@article{PohlHewelingFischeretal.2017, author = {Pohl, T. and Heweling, G. and Fischer, C. and Weber, Konradin}, title = {Traffic Influenced Nitrogen Dioxide, Ultrafine Particle and Black Carbon Concentrations at a Busy Urban Street in Duesseldorf, Germany}, series = {International Journal of Environmental Science}, volume = {2}, journal = {International Journal of Environmental Science}, issn = {2367-8941}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50355}, pages = {410 -- 417}, year = {2017}, abstract = {In this study the road traffic related air pollution within a busy urban street canyon in the City of Duesseldorf, Germany was investigated. For the investigations the measurement truck of the laboratory for environmental measurement techniques of the HSD was equipped with different measurement devices for gaseous and aerosol species as well as meteorological sensors. The measurement truck was placed next to a stationary air quality measurement container of the Environmental State Agency of North-Rhine-Westphalia (LANUV). The measurement site is located at the Cornelius street, a direct north south connecting street through the city of Duesseldorf, which is highly frequented by road traffic with an daily amount of about 45,000 vehicles. The street is located within the low emission zone (LEZ). Additionally the pass through of vehicles with a higher weight than 7.5 tons is prohibited. Within this study over a period of several weeks the particle mass concentrations PM10, PM2.5 and PM1, and the particle number size distribution (PNSD) were measured over a broad range from 5 nm to 32 µm with a high temporal resolution. Additionally, an aethalometer was used to determine the proportion of black carbon in the particle ensembles. Gaseous pollutants like nitrogen dioxide, ozone and sulphur dioxide were measured as well. Nitrogen dioxide is a typical species originating from combustion processes. In this study the data from NO2 strongly correlate with ultrafine particle and black carbon concentrations and for this reason all three species are clearly influenced by road traffic. However, this effect is not so pronounced for the particle mass concentrations, which are additionally influenced by the varying local background concentrations. During the measurements, the averaged concentration for PM10 was on a moderate level at 20.6 µg/m³ (PM2.5 13.4 µg/m³, PM1 10.7 µg/m³). The averaged NO2 concentration was 54.2 µg/m³ during the measurement period, which is above the yearly limit value of 40 µg/m³. However, the hourly limit value of 200 µg/m³ was not exceeded during the measurement period of this study. The averaged particle number concentration (PNC5-250 nm) and black carbon concentration were on a low level compared with values from other studies at roadsides. The PNC5-250 nm was at 6,400 \#/cm³ and for black carbon at 1.8 µg/m³. The lower values for PNC and BC are possibly explained as a result due to the measures from the clean air plan. The measurements of this study took place in summertime. The air pollution concentrations might be higher during colder times of the year due to domestic fuel burning. After all it can be stated, that the additional monitoring of ultrafine particles and black carbon is relevant and important to characterize the composition of the air quality at roadsides and offer a better understanding for the temporal resolution of air pollutants in cities. Moreover, estimations on the risk of air pollution for the human health can more precisely be specified.}, language = {en} } @article{WeberHewelingFischeretal.2017, author = {Weber, Konradin and Heweling, Georg and Fischer, Christian and Lange, Martin}, title = {The use of an octocopter UAV for the determination of air pollutants - a case study of the traffic induced pollution plume around a river bridge in Duesseldorf, Germany}, series = {International Journal of Environmental Science}, volume = {2}, journal = {International Journal of Environmental Science}, issn = {2367-8941}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50805}, pages = {63 -- 66}, year = {2017}, abstract = {Emissions of air pollutants from the road traffic are still a major problem in Germany. It is well known that traffic induced fine particulate matter (PM10, PM2.5, PM1), ultrafine particles (UFPs) and gaseous air pollutants, like e.g. NOx, are adverse to human health. Therefore it is important to