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1. Aerosol absorption profiling from the synergy of lidar and sun-photometry: the ACTRIS-2 campaigns in Germany, Greece and Cyprus

Author

Tsekeri Alexandra, Amiridis Vassilis, Lopatin Anton, Marinou Eleni, Giannakaki Eleni, Pikridas Michael, Sciare Jean, Liakakou Eleni, Gerasopoulos Evangelos, Duesing Sebastian, Corbin Joel C., Gysel Martin, Bukowiecki Nicolas, Baars Holger, Engelmann Ronny, Wehner Birgit, Kottas Michael, Mamali Dimitra, Kokkalis Panagiotis, Raptis Panagiotis I., Stavroulas Iasonas, Keleshis Christos, Müller Detlef, Solomos Stavros, Binietoglou Ioannis, Mihalopoulos Nikolaos, Papayannis Alexandros, Stachlewska Iwona S., Igloffstein Julia, Wandinger Ulla, Ansmann Albert, Dubovik Oleg, and Goloub Philippe

Subjects
Physics, QC1-999
Abstract

Aerosol absorption profiling is crucial for radiative transfer calculations and climate modelling. Here, we utilize the synergy of lidar with sun-photometer measurements to derive the absorption coefficient and single scattering albedo profiles during the ACTRIS-2 campaigns held in Germany, Greece and Cyprus. The remote sensing techniques are compared with in situ measurements in order to harmonize and validate the different methodologies and reduce the absorption profiling uncertainties.

Published
2018
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2. The role of low-volatility organic compounds in initial particle growth in the atmosphere

Author

Tröstl, Jasmin, Chuang, Wayne K, Gordon, Hamish, Heinritzi, Martin, Yan, Chao, Molteni, Ugo, Ahlm, Lars, Frege, Carla, Bianchi, Federico, Wagner, Robert, Simon, Mario, Lehtipalo, Katrianne, Williamson, Christina, Craven, Jill S, Duplissy, Jonathan, Adamov, Alexey, Almeida, Joao, Bernhammer, Anne-Kathrin, Breitenlechner, Martin, Brilke, Sophia, Dias, Antònio, Ehrhart, Sebastian, Flagan, Richard C, Franchin, Alessandro, Fuchs, Claudia, Guida, Roberto, Gysel, Martin, Hansel, Armin, Hoyle, Christopher R, Jokinen, Tuija, Junninen, Heikki, Kangasluoma, Juha, Keskinen, Helmi, Kim, Jaeseok, Krapf, Manuel, Kürten, Andreas, Laaksonen, Ari, Lawler, Michael, Leiminger, Markus, Mathot, Serge, Möhler, Ottmar, Nieminen, Tuomo, Onnela, Antti, Petäjä, Tuukka, Piel, Felix M, Miettinen, Pasi, Rissanen, Matti P, Rondo, Linda, Sarnela, Nina, Schobesberger, Siegfried, Sengupta, Kamalika, Sipilä, Mikko, Smith, James N, Steiner, Gerhard, Tomè, Antònio, Virtanen, Annele, Wagner, Andrea C, Weingartner, Ernest, Wimmer, Daniela, Winkler, Paul M, Ye, Penglin, Carslaw, Kenneth S, Curtius, Joachim, Dommen, Josef, Kirkby, Jasper, Kulmala, Markku, Riipinen, Ilona, Worsnop, Douglas R, Donahue, Neil M, and Baltensperger, Urs

Subjects
General Science & Technology
Abstract

About half of present-day cloud condensation nuclei originate from atmospheric nucleation, frequently appearing as a burst of new particles near midday. Atmospheric observations show that the growth rate of new particles often accelerates when the diameter of the particles is between one and ten nanometres. In this critical size range, new particles are most likely to be lost by coagulation with pre-existing particles, thereby failing to form new cloud condensation nuclei that are typically 50 to 100 nanometres across. Sulfuric acid vapour is often involved in nucleation but is too scarce to explain most subsequent growth, leaving organic vapours as the most plausible alternative, at least in the planetary boundary layer. Although recent studies predict that low-volatility organic vapours contribute during initial growth, direct evidence has been lacking. The accelerating growth may result from increased photolytic production of condensable organic species in the afternoon, and the presence of a possible Kelvin (curvature) effect, which inhibits organic vapour condensation on the smallest particles (the nano-Köhler theory), has so far remained ambiguous. Here we present experiments performed in a large chamber under atmospheric conditions that investigate the role of organic vapours in the initial growth of nucleated organic particles in the absence of inorganic acids and bases such as sulfuric acid or ammonia and amines, respectively. Using data from the same set of experiments, it has been shown that organic vapours alone can drive nucleation. We focus on the growth of nucleated particles and find that the organic vapours that drive initial growth have extremely low volatilities (saturation concentration less than 10(-4.5) micrograms per cubic metre). As the particles increase in size and the Kelvin barrier falls, subsequent growth is primarily due to more abundant organic vapours of slightly higher volatility (saturation concentrations of 10(-4.5) to 10(-0.5) micrograms per cubic metre). We present a particle growth model that quantitatively reproduces our measurements. Furthermore, we implement a parameterization of the first steps of growth in a global aerosol model and find that concentrations of atmospheric cloud concentration nuclei can change substantially in response, that is, by up to 50 per cent in comparison with previously assumed growth rate parameterizations.

Published
2016

5. Corrigendum: Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition

Author

Schmale, Julia, Henning, Silvia, Henzing, Bas, Keskinen, Helmi, Sellegri, Karine, Ovadnevaite, Jurgita, Bougiatioti, Aikaterini, Kalivitis, Nikos, Stavroulas, Iasonas, Jefferson, Anne, Park, Minsu, Schlag, Patrick, Kristensson, Adam, Iwamoto, Yoko, Pringle, Kirsty, Reddington, Carly, Aalto, Pasi, Äijälä, Mikko, Baltensperger, Urs, Bialek, Jakub, Birmili, Wolfram, Bukowiecki, Nicolas, Ehn, Mikael, Fjæraa, Ann Mari, Fiebig, Markus, Frank, Göran, Fröhlich, Roman, Frumau, Arnoud, Furuya, Masaki, Hammer, Emanuel, Heikkinen, Liine, Herrmann, Erik, Holzinger, Rupert, Hyono, Hiroyuki, Kanakidou, Maria, Kiendler-Scharr, Astrid, Kinouchi, Kento, Kos, Gerard, Kulmala, Markku, Mihalopoulos, Nikolaos, Motos, Ghislain, Nenes, Athanasios, O'Dowd, Colin, Paramonov, Mikhail, Petäjä, Tuukka, Picard, David, Poulain, Laurent, Prévôt, André Stephan Henry, Slowik, Jay, Sonntag, Andre, Swietlicki, Erik, Svenningsson, Birgitta, Tsurumaru, Hiroshi, Wiedensohler, Alfred, Wittbom, Cerina, Ogren, John A., Matsuki, Atsushi, Yum, Seong Soo, Myhre, Cathrine Lund, Carslaw, Ken, Stratmann, Frank, Gysel, Martin, Sub Atmospheric physics and chemistry, and Marine and Atmospheric Research

Subjects
Statistics and Probability, Statistics, Probability and Uncertainty, Library and Information Sciences, Information Systems, Education, Computer Science Applications
Abstract

This corrects the article DOI: 10.1038/sdata.2017.3.

