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Laboratory studies on the ice nucleation properties of fresh and aged mineral dust aerosols

English title Laboratory studies on the ice nucleation properties of fresh and aged mineral dust aerosols
Applicant Lohmann Ulrike
Number 150169
Funding scheme Project funding (Div. I-III)
Research institution Institut für Atmosphäre und Klima ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Climatology. Atmospherical Chemistry, Aeronomy
Start/End 01.11.2013 - 31.10.2015
Approved amount 345'284.00
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Keywords (4)

Cloud microphysics; Ice crystal formation; Fresh and aged mineral dust aerosols; Laboratory studies

Lay Summary (German)

Lead
Menschliche Aktivitäten führen zu Emissionen von Spurengases. Neben den Treibhausgasen gibt es auch solche Spurengase, die Aerosole (Feinstaub) verändern, was einen Einfluss auf die Eisbildung in Wolken haben könnte. Diesen möglichen Einfluss studieren wir in diesem Projekt, indem wir Mineralstäube in einem Stahltank zur Oberflächenmodifikation verschiedenen Spurengasen aussetzen. Diese Experimente werden mit in der Atmosphäre gealtertem Mineralstaub verglichen, der z.B. aus der Sahara stammt.
Lay summary

Experimentelle Studie zur Eiskeimfähigkeit von Mineralstaub in Abhängigkeit der Aufenthaltszeit in der Atmosphäre

Menschliche Aktivitäten verändern nicht nur das Klima, sondern auch chemischen Prozesse, die in der Atmosphäre stattfinden. Zum Beispiel führte die Einführung von Filtersystemen in Verkehr und Industrie zu einer starken Verringerung von einigen Spurengasen, was wiederum den Abbau anderer Substanzen verlangsamt hat. Auf der Oberfläche von Mineralstaub Aerosolen (luftgetragen Partikeln) finden Reaktionen mit Spurengasen statt, durch die ihre Oberflächeneigenschaften verändert werden. Sogenannte gealterte Staubpartikel können z.B. leichter Wasser kondensieren oder verlieren die Fähigkeit auf ihrer Oberfläche Eiskristalle wachsen zu lassen. Dadurch ändert sich ihr Einfluss auf die Wolkenbildung, und als Folge davon auf die Niederschlagsverteilung und den Strahlungshaushalt des Planeten.
Die vorliegende Studie zielt auf die Untersuchung des Einflusses von Oberflächenveränderung auf die Eisbildung in Wolken ab.
Es sind verschiedene Mechanismen bekannt wie Mineralstaubpartikel die Eisbildung begünstigen können, wobei das Gefrieren von Tropfen durch Kollisionen bisher noch wenig erforscht ist. Ein erster Schritt dieser Studie besteht darin zu quantifizieren wie häufig Partikel einer bestimmten Grösse von Tropfen eingefangen werden und ob eine Kollision ausreicht, um das Gefrieren des Tropfens bei einer bestimmten Temperatur zu verursachen. Zusammen mit bereits etablierten Experimenten, welche andere Eisbildungsmechanismen simulieren, kann dann der Einfluss von Partikeleigenschaften und Oberflächenmodifikationen untersucht werden. Zur Oberflächenmodifikation werden Mineralstäube in einem Stahltank Spurengasen (z.B. Schwefeldioxid, Stickoxide, Ozon) ausgesetzt. Diese Experimente werden mit in der Atmosphäre gealtertem Mineralstaub verglichen, der z.B. aus der Sahara stammt.
Direct link to Lay Summary Last update: 17.10.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Comparing contact and immersion freezing from continuous flow diffusion chambers
Nagare Baban, Marcolli Claudia, Welti Andre, Stetzer Olaf, Lohmann Ulrike (2016), Comparing contact and immersion freezing from continuous flow diffusion chambers, in Atmospheric Chemistry and Physics, 16, 8899-8914.
Ice Nucleating Particle Measurements at 241 K during Winter Months at 3580 m MSL in the Swiss Alps
Boose Yvonne, Kanji Zamin A., Kohn Monika, Sierau Berko, Zipori Assaf, Crawford Ian, Lloyd Gary, Bukowiecki Nicolas, Herrmann Erik, Kupiszewski Piotr, Steinbacher Martin, Lohmann Ulrike (2016), Ice Nucleating Particle Measurements at 241 K during Winter Months at 3580 m MSL in the Swiss Alps, in Journal of the Atmospheric Sciences , 73, 2203-2228.
Ice nucleating particles in the Saharan Air Layer
Boose Yvonne, Sierau Berko, Garcia Isabel M, Rodríguez Sergio, Alastuey Andrés, Linke Claudia, Schnaiter Martin, Kupiszewski Piotr, Kanji Zamin A, Lohmann Ulrike (2016), Ice nucleating particles in the Saharan Air Layer, in Atmospheric Physics and Chemistry , 16, 9067-9087.
Ice nucleation efficiency of AgI: review and new insights
Marcolli Claudia, Nagare Baban, Welti Andre, Lohmann Ulrike (2016), Ice nucleation efficiency of AgI: review and new insights, in Atmospheric Chemistry and Physics, 2016, 8915-8937.
Comparison of measured and calculated collision efficiencies at low temperatures
Nagare Baban, Marcella Claudia, Stetzer Olaf, Lohmann Ulrike (2015), Comparison of measured and calculated collision efficiencies at low temperatures, in Atmospheric Chemistry and Physics, 15, 13759-13776.
Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles
Kanji Zamin A., Welti Andre, Chou Cedric, Stetzer Olaf, Lohmann Ulrike (2013), Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles, in Atmospheric Chemistry and Physics, 13, 909-9118.
Heterogeneous ice nucleation on dust particles sourced from 9 deserts worldwide – Part 1: Immersion freezing
Boose Yvonne, Welti Andre, Atkinson James, Ramelli Fabiola, Danielczok Anja, Bingemer Heinz G., Plötze Michael, Sierau Berko, Kanji Zamin A., Lohmann Ulrike, Heterogeneous ice nucleation on dust particles sourced from 9 deserts worldwide – Part 1: Immersion freezing, in Atmospheric Chemistry and Physics , Accepted(N/A), N/A-N/A.