monitor these air pollutants in the cities. In this study an octocopter UAV is used as a carrier for measurement systems for UFPs, fine particulate matter and soot. This instrumented octocopter was used for studying the vertical and horizontal variation of the air pollution plume, which originated from the traffic on a river bridge, connecting two parts of Duesseldorf in Germany. This octocopter UAV had been especially designed and built at the Duesseldorf University of Applied Sciences for measurements of air pollutants. It was featuring eight 900 W electric propeller drives and was equipped with a pixhawk flight control. Its lift off weight was about 10.5 kg. About 60 measurement flights were performed by the instrumented octocopter throughout this study. These measurement flights could clearly determine the traffic induced air pollution plume originating from the bridge. Moreover, the dispersion of UFPs within the pollution plume could be monitored with the octocopter flights.}, subject = {Flugk{\"o}rper}, 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} } @inproceedings{PieriDiazBlandetal.2014, author = {Pieri, D. C. and Diaz, J. A. and Bland, G. and Fladeland, M. M. and Abtahi, A. and Alan, A. Jr. and Alegria, O. and Azofeifa, S. and Berthold, R. and Corrales, E. and Fuerstenau, S. and Gerardi, J. and Herlth, D. and Hickman, G. and Hunter, G. and Linick, J. and Mardigal, Y. and Makel, D. and Miles, T. and Realmuto, V. J. and Storms, B. and Vogel, A. and Kolyer, R. and Weber, Konradin}, title = {Systematic observations of Volc{\´a}n Turrialba, Costa Rica, with small unmanned aircraft and aerostats (UAVs): the Costa Rican Airborne Research and Technology Applications (CARTA) missions [Abstract]}, series = {American Geophysical Union, Fall Meeting 2014}, booktitle = {American Geophysical Union, Fall Meeting 2014}, year = {2014}, abstract = {For several years, the University of Costa Rica, NASA Centers (e.g., JPL, ARC, GSFC/WFF, GRC) \& NASA contractors-partners have made regular in situ measurements of aerosols \& gases at Turrialba Volcano in Costa Rica, with aerostats (e.g., tethered balloons \& kites), \& free-flying fixed wing UAVs (e.g., Dragon Eye, Vector Wing 100, DELTA 150), at altitudes up to 12.5Kft ASL within 5km of the summit. Onboard instruments included gas detectors (e.g., SO2, CO2), visible \& thermal IR cameras, air samplers, temperature pressure \& humidity sensors, particle counters, \& a nephelometer. Deployments are timed to support bimonthly overflights of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) onboard the NASA Terra satellite (26 deployments to date). In situ observations of dilute plume SO2 concentrations (~1-20ppmv), plume dimensions, and associated temperature, pressure, \& humidity profiles, validate detailed radiative transfer-based SO2 retrievals, as well as archive-wide ASTER band-ratio SO2 algorithms. Our recent UAV-based CO2 observations confirm high concentrations (e.g., ~3000ppmv max at summit jet), with 1000-1500ppmv flank values, and essentially global background CO2 levels (400ppmv) over distal surroundings. Transient Turrialba He detections (up to 20ppmv) were obtained with a small (~10kg) airborne mass spectrometer on a light aircraft—a UAV version (~3kg) will deploy there soon on the UCR DELTA 500. Thus, these platforms, though small (most payloads <500gm), can perform valuable systematic measurements of potential eruption hazards, as well as of volcano processes. Because they are economical, flexible, and effective, such platforms promise unprecedented capabilities for researchers and responders throughout Central and South America, undertaking volcanic data acquisitions uniquely suited to such small aircraft in close proximity to known hazards, or that were previously only available using full-sized manned aircraft. This work was carried out, in part, at the Jet Propulsion Laboratory of the California Institute of Technology under NASA contract. We are grateful to the Universidad de Costa Rica, the NASA Airborne Science and Earth Surface \& Interior Programs, the Direcci{\´o}n General de Aeron{\´a}utica Civil de Costa Rica, and FH D{\"u}sseldorf for their support.