Published
2018

6. AEROSOL ABSORPTION PROFILING FROM THE SYNERGY OF LIDAR AND SUN-PHOTOMETRY: THE ACTRIS-2 CAMPAIGNS IN GERMANY, GREECE AND CYPRUS

Author

Tsekeri, Alexandra Amiridis, Vassilis Lopatin, Anton and Marinou, Eleni Giannakaki, Eleni Pikridas, Michael Sciare, Jean Liakakou, Eleni Gerasopoulos, Evangelos Duesing, Sebastian Corbin, Joel C. Gysel, Martin Bukowiecki, Nicolas and Baars, Holger Engelmann, Ronny Wehner, Birgit Kottas, Michael Mamali, Dimitra Kokkalis, Panagiotis Raptis, I, Panagiotis Stavroulas, Iasonas Keleshis, Christos Muller, Detlef Solomos, Stavros Binietoglou, Ioannis Mihalopoulos, Nikolaos Papayannis, Alexandros Stachlewska, Iwona S. and Igloffstein, Julia Wandinger, Ulla Ansmann, Albert Dubovik, Oleg Goloub, Philippe

Abstract

Aerosol absorption profiling is crucial for radiative transfer calculations and climate modelling. Here, we utilize the synergy of lidar with sun-photometer measurements to derive the absorption coefficient and single scattering albedo profiles during the ACTRIS-2 campaigns held in Germany, Greece and Cyprus. The remote sensing techniques are compared with in situ measurements in order to harmonize and validate the different methodologies and reduce the absorption profiling uncertainties.

Published
2018

7. Production of particulate brown carbon during atmospheric aging of residential wood-burning emissions

Author

Kumar, Nivedita K., primary, Corbin, Joel C., additional, Bruns, Emily A., additional, Massabó, Dario, additional, Slowik, Jay G., additional, Drinovec, Luka, additional, Močnik, Griša, additional, Prati, Paolo, additional, Vlachou, Athanasia, additional, Baltensperger, Urs, additional, Gysel, Martin, additional, El-Haddad, Imad, additional, and Prévôt, André S. H., additional

Published
2018
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10. Effects of mixing state on optical and radiative properties of black carbon in the European Arctic

Author

Zanatta, Marco, primary, Laj, Paolo, additional, Gysel, Martin, additional, Baltensperger, Urs, additional, Vratolis, Stergios, additional, Eleftheriadis, Konstantinos, additional, Kondo, Yutaka, additional, Dubuisson, Philippe, additional, Winiarek, Victor, additional, Kazadzis, Stelios, additional, Tunved, Peter, additional, and Jacobi, Hans-Werner, additional

Published
2018
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11. Data Descriptor: Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition

Author

Schmale, Julia, Henning, Silvia, Henzing, Bas, Keskinen, Helmi, Sellegri, Karine, Ovadnevaite, Jurgita, Bougiatioti, Aikaterini, Kalivitis, Nikos, Stavroulas, Iasonas, Jefferson, Anne, Park, Minsu, Schlag, Patrick, Kristensson, Adam, Iwamoto, Yoko, Pringle, Kirsty, Reddington, Carly, Aalto, Pasi, Äijälä, Mikko, Baltensperger, Urs, Bialek, Jakub, Birmili, Wolfram, Bukowiecki, Nicolas, Ehn, Mikael, Fjæraa, Ann Mari, Fiebig, Markus, Frank, Göran, Fröhlich, Roman, Frumau, Arnoud, Furuya, Masaki, Hammer, Emanuel, Heikkinen, Liine, Herrmann, Erik, Holzinger, Rupert, Hyono, Hiroyuki, Kanakidou, Maria, Kiendler-Scharr, Astrid, Kinouchi, Kento, Kos, Gerard P A, Kulmala, Markku, Mihalopoulos, Nikolaos, Motos, Ghislain, Nenes, Athanasios, O'Dowd, Colin, Paramonov, Mikhail, Petäjä, Tuukka, Picard, David, Poulain, Laurent, Prévôt, André Stephan Henry, Slowik, Jay, Sonntag, Andre, Swietlicki, Erik, Svenningsson, Birgitta, Tsurumaru, Hiroshi, Wiedensohler, Alfred, Wittbom, Cerina, Ogren, John A., Matsuki, Atsushi, Yum, Seong Soo, Myhre, Cathrine Lund, Carslaw, Ken, Stratmann, Frank, Gysel, Martin, Sub Atmospheric physics and chemistry, and Marine and Atmospheric Research

Subjects
Statistics and Probability, Statistics, Probability and Uncertainty, Library and Information Sciences, Information Systems, Education, Computer Science Applications
Abstract

Cloud condensation nuclei (CCN) number concentrations alongside with submicrometer particle number size distributions and particle chemical composition have been measured at atmospheric observatories of the Aerosols, Clouds, and Trace gases Research InfraStructure (ACTRIS) as well as other international sites over multiple years. Here, harmonized data records from 11 observatories are summarized, spanning 98,677 instrument hours for CCN data, 157,880 for particle number size distributions, and 70,817 for chemical composition data. The observatories represent nine different environments, e.g., Arctic, Atlantic, Pacific and Mediterranean maritime, boreal forest, or high alpine atmospheric conditions. This is a unique collection of aerosol particle properties most relevant for studying aerosol-cloud interactions which constitute the largest uncertainty in anthropogenic radiative forcing of the climate. The dataset is appropriate for comprehensive aerosol characterization (e.g., closure studies of CCN), model-measurement intercomparison and satellite retrieval method evaluation, among others. Data have been acquired and processed following international recommendations for quality assurance and have undergone multiple stages of quality assessment.

