A1 - Diett, D. T1 - Determining the Cutting Properties of Agricultural Products T2 - International Conference of Agricultural Engineering – CIGR-AgEng2012, Valencia/Spanien, 8.-12.07.2012 Y1 - 2012 ER - TY - CHAP A1 - Vogel, Andreas A1 - Weber, Konradin A1 - Eliasson, Jonas A1 - Palsson, Asgeir A1 - Moser, H. M. A1 - Palsson, Thorgeir A1 - von Löwis, S. A1 - Fischer, Christian T1 - Airborne and groundbased measurements of ash particles on Iceland and over Germany during the Grímsvötn eruption May 2011 [Abstract] T2 - Geophysical Research Abstracts:EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria N2 - The eruption of the Grimsvötn 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 Hvollsvöllur) 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 Grimsvötn 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. KW - Luftreinhaltung Y1 - 2012 UR - https://meetingorganizer.copernicus.org/EGU2012/EGU2012-12854-1.pdf SP - 12854 PB - Copernicus CY - Göttingen ER - TY - CHAP A1 - Weber, Konradin A1 - Reichardt, R. A1 - Fischer, Christian A1 - Moser, H. M. A1 - Eliasson, Jonas ED - Jha, Manoj K. ED - Lazard, Myriam ED - Zaharim, Azami ED - Sopian, Kamaruzzaman T1 - Computational Visualization of Volcanic Ash Plume Concentrations Measured by light Aircrafts over Germany and Iceland during the Recent Eruptions of the Volcanoes Eyjafjallajökull and Grimsvötn T2 - Recent advances in Fluid Mechanics, Heat & Mass Transfer, Biology and Ecology KW - Luftreinhaltung KW - Vulkanasche KW - Visualisierung KW - Eyjafjallajökull KW - Atmosphärisches Aerosol Y1 - 2012 SN - 978-1-61804-065-7 SP - 236 EP - 240 PB - WSEAS ER - TY - CHAP A1 - Weber, Konradin A1 - Vogel, Andreas A1 - Reichardt, Roland A1 - Zimmermann, Thomas ED - Altawell, Najib ED - Konstantin, Volkov ED - Cristina, Matos ED - Fernandez de Arroyabe, Pablo T1 - Research aircraft flight for gas leakage investigation at the Elgin wellhead gas platform in the North Sea – initial results T2 - Recent Researches in Environmental and Geological Sciences KW - Luftreinhaltung KW - Forschungsflugzeug KW - Messtechnik KW - Bohrinsel KW - Leckage KW - Erdgas Y1 - 2012 SP - 240 EP - 243 PB - WSEAS ER - TY - CHAP A1 - Vogel, Andreas A1 - Weber, Konradin A1 - Fischer, Christian A1 - Prata, A. J. A1 - Durant, A. J. T1 - Aircraft in situ and remote sensing measurements of emissions from Etna volcano, Sicily T2 - Geophysical Research Abstracts: EGU General Assembly 2012 N2 - 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. KW - Luftreinhaltung KW - Forschungsflugzeug KW - Messtechnik KW - Telemetrie KW - Schwefeldioxid KW - Vulkanismus KW - Atmosphärisches Aerosol Y1 - 2012 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Weber, Konradin A1 - Eliasson, J. A1 - Vogel, A. A1 - Fischer, C. A1 - Pohl, T. A1 - van Haren, G. A1 - Meier, M. A1 - Grobéty, B. A1 - Dahmann, D. T1 - Airborne in-situ investigations of the Eyjafjallajökull volcanic ash plume on Iceland and over north-western Germany with light aircrafts and optical particle counters JF - Atmospheric Environment KW - Luftreinhaltung Y1 - 2012 U6 - https://doi.org/10.1016/j.atmosenv.2011.10.030 SN - 1352-2310 VL - 48 SP - 9 EP - 21 PB - Elsevier ER - TY - CHAP A1 - Fischer, C. A1 - Pohl, T. A1 - Weber, Konradin A1 - Vogel, A. A1 - van Haren, G. A1 - Schweikert, W. ED - Lewis, Colin ED - Burgess, Douglas T1 - TATP stand-off detection with open path: FTIR techniques T2 - Optics and photonics for counterterrorism, crime fighting and defence VIII : 24 - 26 September 2012, Edinburgh, United Kingdom KW - Luftreinhaltung Y1 - 2012 SN - 978-0-8194-9287-6 U6 - https://doi.org/10.1117/12.974592 SN - 0277-786X VL - 8546 PB - SPIE CY - Bellingham, Wash ER - TY - JOUR A1 - Leadbetter, S. J. A1 - Hort, M. C. A1 - von Löwis, S. A1 - Weber, Konradin A1 - Witham, C. S. T1 - Modeling the resuspension of ash deposited during the eruption of Eyjafjallajökull in spring 2010 JF - Journal of Geophysical Research: Atmospheres N2 - Eyjafjallajökull, a volcano in southern Iceland, erupted explosively in April and May 2010 depositing ash over a region of more than 3000 km2 to the east and southeast of the volcano. This deposited ash has been frequently remobilized by the wind causing concern for the health of Icelanders living in the region. An investigation was carried out to determine whether it would be possible to produce forecasts of days when high airborne ash concentrations were likely to occur. Information about the spatially varying surface characteristics of the region of deposited ash is not available so in the modeling approach adopted here ash is released from the surface at a rate proportional to the cube of the excess friction velocity (local friction velocity minus a threshold) only when the friction velocity exceeds a threshold. Movement of the resuspended ash is then modeled in a Lagrangian dispersion model. Modeled ash concentrations are compared to observed concentrations from two periods; PM10 observations between 23 May and 2 July 2010 and airborne particle counts between 21 September 2010 and 16 February 2011. More than 66% of the resuspension episodes between May and July are captured by the model and the relative magnitudes of the modeled episodes in this period are in good agreement with the observations. 66% of episodes between October and February are also captured by the model although there is an increase in the false alarm rate which appears to be due to the influence of precipitation. KW - Luftreinhaltung Y1 - 2012 U6 - https://doi.org/10.1029/2011JD016802 SN - 0148-0227 VL - 117 IS - D20 PB - American Geophysical Union (AGU) ER - TY - JOUR A1 - Nehr, Sascha A1 - Bohn, Birger A1 - Wahner, Andreas T1 - Prompt HO2Formation Following the Reaction of OH with Aromatic Compounds under Atmospheric Conditions JF - The Journal of Physical Chemistry A KW - Luftreinhaltung Y1 - 2012 U6 - https://doi.org/10.1021/jp210946y SN - 1089-5639 VL - 116 IS - 24 SP - 6015 EP - 6026 PB - American Chemical Society (ACS) ER -