Collaboration

Group / person Country
Types of collaboration
Dr. Frank Stratmann, Department of Physics, Leibniz-Institut für Troposphärenforschung, Leipzig Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Prof. Urs Baltensperger, Paul Scherrer Institut, Villigen Switzerland (Europe)
- Publication
- Research Infrastructure
Dr. Johannes Schneider, Max-Planck Institut für Chemie, Mainz Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Dr. Paul DeMott, Colorado State University, USA United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
- Exchange of personnel
Dr. Sergio Rodriguez, Centro de Investigación Atmosférica de Izaña, Teneriffa Spain (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
American Chemical Society Talk given at a conference Immersion Ice Nucleation Properties of Feldspar Minerals 16.08.2015 Boston, MA, United States of America Kanji Zaminhussein; Lohmann Ulrike; Welti André;
ETH Department of Environmental Systems Science Conference Talk given at a conference Atmospheric Ice Nucleation: The link between air quality and rock mineralogy 01.06.2015 Davos, Switzerland Lohmann Ulrike; Welti André; Kanji Zaminhussein;
American Geophysical Union Poster Ice nucleation of Snomax® particles below water vapor saturation: immersion freezing in concentrated solution droplets 14.12.2014 San Francisco, CA, United States of America Boose Yvonne Carola; Kanji Zaminhussein;
International Aerosol Conference (IAC) Talk given at a conference On the Requirements of Active Ice Nuclei in the Immersion Mode 31.08.2014 Busan, Korean Republic (South Korea) Kanji Zaminhussein; Lohmann Ulrike; Welti André;
14th Conference on Cloud Physics, American Meteorological Society Talk given at a conference Ice nuclei concentrations in the free troposphere 07.07.2014 Boston, MA, United States of America Sierau Berko; Kanji Zaminhussein; Lohmann Ulrike; Boose Yvonne Carola;
American Meteorological Society Poster Laboratory Studies of Immersion Mode Ice Nucleation on Five Types of Black Carbon Samples 07.07.2014 Boston, MA, United States of America Lohmann Ulrike; Welti André; Kanji Zaminhussein; Sierau Berko;
European Geo[physical Union Talk given at a conference Is there a lower size limit for mineral dust ice nuclei in the immersion mode? 27.04.2014 Vienna, Austria Welti André; Kanji Zaminhussein; Lohmann Ulrike;
Workshop on Atmospheric Ice Nucleation, European Science Foundation Talk given at a conference In-situ detection of ice nuclei concentrations in the free troposphere in the deposition and condensation regime 26.04.2014 Vienna, Austria Lohmann Ulrike; Sierau Berko; Boose Yvonne Carola; Kanji Zaminhussein;
American Meteorological Society Poster Does a lower size limit for mineral dust ice nuclei in the immersion mode exist? 02.02.2014 Atlanta, Georgia, United States of America Lohmann Ulrike; Kanji Zaminhussein; Welti André;
American Meteorological Society, 94th Annual Meeting Talk given at a conference Ice nuclei properties in the Saharan Air Layer close to the source – Results from the CALIMA2013 campaign 02.02.2014 Atlanta, Georgia, United States of America Sierau Berko; Lohmann Ulrike; Boose Yvonne Carola; Kanji Zaminhussein;