Published
2017

15. A European aerosol phenomenology – 6: scattering properties of atmospheric aerosol particles from 28 ACTRIS sites

Author

Pandolfi, Marco, primary, Alados-Arboledas, Lucas, additional, Alastuey, Andrés, additional, Andrade, Marcos, additional, Angelov, Christo, additional, Artiñano, Begoña, additional, Backman, John, additional, Baltensperger, Urs, additional, Bonasoni, Paolo, additional, Bukowiecki, Nicolas, additional, Collaud Coen, Martine, additional, Conil, Sébastien, additional, Coz, Esther, additional, Crenn, Vincent, additional, Dudoitis, Vadimas, additional, Ealo, Marina, additional, Eleftheriadis, Kostas, additional, Favez, Olivier, additional, Fetfatzis, Prodromos, additional, Fiebig, Markus, additional, Flentje, Harald, additional, Ginot, Patrick, additional, Gysel, Martin, additional, Henzing, Bas, additional, Hoffer, Andras, additional, Holubova Smejkalova, Adela, additional, Kalapov, Ivo, additional, Kalivitis, Nikos, additional, Kouvarakis, Giorgos, additional, Kristensson, Adam, additional, Kulmala, Markku, additional, Lihavainen, Heikki, additional, Lunder, Chris, additional, Luoma, Krista, additional, Lyamani, Hassan, additional, Marinoni, Angela, additional, Mihalopoulos, Nikos, additional, Moerman, Marcel, additional, Nicolas, José, additional, O'Dowd, Colin, additional, Petäjä, Tuukka, additional, Petit, Jean-Eudes, additional, Pichon, Jean Marc, additional, Prokopciuk, Nina, additional, Putaud, Jean-Philippe, additional, Rodríguez, Sergio, additional, Sciare, Jean, additional, Sellegri, Karine, additional, Swietlicki, Erik, additional, Titos, Gloria, additional, Tuch, Thomas, additional, Tunved, Peter, additional, Ulevicius, Vidmantas, additional, Vaishya, Aditya, additional, Vana, Milan, additional, Virkkula, Aki, additional, Vratolis, Stergios, additional, Weingartner, Ernest, additional, Wiedensohler, Alfred, additional, and Laj, Paolo, additional

Published
2018
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16. Supplementary material to "Effects of mixing state on optical and radiative properties of black carbon in the European Arctic"

Author

Zanatta, Marco, primary, Laj, Paolo, additional, Gysel, Martin, additional, Baltensperger, Urs, additional, Vratolis, Stergios, additional, Eleftheriadis, Kostas, additional, Kondo, Yutaka, additional, Dubuisson, Philippe, additional, Winiarek, Victor, additional, Kazadzis, Stelios, additional, Tunved, Peter, additional, and Jacobi, Hans-Werner, additional

Published
2018
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17. Correction: Corrigendum: Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition

Author

Schmale, Julia, primary, Henning, Silvia, additional, Henzing, Bas, additional, Keskinen, Helmi, additional, Sellegri, Karine, additional, Ovadnevaite, Jurgita, additional, Bougiatioti, Aikaterini, additional, Kalivitis, Nikos, additional, Stavroulas, Iasonas, additional, Jefferson, Anne, additional, Park, Minsu, additional, Schlag, Patrick, additional, Kristensson, Adam, additional, Iwamoto, Yoko, additional, Pringle, Kirsty, additional, Reddington, Carly, additional, Aalto, Pasi, additional, Äijälä, Mikko, additional, Baltensperger, Urs, additional, Bialek, Jakub, additional, Birmili, Wolfram, additional, Bukowiecki, Nicolas, additional, Ehn, Mikael, additional, Fjæraa, Ann Mari, additional, Fiebig, Markus, additional, Frank, Göran, additional, Fröhlich, Roman, additional, Frumau, Arnoud, additional, Furuya, Masaki, additional, Hammer, Emanuel, additional, Heikkinen, Liine, additional, Herrmann, Erik, additional, Holzinger, Rupert, additional, Hyono, Hiroyuki, additional, Kanakidou, Maria, additional, Kiendler-Scharr, Astrid, additional, Kinouchi, Kento, additional, Kos, Gerard, additional, Kulmala, Markku, additional, Mihalopoulos, Nikolaos, additional, Motos, Ghislain, additional, Nenes, Athanasios, additional, O’Dowd, Colin, additional, Paramonov, Mikhail, additional, Petäjä, Tuukka, additional, Picard, David, additional, Poulain, Laurent, additional, Prévôt, André Stephan Henry, additional, Slowik, Jay, additional, Sonntag, Andre, additional, Swietlicki, Erik, additional, Svenningsson, Birgitta, additional, Tsurumaru, Hiroshi, additional, Wiedensohler, Alfred, additional, Wittbom, Cerina, additional, Ogren, John A., additional, Matsuki, Atsushi, additional, Yum, Seong Soo, additional, Myhre, Cathrine Lund, additional, Carslaw, Ken, additional, Stratmann, Frank, additional, and Gysel, Martin, additional

Published
2018
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18. Production of particulate brown carbon during atmospheric aging of wood-burning emissions

Author

Kumar, Nivedita K., primary, Corbin, Joel C., additional, Bruns, Emily A., additional, Massabó, Dario, additional, Slowik, Jay G., additional, Drinovec, Luka, additional, Močnik, Griša, additional, Prati, Paolo, additional, Vlachou, Athanasia, additional, Baltensperger, Urs, additional, Gysel, Martin, additional, El-Haddad, Imad, additional, and Prévôt, André S. H., additional

Published
2018
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19. Supplementary material to "Production of particulate brown carbon during atmospheric aging of wood-burning emissions"

Author

Kumar, Nivedita K., primary, Corbin, Joel C., additional, Bruns, Emily A., additional, Massabó, Dario, additional, Slowik, Jay G., additional, Drinovec, Luka, additional, Močnik, Griša, additional, Prati, Paolo, additional, Vlachou, Athanasia, additional, Baltensperger, Urs, additional, Gysel, Martin, additional, El-Haddad, Imad, additional, and Prévôt, André S. H., additional

Published
2018
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20. Long-term cloud condensation nuclei number concentration, particle number size distribution and chemical composition measurements at regionally representative observatories

Author

Schmale, Julia, primary, Henning, Silvia, additional, Decesari, Stefano, additional, Henzing, Bas, additional, Keskinen, Helmi, additional, Sellegri, Karine, additional, Ovadnevaite, Jurgita, additional, Pöhlker, Mira L., additional, Brito, Joel, additional, Bougiatioti, Aikaterini, additional, Kristensson, Adam, additional, Kalivitis, Nikos, additional, Stavroulas, Iasonas, additional, Carbone, Samara, additional, Jefferson, Anne, additional, Park, Minsu, additional, Schlag, Patrick, additional, Iwamoto, Yoko, additional, Aalto, Pasi, additional, Äijälä, Mikko, additional, Bukowiecki, Nicolas, additional, Ehn, Mikael, additional, Frank, Göran, additional, Fröhlich, Roman, additional, Frumau, Arnoud, additional, Herrmann, Erik, additional, Herrmann, Hartmut, additional, Holzinger, Rupert, additional, Kos, Gerard, additional, Kulmala, Markku, additional, Mihalopoulos, Nikolaos, additional, Nenes, Athanasios, additional, O'Dowd, Colin, additional, Petäjä, Tuukka, additional, Picard, David, additional, Pöhlker, Christopher, additional, Pöschl, Ulrich, additional, Poulain, Laurent, additional, Prévôt, André Stephan Henry, additional, Swietlicki, Erik, additional, Andreae, Meinrat O., additional, Artaxo, Paulo, additional, Wiedensohler, Alfred, additional, Ogren, John, additional, Matsuki, Atsushi, additional, Yum, Seong Soo, additional, Stratmann, Frank, additional, Baltensperger, Urs, additional, and Gysel, Martin, additional