}, subject = {Vulkanismus}, language = {en} } @inproceedings{StaehlerWeyersHoffmannetal.2025, author = {St{\"a}hler, Lisa and Weyers, Simone and Hoffmann, Barbara and Soppa, Vanessa and Oberwinster, Lukas and Weber, Konradin and Pohl, Tobias and Kuß, Oliver and Lang, Alexander and Pischke, Claudia}, title = {UNITY: Multistrategische Intervention zur F{\"o}rderung von Radmobilit{\"a}t, Gesundheit und Nachhaltigkeit im Rahmen der Stadtentwicklung D{\"u}sseldorf [Vortragsabstract]}, series = {60. Jahrestagung der Deutschen Gesellschaft f{\"u}r Sozialmedizin und Pr{\"a}vention (DGSMP) Teilhabe und Ko-Kreation, 17. - 19. September 2025, Berlin}, booktitle = {60. Jahrestagung der Deutschen Gesellschaft f{\"u}r Sozialmedizin und Pr{\"a}vention (DGSMP) Teilhabe und Ko-Kreation, 17. - 19. September 2025, Berlin}, year = {2025}, subject = {Stadtplanung}, language = {de} } @inproceedings{GonzalezRialDinardoPadillaetal.2024, author = {Gonz{\´a}lez Rial, Gabriel and Dinardo, Daniel and Padilla, Germ{\´a}n D. and Barrancos, Jos{\´e} and Hern{\´a}ndez, Pedro A. and P{\´e}rez, Nemesio M. and Weber, Konradin and Fischer, Christian and Amend, Detlef}, title = {Remake of the low cost carbon dioxide sensor of the carbon dioxide network deployed by INVOLCAN in the urban areas of Puerto Naos and La Bombilla, La Palma, Canary Islands}, series = {European Geosciences Union General Assembly 2024, Vienna, Austria, 14-19 Apr 2024}, booktitle = {European Geosciences Union General Assembly 2024, Vienna, Austria, 14-19 Apr 2024}, number = {EGU24-19641}, publisher = {Copernicus}, doi = {10.5194/egusphere-egu24-19641}, year = {2024}, abstract = {An anomalous CO2 degassing appeared by the end of Tajogaite eruption (North-West flank of Cumbre Vieja volcano ridge, La Palma, Canary Islands), in the neighborhoods of La Bombilla and Puerto Naos at about 6 km distance from the volcanic vent. The areas affected by the anomalous CO2 degassing were not directly affected by lava flows during the eruptive period. After the eruption, and due to this strong volcanic-hydrothermal carbon dioxide emissions (CO2 5-20\%) were included in the exclusion zone. CO2 is an invisible toxic gas, as well as asphyxiating, and may be lethal when is present in concentrations higher than 14\%. During the post-eruptive period, INVOLCAN deployed its own indoor and outdoor CO2 monitoring networks in collaboration with other institutions, with the aim of delimitating the anomalous CO2 degassing areas, paying attention to those areas where CO2 air concentration exceeds hazardous thresholds. The number of monitoring stations were increasing to cover most of the homes, garages, basements, and local businesses. The first monitoring network were based on a LILYGO; TTGO T-SIM7000G electroniccard, previously programmed with an unstable algorithm that caused problems during the measurements. After some implementations to enhance the stability of the sensor, a new algorithm was developed that consists of the acquisition of ambient values every 5 seconds, applying a Moving Average Filter in every measurement to avoid outliers. The SIM card integrated in the hardware allows the data transmission to an MQTT broker where the values are published every 5 minutes, recollecting them in a unique Raspberry Pi 4 Model B located at the INVOLCAN headquarters, that reads and stores the data in two databases (InfluxDB and Google Sheets). The visualization of the values are done through Grafana Cloud, recollecting the data from InfluxDB and showing them distributed as tables and a geographic map that illustrates the concentration in the measurement points. The difference between this and the last storing is the flexibility when visualizing the data, that can be transformed to different kind of plots as mentioned. Moreover, an API for the management of each subsystem is created using PyQT, allowing to the user the calibration of the sensors in remote, as well as executing a soft reboot, or the integration of deeper parameters like the sensor mode (manual polling, streaming or command mode) or pressure data. Two of the 20 devices have been successfully installed and they are working correctly in La Palma, meanwhile an amount of 18 devices are being tested and recollecting properly with better stability in CO2 concentration measurements at our laboratory and will be installed indoor in different locations soon. The remaking of the algorithm allows to forget previous problems of wrong data and disconnections, obtaining accurate data compared to commercial sensors and helping the operator to configure and control the sensors without moving to conflicting locations.