Self-organised

Title Date Place

Knowledge transfer events

Active participation

Title Type of contribution Date Place Persons involved
Luftlabor Performances, exhibitions (e.g. for education institutions) 01.11.2015 Locarno, Zurich, Neuchatel, Switzerland Boose Yvonne Carola;


Awards

Title Year
ETH Silver Medal for Outstanding Doctoral Thesis 2016
ETH Silver Medal for Outstanding Doctoral Thesis 2013

Associated projects

Number Title Start Funding scheme
127275 Laboratory and Field Studies of Ice Nucleation: Natural and Anthropogenic Effects 01.11.2009 Project funding (Div. I-III)
152813 Measurements of water uptake by fresh and aged wood-burning soot particles in the subsaturated regime 01.12.2014 Project funding (Div. I-III)
156581 Elucidating Ice Nucleation Mechanisms Relevant to the Atmosphere: Is deposition nucleation really immersion freezing in pores? 01.02.2015 Project funding (Div. I-III)
132199 Field and laboratory studies of the chemical composition and mixing state of black carbon particles and their ability to act as cloud condensation and ice nuclei 01.11.2010 Project funding (Div. I-III)
127275 Laboratory and Field Studies of Ice Nucleation: Natural and Anthropogenic Effects 01.11.2009 Project funding (Div. I-III)

Abstract

Clouds can be composed of ice crystals and/or water droplets. The relative abundance, sizes and shapes of these hydrometeors determine the radiative properties of clouds. The Earth’s climate is a strong function of the balance of incoming and outgoing radiation and therefore if cloud composition changes due to anthropogenic emissions it is important to assess the climate impact of these emissions. A detailed knowledge of all underlying and contributing processes to the radiative balance is necessary for this assessment. Ice in clouds forms via homogeneous and heterogeneous ice nucleation. For the latter, insoluble particles termed ice nuclei (IN) are required as catalysts to aid the ice formation process. Of the four heterogeneous ice nucleation processes, contact freezing is the least understood mechanism for which only limited experimental data is available. One reason for this is that contact freezing is a two-step process and to fully understand and quantify contact freezing, both steps need to be treated and preferentially measured independently. The two steps are the collision of a droplet with an aerosol particle, followed by the freezing of the droplet as a result of the collision, which in turn depends on ambient temperature conditions. Ultimately, a full microphysical characterization of an ice nucleus in all heterogeneous nucleation modes is needed to improve our understanding of the relative importance of the different nucleation modes for cloud formation processes.The most important IN in the atmosphere are mineral dust particles originating from desert regions such as the Sahara and Gobi deserts. Through anthropogenic activities, reactive trace gases such as O3, SO2, and NOx (nitric oxides) can be emitted into the atmosphere either directly or be formed by secondary processes caused by emissions of precursors. These reactive trace gases can also interact with existing particles like mineral dust and modify their properties such as hygroscopicity and chemical composition such that they can aid warm cloud formation by acting as condensation nuclei (CCN) or cold cloud formation by acting as IN. Motivated by such interactions in the troposphere we propose the following research objectives for this project: 1.To better quantify the collision of an aerosol particle with a supercooled droplet, using systematic laboratory measurements of the collisions between droplets and particles2.To measure contact freezing experimentally and infer from these the experiment-independent particle property “freezing efficiency” by using the data from objective 1 to de-convolve the collision from the freezing step in contact freezing.3.To quantify how reactions with trace gases modify the properties of dust samples (surrogates and Saharan dust sampled from the atmosphere) and their abilities to act as CCN and IN in all four heterogeneous ice nucleation modes.4.To characterize airborne Saharan dust sampled from the atmosphere chemically, physically, and mineralogically complementing the experiments mentioned under objective 3.
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