Published
2018
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21. Supplementary material to "A European aerosol phenomenology-6: Scattering properties of atmospheric aerosol particles from 28 ACTRIS sites"

Author

Pandolfi, Marco, primary, Alados-Arboledas, Lucas, additional, Alastuey, Andrés, additional, Andrade, Marcos, additional, Artiñano, Begoña, additional, Backman, John, additional, Baltensperger, Urs, additional, Bonasoni, Paolo, additional, Bukowiecki, Nicolas, additional, Collaud Coen, Martine, additional, Conil, Sebastian, additional, Coz, Esther, additional, Crenn, Vincent, additional, Dudoitis, Vadimas, additional, Ealo, Marina, additional, Eleftheriadis, Kostas, additional, Favez, Olivier, additional, Fetfatzis, Prodromos, additional, Fiebig, Markus, additional, Flentje, Harald, additional, Ginot, Patrick, additional, Gysel, Martin, additional, Henzing, Bas, additional, Hoffer, Andras, additional, Holubova Smejkalova, Adela, additional, Kalapov, Ivo, additional, Kalivitis, Nikos, additional, Kouvarakis, Giorgos, additional, Kristensson, Adam, additional, Kulmala, Markku, additional, Lihavainen, Heikki, additional, Lunder, Chris, additional, Luoma, Krista, additional, Lyamani, Hassan, additional, Marinoni, Angela, additional, Mihalopoulos, Nikos, additional, Moerman, Marcel, additional, Nicolas, José, additional, O'Dowd, Colin, additional, Petäjä, Tuukka, additional, Petit, Jean-Eudes, additional, Pichon, Jean Marc, additional, Prokopciuk, Nina, additional, Putaud, Jean-Philippe, additional, Rodríguez, Sergio, additional, Sciare, Jean, additional, Sellegri, Karine, additional, Stamenov, Dimiter B., additional, Swietlicki, Erik, additional, Titos, Gloria, additional, Tuch, Thomas, additional, Tunved, Peter, additional, Ulevicius, Vidmantas, additional, Vaishya, Aditya, additional, Vana, Milan, additional, Virkkula, Aki, additional, Vratolis, Stergios, additional, Weingartner, Ernest, additional, Wiedensohler, Alfred, additional, and Laj, Paolo, additional

Published
2017
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22. A European aerosol phenomenology-6: Scattering properties of atmospheric aerosol particles from 28 ACTRIS sites

Author

Pandolfi, Marco, primary, Alados-Arboledas, Lucas, additional, Alastuey, Andrés, additional, Andrade, Marcos, additional, Artiñano, Begoña, additional, Backman, John, additional, Baltensperger, Urs, additional, Bonasoni, Paolo, additional, Bukowiecki, Nicolas, additional, Collaud Coen, Martine, additional, Conil, Sebastian, additional, Coz, Esther, additional, Crenn, Vincent, additional, Dudoitis, Vadimas, additional, Ealo, Marina, additional, Eleftheriadis, Kostas, additional, Favez, Olivier, additional, Fetfatzis, Prodromos, additional, Fiebig, Markus, additional, Flentje, Harald, additional, Ginot, Patrick, additional, Gysel, Martin, additional, Henzing, Bas, additional, Hoffer, Andras, additional, Holubova Smejkalova, Adela, additional, Kalapov, Ivo, additional, Kalivitis, Nikos, additional, Kouvarakis, Giorgos, additional, Kristensson, Adam, additional, Kulmala, Markku, additional, Lihavainen, Heikki, additional, Lunder, Chris, additional, Luoma, Krista, additional, Lyamani, Hassan, additional, Marinoni, Angela, additional, Mihalopoulos, Nikos, additional, Moerman, Marcel, additional, Nicolas, José, additional, O'Dowd, Colin, additional, Petäjä, Tuukka, additional, Petit, Jean-Eudes, additional, Pichon, Jean Marc, additional, Prokopciuk, Nina, additional, Putaud, Jean-Philippe, additional, Rodríguez, Sergio, additional, Sciare, Jean, additional, Sellegri, Karine, additional, Stamenov, Dimiter B., additional, Swietlicki, Erik, additional, Titos, Gloria, additional, Tuch, Thomas, additional, Tunved, Peter, additional, Ulevicius, Vidmantas, additional, Vaishya, Aditya, additional, Vana, Milan, additional, Virkkula, Aki, additional, Vratolis, Stergios, additional, Weingartner, Ernest, additional, Wiedensohler, Alfred, additional, and Laj, Paolo, additional

Published
2017
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23. What do we learn from long-term cloud condensation nuclei number concentration, particle number size distribution, and chemical composition measurements at regionally representative observatories?

Author

Schmale, Julia, primary, Henning, Silvia, additional, Decesari, Stefano, additional, Henzing, Bas, additional, Keskinen, Helmi, additional, Paramonov, Mikhail, additional, Sellegri, Karine, additional, Ovadnevaite, Jurgita, additional, Pöhlker, Mira L., additional, Brito, Joel, additional, Bougiatioti, Aikaterini, additional, Kristensson, Adam, additional, Kalivitis, Nikos, additional, Stavroulas, Iasonas, additional, Carbone, Samara, additional, Jefferson, Anne, additional, Park, Minsu, additional, Schlag, Patrick, additional, Iwamoto, Yoko, additional, Aalto, Pasi, additional, Äijälä, Mikko, additional, Bukowiecki, Nicolas, additional, Ehn, Mikael, additional, Frank, Göran, additional, Fröhlich, Roman, additional, Frumau, Arnoud, additional, Herrmann, Erik, additional, Herrmann, Hartmut, additional, Holzinger, Rupert, additional, Kos, Gerard, additional, Kulmala, Markku, additional, Mihalopoulos, Nikolaos, additional, Nenes, Athanasios, additional, O'Dowd, Colin, additional, Petäjä, Tuukka, additional, Picard, David, additional, Pöhlker, Christopher, additional, Pöschl, Ulrich, additional, Poulain, Laurent, additional, Prévôt, André Stephan Henry, additional, Swietlicki, Erik, additional, Andreae, Meintrat O., additional, Artaxo, Paulo, additional, Wiedensohler, Alfred, additional, Ogren, John, additional, Matsuki, Atsushi, additional, Yum, Seong Soo, additional, Stratmann, Frank, additional, Baltensperger, Urs, additional, and Gysel, Martin, additional

Published
2017
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24. Supplementary material to "What do we learn from long-term cloud condensation nuclei number concentration, particle number size distribution, and chemical composition measurements at regionally representative observatories?"