}, subject = {Vortrag}, language = {en} } @article{WeberFischerPohletal.2015, author = {Weber, Konradin and Fischer, Christian and Pohl, Tobias and B{\"o}hlke, Christoph and Lange, Martin and Scharifi, Emad and Eliasson, Jonas and Yoshitani, Junichi}, title = {The Application of Light Research Aircraft for the Investigation of Volcano Eruption Plumes, Industrial Emissions and Urban Plumes}, series = {WSEAS Transactions on Environment and Development}, volume = {11}, journal = {WSEAS Transactions on Environment and Development}, publisher = {WSEAS}, issn = {2224-3496}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50892}, pages = {89 -- 94}, year = {2015}, abstract = {Airborne measurements have proved to be an important tool for the investigation of volcanic emission plumes, industrial pollution plumes, fugitive emissions and urban pollution plumes. In this paper several examples are demonstrated, how these investigations can be performed by light and microlight propeller aircraft. Throughout the last years innovative aircraft were developed in the light and microlight class showing an excellent flight performance. This enables airborne measurements, which were performed in former years normally by big jet engine driven research aircraft. Moreover, these light and microlight aircraft are equipped with piston motors, which are sturdy enough to operate even in adverse and harsh flight conditions, e.g. in volcanic plumes with high ash concentration. Additionally, turbo charged versions of these airborne piston motors are available, which allow flight altitudes of 7000m - 9000m enabling a large variety of research missions. Another advantage of light and microlight research aircraft is that they are quite cost effective and have a comparatively short certification process for the installation of new measurement equipment. This made it possible to respond fast to the eruption of the Icelandic volcano Eyjafjallaj{\"o}kull 2010 and Grimsv{\"o}tn 2011 with research flights in volcanic ash plumes over Germany and Iceland. In this way it was possible to deliver real airborne measurements additional to the ash plume model calculations of the London Volcanic Ash Advisory Center (VAAC). In this paper examples of airborne measurements in the volcanic plumes of the recent eruptions of Icelandic volcanoes are given. Moreover examples are presented, which highlight the outstanding capabilities of these aircraft for pinpointing industrial emissions and for characterizing urban pollution plumes.}, subject = {Vulkanismus}, language = {en} } @article{PohlFischerHewelingetal.2017, author = {Pohl, Tobias and Fischer, Christian and Heweling, Georg and B{\"o}hlke, Christoph and Weber, Konradin}, title = {A Comparative Study as a Quality Assurance of Stationary and Portable Hand-Held Ultrafine Particle Monitors}, series = {WSEAS Transactions on Environment and Development}, volume = {13}, journal = {WSEAS Transactions on Environment and Development}, publisher = {WSEAS}, issn = {2224-3496}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50799}, pages = {6}, year = {2017}, abstract = {In this study we investigated the performance of two portable hand-held measurement devices (Testo DiSCMini, Grimm NanoCheck) under real environmental conditions at an area on the new campus of the University of Applied Sciences Duesseldorf, which was influenced by construction activities and traffic. The values were compared to the data from a freshly calibrated SMPS (Grimm SMPS+C) as a reference system. The SMPS measured the particle number concentration as well as the particle number size distribution in a range from 5 nm to 350 nm. This was done as a quality assurance for the use of these portable devices for other measurement campaigns for detecting the particle number concentration in mobile applications by e.g. unmanned aerial systems, bicycles, or small aircraft. The results show a good correlation between all the systems. The agreement between the reference system and the NanoCheck was really good, but lower between the DiSCMini and the reference system. Due to the good correlation the data could be post processed with a correction function to reduce the deviation. Finally, it can be stated, that both systems work well under environmental conditions and are well suited for the mobile use for the investigation of ultrafine particle concentration.}, subject = {Messtechnik}, language = {en} }