@article{PrataDezitterDaviesetal.2016, author = {Prata, A. J. and Dezitter, F. and Davies, I. and Weber, Konradin and Birnfeld, M. and Moriano, D. and Bernardo, C. and Vogel, A. and Prata, G. S. and Mather, T. A. and Thomas, H. E. and Cammas, J. and Weber, M.}, title = {Artificial cloud test confirms volcanic ash detection using infrared spectral imaging}, series = {Scientific reports}, volume = {6}, journal = {Scientific reports}, publisher = {Springer Nature}, doi = {10.1038/srep25620}, year = {2016}, abstract = {Airborne volcanic ash particles are a known hazard to aviation. Currently, there are no means available to detect ash in flight as the particles are too fine (radii < 30 μm) for on-board radar detection and, even in good visibility, ash clouds are difficult or impossible to detect by eye. The economic cost and societal impact of the April/May 2010 Icelandic eruption of Eyjafjallaj{\"o}kull generated renewed interest in finding ways to identify airborne volcanic ash in order to keep airspace open and avoid aircraft groundings. We have designed and built a bi-spectral, fast-sampling, uncooled infrared camera device (AVOID) to examine its ability to detect volcanic ash from commercial jet aircraft at distances of more than 50 km ahead. Here we report results of an experiment conducted over the Atlantic Ocean, off the coast of France, confirming the ability of the device to detect and quantify volcanic ash in an artificial ash cloud created by dispersal of volcanic ash from a second aircraft. A third aircraft was used to measure the ash in situ using optical particle counters. The cloud was composed of very fine ash (mean radii ~10 μm) collected from Iceland immediately after the Eyjafjallaj{\"o}kull eruption and had a vertical thickness of ~200 m, a width of ~2 km and length of between 2 and 12 km. Concentrations of ~200 μg m(-3) were identified by AVOID at distances from ~20 km to ~70 km. For the first time, airborne remote detection of volcanic ash has been successfully demonstrated from a long-range flight test aircraft.}, language = {en} } @article{BonnvonSchneidemesserAndrichetal.2016, author = {Bonn, Boris and von Schneidemesser, Erika and Andrich, Dorota and Quedenau, J{\"o}rn and Gerwig, Holger and L{\"u}decke, Anja and Kura, J{\"u}rgen and Pietsch, Axel and Ehlers, Christian and Klemp, Dieter and Kofahl, Claudia and Nothard, Rainer and Kerschbaumer, Andreas and Junkermann, Wolfgang and Grote, R{\"u}diger and Pohl, Tobias and Weber, Konradin and Lode, Birgit and Sch{\"o}nberger, Philipp and Churkina, Galina and Butler, Tim M. and Lawrence, Mark G.}, title = {BAERLIN2014 - the influence of land surface types on and the horizontal heterogeneity of air pollutant levels in Berlin}, series = {Atmospheric Chemistry and Physics}, volume = {16}, journal = {Atmospheric Chemistry and Physics}, number = {12}, publisher = {Copernicus}, issn = {1680-7324}, doi = {10.5194/acp-16-7785-2016}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-50065}, pages = {7785 -- 7811}, year = {2016}, abstract = {Abstract. Urban air quality and human health are among the key aspects of future urban planning. In order to address pollutants such as ozone and particulate matter, efforts need to be made to quantify and reduce their concentrations. One important aspect in understanding urban air quality is the influence of urban vegetation which may act as both emitter and sink for trace gases and aerosol particles. In this context, the "Berlin Air quality and Ecosystem Research: Local and long-range Impact of anthropogenic and Natural hydrocarbons 2014" (BAERLIN2014) campaign was conducted between 2 June and 29 August in the metropolitan area of Berlin and Brandenburg, Germany. The predominant goals of the campaign were (1) the characterization of urban gaseous and particulate pollution and its attribution to anthropogenic and natural sources in the region of interest, especially considering the connection between biogenic volatile organic compounds and particulates and ozone; (2) the quantification of the impact of urban vegetation on organic trace gas levels and the presence of oxidants such as ozone; and (3) to explain the local heterogeneity of pollutants by defining the distribution of sources and sinks relevant for the interpretation of model simulations. In order to do so, the campaign included stationary measurements at urban background station and mobile observations carried out from bicycle, van and airborne platforms. This paper provides an overview of the mobile measurements (Mobile BAERLIN2014) and general conclusions drawn from the analysis. Bicycle measurements showed micro-scale variations of temperature and particulate matter, displaying a substantial reduction of mean temperatures and particulate levels in the proximity of vegetated areas compared to typical urban residential area (background) measurements. Van measurements extended the area covered by bicycle observations and included continuous measurements of O3, NOx, CO, CO2 and point-wise measurement of volatile organic compounds (VOCs) at representative sites for traffic- and vegetation-affected sites. The quantification displayed notable horizontal heterogeneity of the short-lived gases and particle number concentrations. For example, baseline concentrations of the traffic-related chemical species CO and NO varied on average by up to ±22.2 and ±63.5 \%, respectively, on the scale of 100 m around any measurement location. Airborne observations revealed the dominant source of elevated urban particulate number and mass concentrations being local, i.e., not being caused by long-range transport. Surface-based observations related these two parameters predominantly to traffic sources. Vegetated areas lowered the pollutant concentrations substantially with ozone being reduced most by coniferous forests, which is most likely caused by their reactive biogenic VOC emissions. With respect to the overall potential to reduce air pollutant levels, forests were found to result in the largest decrease, followed by parks and facilities for sports and leisure. Surface temperature was generally 0.6-2.1 °C lower in vegetated regions, which in turn will have an impact on tropospheric chemical processes. Based on our findings, effective future mitigation activities to provide a more sustainable and healthier urban environment should focus predominantly on reducing fossil-fuel emissions from traffic as well as on increasing vegetated areas.}, language = {en} } @incollection{EliassonWatsonWeber2016, author = {Eliasson, J. and Watson, I.M. and Weber, Konradin}, title = {In Situ Observations of Airborne Ash From Manned Aircraft}, series = {Volcanic Ash}, booktitle = {Volcanic Ash}, publisher = {Elsevier}, isbn = {9780081004050}, doi = {10.1016/B978-0-08-100405-0.00009-4}, pages = {89 -- 98}, year = {2016}, language = {en} }