Author

Schmale, Julia, primary, Henning, Silvia, additional, Decesari, Stefano, additional, Henzing, Bas, additional, Keskinen, Helmi, additional, Paramonov, Mikhail, additional, Sellegri, Karine, additional, Ovadnevaite, Jurgita, additional, Pöhlker, Mira L., additional, Brito, Joel, additional, Bougiatioti, Aikaterini, additional, Kristensson, Adam, additional, Kalivitis, Nikos, additional, Stavroulas, Iasonas, additional, Carbone, Samara, additional, Jefferson, Anne, additional, Park, Minsu, additional, Schlag, Patrick, additional, Iwamoto, Yoko, additional, Aalto, Pasi, additional, Äijälä, Mikko, additional, Bukowiecki, Nicolas, additional, Ehn, Mikael, additional, Frank, Göran, additional, Fröhlich, Roman, additional, Frumau, Arnoud, additional, Herrmann, Erik, additional, Herrmann, Hartmut, additional, Holzinger, Rupert, additional, Kos, Gerard, additional, Kulmala, Markku, additional, Mihalopoulos, Nikolaos, additional, Nenes, Athanasios, additional, O'Dowd, Colin, additional, Petäjä, Tuukka, additional, Picard, David, additional, Pöhlker, Christopher, additional, Pöschl, Ulrich, additional, Poulain, Laurent, additional, Prévôt, André Stephan Henry, additional, Swietlicki, Erik, additional, Andreae, Meintrat O., additional, Artaxo, Paulo, additional, Wiedensohler, Alfred, additional, Ogren, John, additional, Matsuki, Atsushi, additional, Yum, Seong Soo, additional, Stratmann, Frank, additional, Baltensperger, Urs, additional, and Gysel, Martin, additional

Published
2017
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25. Evaluation of the absorption Ångström exponents for traffic and wood burning in the Aethalometer-based source apportionment using radiocarbon measurements of ambient aerosol

Author

Zotter, Peter, primary, Herich, Hanna, additional, Gysel, Martin, additional, El-Haddad, Imad, additional, Zhang, Yanlin, additional, Močnik, Griša, additional, Hüglin, Christoph, additional, Baltensperger, Urs, additional, Szidat, Sönke, additional, and Prévôt, André S. H., additional

Published
2017
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26. Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition

Author

Schmale, Julia, primary, Henning, Silvia, additional, Henzing, Bas, additional, Keskinen, Helmi, additional, Sellegri, Karine, additional, Ovadnevaite, Jurgita, additional, Bougiatioti, Aikaterini, additional, Kalivitis, Nikos, additional, Stavroulas, Iasonas, additional, Jefferson, Anne, additional, Park, Minsu, additional, Schlag, Patrick, additional, Kristensson, Adam, additional, Iwamoto, Yoko, additional, Pringle, Kirsty, additional, Reddington, Carly, additional, Aalto, Pasi, additional, Äijälä, Mikko, additional, Baltensperger, Urs, additional, Bialek, Jakub, additional, Birmili, Wolfram, additional, Bukowiecki, Nicolas, additional, Ehn, Mikael, additional, Fjæraa, Ann Mari, additional, Fiebig, Markus, additional, Frank, Göran, additional, Fröhlich, Roman, additional, Frumau, Arnoud, additional, Furuya, Masaki, additional, Hammer, Emanuel, additional, Heikkinen, Liine, additional, Herrmann, Erik, additional, Holzinger, Rupert, additional, Hyono, Hiroyuki, additional, Kanakidou, Maria, additional, Kiendler-Scharr, Astrid, additional, Kinouchi, Kento, additional, Kos, Gerard, additional, Kulmala, Markku, additional, Mihalopoulos, Nikolaos, additional, Motos, Ghislain, additional, Nenes, Athanasios, additional, O’Dowd, Colin, additional, Paramonov, Mikhail, additional, Petäjä, Tuukka, additional, Picard, David, additional, Poulain, Laurent, additional, Prévôt, André Stephan Henry, additional, Slowik, Jay, additional, Sonntag, Andre, additional, Swietlicki, Erik, additional, Svenningsson, Birgitta, additional, Tsurumaru, Hiroshi, additional, Wiedensohler, Alfred, additional, Wittbom, Cerina, additional, Ogren, John A., additional, Matsuki, Atsushi, additional, Yum, Seong Soo, additional, Myhre, Cathrine Lund, additional, Carslaw, Ken, additional, Stratmann, Frank, additional, and Gysel, Martin, additional

Published
2017
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29. Contribution of new particle formation to the total aerosol concentration at the high‐altitude site Jungfraujoch (3580 m asl, Switzerland)

Author

Tröstl, Jasmin, primary, Herrmann, Erik, additional, Frege, Carla, additional, Bianchi, Federico, additional, Molteni, Ugo, additional, Bukowiecki, Nicolas, additional, Hoyle, Christopher R., additional, Steinbacher, Martin, additional, Weingartner, Ernest, additional, Dommen, Josef, additional, Gysel, Martin, additional, and Baltensperger, Urs, additional

Published
2016
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30. Cloud droplet activation properties and scavenged fraction of black carbon in liquid-phase clouds at the high-alpine research station Jungfraujoch (3580 m a.s.l.).

Author

Motos, Ghislain, Schmale, Julia, Corbin, Joel C., Modini, Robin, Karlen, Nadine, Bertò, Michele, Baltensperger, Urs, and Gysel, Martin

Abstract

Abstract. Liquid clouds form by condensation of water vapour on aerosol particles in the atmosphere. Even black carbon (BC) particles, which are known to be little hygroscopic, have been shown to readily form cloud droplets once they have acquired water-soluble coatings by atmospheric aging processes. Accurately simulating the life cycle of BC in the atmosphere, which strongly depends on the wet removal following droplet activation, has recently been identified as a key element for accurate prediction of the climate forcing of BC. Here, to assess BC activation in detail, we performed in-situ measurements during cloud events at the Jungfraujoch high mountain station in Switzerland in summer 2010 and 2016. Cloud droplet residual and interstitial (unactivated) particles as well as the total aerosol were selectively sampled using different inlets, followed by their physical characterization using scanning mobility particle sizers (SMPSs), multi-angle absorption photometers (MAAPs) and a single particle soot photometer (SP2). By calculating cloud droplet activated fractions with these measurements, we determined the roles of various parameters on the droplet activation of BC. The half-rise threshold diameter for droplet activation (Dhalfcloud), i.e. the size above which aerosol particles formed cloud droplets, was inferred from the aerosol size distributions measured behind the different inlets. The effective peak supersaturation (SSpeak) of a cloud was derived from Dhalfcloud by comparing it to the supersaturation dependence of the threshold diameter for cloud condensation nuclei (CCN) activation measured by a CCN counter (CCNC). In this way we showed that the mass-based scavenged fraction of BC strongly correlates with that of the entire aerosol population because SSpeak modulates the critical size for activation of either particle type. Fifty percent of the BC-containing particles with a BC mass equivalent core diameter of 90nm were activated in clouds with SSpeak≈0.21%, increasing up to ~80% activated fraction at SSpeak≈0.5%. On a single particle basis, BC activation at a certain SSpeak is controlled by the BC core size and internally mixed coating which increases overall particle size and hygroscopicity. However, the resulting effect on the population averaged and on the size integrated BC scavenged fraction by mass is small for two reasons: first, acquisition of coatings only matters for small cores in clouds with low SSpeak and, second, variations in BC core size distribution and mean coating thickness are limited in the lower free troposphere in summer. [ABSTRACT FROM AUTHOR]

Published
2018
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32. Size-resolved and integral measurements of cloud condensation nuclei (CCN) at the high-alpine site Jungfraujoch

Author

Rose, Diana, Gunthe, Sachin S., Jurányi, Zsófia, Gysel, Martin, Frank, Göran P., Schneider, Johannes, Curtius, Joachim, and Pöschl, Ulrich

Subjects
ddc:550
Abstract

As part of the CLACE-6 campaign we performed size-resolved CCN measurements for a~supersaturation range of S = 0.079 % to 0.66% at the high-alpine research station Jungfraujoch, Switzerland, in March~2007. The derived effective hygroscopicity parameter κ describing the influence of particle composition on CCN activity was on average 0.23–0.30 for Aitken (50–100 nm) and 0.32–0.43 for accumulation mode particles (100–200 nm). The campaign average value of κ = 0.3 is similar to the average value of κ for other continental locations. When air masses came from southeasterly directions crossing the Po Valley in Italy, particles were much more hygroscopic (κ ≈ 0.42) due to large sulfate mass fractions. The κ values obtained at S = 0.079 % exhibited a good negative correlation with the organic mass fractions derived from PM1 aerosol mass spectrometer (AMS) measurements. Applying a simple mixing rule the organic and inorganic mass fractions observed by the AMS could be used to reproduce the temporal fluctuations of the hygroscopicity of accumulation mode particles quite well. We show how during a cloud event the aerosol particles were activated as cloud droplets and then removed from the air by precipitation leaving behind only a small amount of accumulation mode particles consisting mainly of weakly CCN-active particles, most likely externally mixed unprocessed soot particles. During the campaign we had the opportunity to directly compare two DMT CCN counters for a certain time. The total CCN concentration (NCCN,tot) obtained by the two instruments at equal supersaturations agreed well for both possible operating modes: detecting NCCN,tot directly by sampling the polydisperse aerosol with the CCNC, or indirectly by combining size-resolved measurements of the activated fraction with parallel measurements of the particle size distribution (e.g., by SMPS). However, some supersaturation setpoints differed between the two CCNCs by as much as 20% after applying the instrument calibrations, which resulted in differences of the corresponding NCCN,tot of up to 50%. This emphasizes that it is extremely important to carefully calibrate the supersaturation of the instrument, especially at low S.

Published
2013

33. Supplementary material to "Evaluation of the absorption Ångström exponents for traffic and wood burning in the Aethalometer based source apportionment using radiocarbon measurements of ambient aerosol"

Author

Zotter, Peter, primary, Herich, Hanna, additional, Gysel, Martin, additional, El-Haddad, Imad, additional, Zhang, Yanlin, additional, Močnik, Griša, additional, Hüglin, Christoph, additional, Baltensperger, Urs, additional, Szidat, Sönke, additional, and Prévôt, André S. H., additional

Published
2016
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34. Evaluation of the absorption Ångström exponents for traffic and wood burning in the Aethalometer based source apportionment using radiocarbon measurements of ambient aerosol

Author

Zotter, Peter, primary, Herich, Hanna, additional, Gysel, Martin, additional, El-Haddad, Imad, additional, Zhang, Yanlin, additional, Močnik, Griša, additional, Hüglin, Christoph, additional, Baltensperger, Urs, additional, Szidat, Sönke, additional, and Prévôt, André S. H., additional

Published
2016
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35. Vertical profiling of aerosol hygroscopic properties in the planetary boundary layer during the PEGASOS campaigns

Author

Rosati, Bernadette, primary, Gysel, Martin, additional, Rubach, Florian, additional, Mentel, Thomas F., additional, Goger, Brigitta, additional, Poulain, Laurent, additional, Schlag, Patrick, additional, Miettinen, Pasi, additional, Pajunoja, Aki, additional, Virtanen, Annele, additional, Klein Baltink, Henk, additional, Henzing, J. S. Bas, additional, Größ, Johannes, additional, Gobbi, Gian Paolo, additional, Wiedensohler, Alfred, additional, Kiendler-Scharr, Astrid, additional, Decesari, Stefano, additional, Facchini, Maria Cristina, additional, Weingartner, Ernest, additional, and Baltensperger, Urs, additional

Published
2016
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36. Studying the vertical aerosol extinction coefficient by comparing in situ airborne data and elastic backscatter lidar

Author

Rosati, Bernadette, primary, Herrmann, Erik, additional, Bucci, Silvia, additional, Fierli, Federico, additional, Cairo, Francesco, additional, Gysel, Martin, additional, Tillmann, Ralf, additional, Größ, Johannes, additional, Gobbi, Gian Paolo, additional, Di Liberto, Luca, additional, Di Donfrancesco, Guido, additional, Wiedensohler, Alfred, additional, Weingartner, Ernest, additional, Virtanen, Annele, additional, Mentel, Thomas F., additional, and Baltensperger, Urs, additional

Published
2016
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37. Chemical and physical influences on aerosol activation in liquid clouds: a study based on observations from the Jungfraujoch, Switzerland

Author

Hoyle, Christopher R., primary, Webster, Clare S., additional, Rieder, Harald E., additional, Nenes, Athanasios, additional, Hammer, Emanuel, additional, Herrmann, Erik, additional, Gysel, Martin, additional, Bukowiecki, Nicolas, additional, Weingartner, Ernest, additional, Steinbacher, Martin, additional, and Baltensperger, Urs, additional

Published
2016
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39. Droplet activation behaviour of atmospheric black carbon particles in fog as a function of their size and mixing state.

Author

Motos, Ghislain, Schmale, Julia, Corbin, Joel Christopher, Zanatta, Marco, Baltensperger, Urs, and Gysel, Martin

Abstract

Among the variety of particle types present in the atmosphere, black carbon (BC), emitted by combustion processes, is uniquely associated with harmful effects to the human body and substantial radiative forcing of the Earth. Pure BC is known to be non-hygroscopic, but its ability to acquire a coating of hygroscopic organic and inorganic material leads to increased hygroscopicity as well as diameter, facilitating droplet activation. This affects BC radiative forcing through aerosol-cloud interactions (aci) and BC life cycle. To gain insights into these processes, we performed a field campaign in winter 2015/16 in a residential area of Zurich which aimed at distinguishing different particle mixing states regarding hygroscopic properties in the cloud condensation nuclei (CCN)-activated fraction spectrum of urban aerosol and establishing relations between the mixing state of BC and its activation to form droplets in fog. This was achieved by operating a CCN counter (CCNC), a scanning mobility particle sizer (SMPS), a single particle soot photometer (SP2) and an aerosol chemical speciation monitor (ACSM) behind a combination of a total- and an interstitial-aerosol inlet. Our results indicate that, depending on the time of the day, we sampled both heavily aged internally mixed BC from background air advected to the site and freshly emitted externally mixed BC from local or regional traffic sources. During rush hours in the morning of weekdays, we found clear evidence that the enhanced traffic emissions caused peaks in the number fraction of externally mixed BC particles which do not act as CCN within the CCNC. The mixing state of BC particles was also found to play a key role in their ability to form fog droplets. The very low effective peak supersaturations (SSpeak) occurring in fog (between approximately 0.03 and 0.06 % during this campaign) restrict droplet activation to a minor fraction of the aerosol burden (around 0.5 to 1 % of total particle number concentration between 20 and 593 nm) leading to very selective criteria on diameter and chemical composition. We show that bare BC cores are unable to activate to fog droplets at such low SSpeak, while BC particles surrounded by thick coating have a very similar activation behavior as BC-free particles. The threshold coating thickness required for activation was shown to decrease with increasing BC core size. Using simplified κ-Köhler theory combined with the ZSR mixing rule assuming spherical core-shell particle geometry constrained with single particle measurements of respective volumes, we found good agreement between the predicted and the directly observed size and mixing state resolved droplet activation behaviour of BC-containing particles in fog. This successful closure demonstrates the predictability of their droplet activation in fog with a simplified theoretical model only requiring size and mixing state information, which can also be applied in a consistent manner in model simulations. [ABSTRACT FROM AUTHOR]

Published
2018
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41. Analysis of long‐term aerosol size distribution data from Jungfraujoch with emphasis on free tropospheric conditions, cloud influence, and air mass transport

Author

Herrmann, Erik, primary, Weingartner, Ernest, additional, Henne, Stephan, additional, Vuilleumier, Laurent, additional, Bukowiecki, Nicolas, additional, Steinbacher, Martin, additional, Conen, Franz, additional, Collaud Coen, Martine, additional, Hammer, Emanuel, additional, Jurányi, Zsofia, additional, Baltensperger, Urs, additional, and Gysel, Martin, additional

Published
2015
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42. Relating hygroscopicity and composition of organic aerosol particulate matter

Author

Duplissy, Jonathan, DeCarlo, Peter F., Dommen, Josef, Alfarra, M. Rami, Metzger, Axel, Barmpadimos, Iakovos, Prevot, André Stephan Henry, Weingartner, Ernest, Tritscher, Torsten, Gysel, Martin, Aiken, Allison C., Jimenez, Jose Luis, Canagaratna, Manjula R., Worsnop, Douglas R., Collins, Donald R., Tomlinson, Jason M., and Baltensperger, Urs

Subjects
ddc:550
Abstract

A hygroscopicity tandem differential mobility analyzer (HTDMA) was used to measure the water uptake (hygroscopicity) of secondary organic aerosol (SOA) formed during the chemical and photochemical oxidation of several organic precursors in a smog chamber. Electron ionization mass spectra of the non-refractory submicron aerosol were simultaneously determined with an aerosol mass spectrometer (AMS), and correlations between the two different signals were investigated. SOA hygroscopicity was found to strongly correlate with the relative abundance of the ion signal m/z 44 expressed as a fraction of total organic signal (f44). m/z 44 is due mostly to the ion fragment CO2+ for all types of SOA systems studied, and has been previously shown to strongly correlate with organic O/C for ambient and chamber OA. The analysis was also performed on ambient OA from two field experiments at the remote site Jungfraujoch, and the megacity Mexico City, where similar results were found. A simple empirical linear relation between the hygroscopicity of OA at subsaturated RH, as given by the hygroscopic growth factor (GF) or "ϰorg" parameter, and f44 was determined and is given by ϰorg = 2.2 × f44 − 0.13. This approximation can be further verified and refined as the database for AMS and HTDMA measurements is constantly being expanded around the world. The use of this approximation could introduce an important simplification in the parameterization of hygroscopicity of OA in atmospheric models, since f44 is correlated with the photochemical age of an air mass.

Published
2010

44. Autarke drahtlose Fernbedienung

Author

Koller, Philippe, Meli, Marcel, Gysel, Martin, and Wuerms, Martin

Subjects
Energy harvesting, 530: Physik, Low power, Wireless, 621.3: Elektrotechnik und Elektronik
Abstract

patent submitter:EM Microelectronic-Marin SA La présente invention concerne le domaine des commandes à distance sans fil et auto-alimentées, c'est-à-dire électriquement autonomes. Par auto-alimenté ou électriquement autonome, on comprend un dispositif non relié au réseau et n'ayant pas de batterie à changer ou à recharger périodiquement par un utilisateur, mais ayant ses propres moyens de génération d'énergie électrique en transformant de l'énergie provenant de l'environnement ou de l'énergie produite par l'utilisateur, notamment lors de l'actionnement du dispositif. Les dispositifs alimentés par des cellules photovoltaïques entrent dans cette catégorie ; toutefois cette source d'énergie nécessite de la lumière, laquelle peut faire défaut.

Published
2010

45. Bidirectional 868/915 MHz wireless module powered with energy harverster

Author

Meli, Marcel, Blättler, Samuel, Gysel, Martin, and Kunz, Valentin

Subjects
Energy harvesting, Bidirectional, Battery-less, Wireless, 333.79: Energie, 004: Informatik
Abstract

In this paper, we present a work that allows bidirectional communications in the 868/915 MHz ISM bands, using the power generated by energy harvesters. Our investigations show that a clear channel assessment, receive of acknowledge and resend of the message are possible within a limited, but reasonable time. The design relies on the use of low power microcontrollers and transceivers, and low energy management techniques.

Published
2008

46. Connecting IEEE 802.15.4 / ZigBee devices in difficult physical Environments

Author

Gysel, Martin and Meli, Marcel

Subjects
Powerline, ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, 004: Informatik, Interference, Signal strength, Gateway
Abstract

One of the problems faced in the use of wireless networks in a multi-storey building is the damping effect of walls. Radio signals can be strongly attenuated, which results in poor or even impossible communication. In such cases, routers are often used to provide continuity. However, depending on the number of routers, this solution could lead to higher costs. In this paper, we present a low cost alternative. We use available modules to show how distant devices can easily be connected. We first discuss the requirements of such a connection with regards to 802.15.4 / ZigBee, and then present our hardware and software solutions.

Published
2008

47. Low cost solutions to pairing issues in IEEE 802.15.4 networks

Author

Meli, Marcel, Gysel, Martin, and Würms, Martin

Subjects
RFID, Wireless, 802.15.4, Pairing, 006: Spezielle Computerverfahren
Abstract

The last years have seen an important increase in the development and proliferation of wireless technologies. This success, mostly related to mobility and the relative ease with which wireless devices can be linked (no wires needed between parties), has affected consumer as well as industrial applications. There are however many areas that are still closed to the introduction of wireless systems. Among the factors that affect wireless acceptance, one can name security and the complexity often involved in setting up networks. Unlike wired systems, the extra confidence afforded by “seen wires” is not available in wireless systems, making it difficult for the users to know if communication occurs between legitimate parties. This places wireless technology before the need to introduce simple methods to improve the set up and authentication processes. These aspects are addressed by binding methods. It is our purpose in this document to present such solutions, and especially how they can be used in 802.15.4 based networks. We will mainly focus on solutions involving optical or RFID techniques. We will also suggest some improvements where needed.

Published
2007
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49. Aerosol-Cloud Interactions in the Lower Free Troposphere as Measured at the High Alpine Research Station Jungfraujoch in Switzerland

Author

Weingartner, Ernest, Verheggen, Bart, Cozic, Julie, Gysel, Martin, Sjorgen, Staffan, Duplissy, Jonathan, Lohmann, Ulrike, Mertes, Stefan, Bower, Keith N., Flynn, Michael, Connolly, Paul, Crosier, Jonathan, Gallagher, Martin, Coe, Hugh, Choularton, Tom, Walter, Saskia, Schneider, Johannes, Curtius, Joachim, Borrmann, Stephan, Petzold, Andreas, Ebert, Martin, Inerle-Hof, M., Worringen, A., Weinbruch, Stephan, Fries, E., Starokozhev, Elena, Püttmann, Wilhelm, Jaeschke, Wolfgang, Vana, M., Hirsikko, A., Tamm, E., Aalto, P., and Kulmala, Markku

Subjects
Atmospheric Nucleation, Atmosphärische Spurenstoffe, Measurement Campaigns, Cloud/Fog Aerosol Interactions
Abstract

Within the WMO Global Atmosphere Watch (GAW) program continuous measurements of aerosol parameters have been performed at the Jungfraujoch high Alpine site since 1988. This measurement site is located on an exposed mountain col in the Bernese Alps, Switzerland, at 3580 meters altitude. Throughout the year the station is within clouds about 40% of the time. In warm months, the site is influenced by injection of planetary boundary layer air into the free troposphere during sunny afternoons due to thermal convection, while in winter it is usually in the undisturbed free troposphere. Several intensive field studies, named CLACE (Cloud and Aerosol Characterization Experiment), have been performed in both summer and winter within international collaborations. State-of-the-art instrumentation is employed to characterize the aerosol size distribution (Scanning Mobility Particle Sizer, SMPS; Optical Particle Counter, OPC). The University of Manchester and the Max Planck Institute in Mainz operated two Aerodyne Aerosol Mass Spectrometers (AMS) to measure the size segregated chemical composition. Other measured parameters were the hygroscopic properties of the particles (Hygroscopicity Tandem Differential Mobility Analyzer, H-TDMA), cloud microphysics (Particulate Volume Monitor, PVM; Forward Scattering Spectrometer Probe, FSSP; Cloud Particle Imager, CPI), and particle morphology (Environmental Scanning Electron Microscope, ESEM). An Air Ion Spectrometer (AIS) and an outdoor SMPS were also employed. The latter two instruments are especially well suited to measure nanometer sized particles (charged particles and sum of neutral and charged particles, respectively) in order to elucidate their formation mechanisms and rates. Different inlets are used for these instruments: A heated inlet (25°C) designed to prevent ice build-up and to evaporate cloud particles at an early stage, ensuring that the cloud condensation nuclei and/or ice nuclei are also sampled. This is called the total inlet. An interstitial inlet operated with a PM2 cyclone impactor removed all cloud droplets and ice crystals from the ambient air. Within a cloud the sampled air thus represents the interstitial (or unactivated) aerosol fraction. In addition, the Institute for Tropospheric Research (IFT) operated a Counterflow Virtual Impactor (CVI, Mertes et al., 2005). The CVI was part of a new prototype sampling system (Ice-CVI) that allows for the separation of small ice particles from large ice crystals, cloud droplets and interstitial aerosol particles. The extracted ice particles are dried airborne in the system and the remaining residual particles which correspond to the former ice nuclei were analyzed with a variety of different instruments. Differencing the response downstream of the different inlets provides insight in the fractionation of aerosol particles between the cloud phase and the interstitial phase.

Published
2006

50. Using IEEE 802.15.4/ZigBee in audio applications

Author

Meli, Marcel, Gysel, Martin, and Sommerhalder, Marc

Subjects
ZigBee, Audio, ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, Compression, 802.15.4, 004: Informatik, ComputerSystemsOrganization_SPECIAL-PURPOSEANDAPPLICATION-BASEDSYSTEMS
Abstract

Most of the current uses for ZigBee and IEEE 802.15.4 focus on control applications. However, there are other areas that will benefit from the standardisation, low cost and possibly low power of ZigBee/IEEE 802.15.4. This paper focuses on the use of ZigBee/IEEE802.15.4 for audio applications. We will discuss the advantages and theoretical limits of ZigBee/IEEE 802.15.4 for this kind of applications. We will then present a design that we used as starting point to develop applications related to the transfer of audio data.

Published
2006
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