Vienna- Austria - TU Wien · PDF file Vienna- Austria . 7th of April 2018 . Book of Abstracts . Preface. Dear Workshop Participant, It is my pleasure to welcome you to Vienna our 6th

6th Workshop – Microphysics of ice clouds

Vienna- Austria 7th of April 2018

Book of Abstracts

Preface

Dear Workshop Participant, It is my pleasure to welcome you to Vienna at our 6th workshop 'Microphysics of Ice Clouds'. We will bring together three communities of atmospheric ice research: field measurements, laboratory studies and modellers. The joint topic is the ice nucleation in clouds. We will focus on recent observations, and open questions concerning ice formation and development in the atmosphere discussing experimental and theoretical methods including chemistry and microphysics. A particular focus will be heterogeneous ice nucleation. The development of a detailed understanding of ice clouds in the atmosphere relies on the combined use of field studies, modelling at a multitude of scales, and laboratory studies that provide the necessary fundamentals. Atmospheric ice is studied by remote sensing methods from the ground, from airplanes and satellites, or in situ from airborne platforms such as aircraft and balloons. While such observations are essential, the various methods often lack sufficient access to fundamental physic-chemical parameters of ice particles and the involved nucleation process. On the other hand, laboratory studies are usually aimed at understanding the fundamentals of the underlying processes such as the details of the nucleation process, because they can be performed under well controlled conditions. Hence, under these controlled conditions the impact of individual parameters on the ice formation process can be determined. Theoretical and numerical models are then required to transfer the knowledge of laboratory and field studies into small and large-scale models using sensible parameterizations. Moreover, the influence and impact of the nature of pre-existing aerosol particles on ice nucleation efficiency, ice microstructure and ice cloud dynamics are one of the least understood parameters in cloud microphysics. The knowledge of chemists, biologists and crystallographers about the aerosol composition has to be combined with the ice dynamic models of physicists, meteorologists and computational modellers to gain a better understanding of the whole process. For these reasons it seems viable for progress in this area to bring together scientists from various (sub-) disciplines and foster discussions between them. Given the importance of understanding the atmospheric ice nucleation process for various atmospheric applications, e.g. the modelling precipitation and for a representation of clouds in climate models, we believe the topic of the workshop “Microphysics of Ice Clouds” is of high scientific interest for scientists from various disciplines such as meteorology, chemistry, physics, and biology. A workshop provides an ideal platform for more detailed and, thus, deeper interaction between the different communities and provides the opportunity to bring together scientists from the different fields of ice research. Moreover, in contrast to a regular session at the EGU General Assembly with a rapid sequence of contributed talks (typically 12min + 3min of questions), the workshop will provide more time for discussion. This may help abolishing uncertainties and prejudices existing between scientists from different disciplines, in particular for PhD students and postdocs who represent the next generation of scientists. Vienna 7th April 2018 Hinrich Grothe

Local Organizer Prof. Dr. Hinrich Grothe TU Wien Institute of Materials Chemistry www.imc.tuwien.ac.at Email: [email protected] Tel.: +43-664-605886522

Location

Italian Culture Institute

The workshop is held in the "Italian Culture Institute - Istituto Italiano di Cultura" at Ungargasse 43, 1030 Vienna, which is easily accessible by public transport.

Istituto Italiano di Cultura

Map:

Rochusgasse to Ungargasse

Transportation

Sessions Saturday 7th April

12:00 - 13:00 Registration and Buffet

13:00 - 13:10 Opening of the workshop

Hinrich Grothe (Vienna University of Technology)

Ernst Kanitz (Italian Culture Institute, Vienna)

Mixed Session

13:10 - 13:25 1st Talk Philipp Baloh Spectroscopic investigations on organic compounds in desert dust particles

13:25 - 13:30 Discussion

13:30 - 13:45 2nd Talk Ruihao Zhu A Laboratory Study on Immersion Freezing Behavior of Aerosols in Beijing 13:45 - 13:50 Discussion

13:50 - 14:05 3rd Talk Max Port Observations of ice-clouds from deep convective outflow during the Asian monsoon 14:05 - 14:10 Discussion

14:10 - 14:25 4th Talk Jie Chen Freezing activity of droplets containing Humic-acid like substances (HULIS) 14:25 - 14:30 Discussion 14:30 - 14: 45 Break Out Discussion (Coffee &Cakes)

Laboratory Measurements I

14:45 - 15:00 1st Talk Shizuo Fu The Efficiency Spectrum of Ice-Nucleating

Particles and Its Application to the Parameterization of Ice Formation

15:00 - 15:05 Discussion

15:05 - 15:20 2nd Talk Huan Yu Yang Towards the surface science of ice nucleation

on aqueous organic solutions and solid substrates

15:20 - 15:25 Discussion

15:25 - 15:40 3rd Talk Willi Pose Raman investigations on several classes of ice nucleation active aerosols 15:40 - 15:45 Discussion 15:45 - 16:00 Break Out Discussion (Coffee &Cakes)

Laboratory Measurements II

16:00 - 16:15 1st Talk Dominik Heger Looking for the relevance of laboratory experiment to ice clouds 16:15 - 16:20 Discussion

16:20 - 16:35 2nd Talk Jan Voráč Spectroscopy of electrical discharges in contact with water/ice

16:35 - 16:40 Discussion

16:40 - 16:55 3rd Talk Jan Voráč Measurement of reactive radical species in discharges in contact with water/ice

16:55 - 17:00 Discussion 17:00 - 17:15 Break Out Discussion (Coffee &Cakes)

Field Measurements I

17:15 - 17:30 1st Talk Claudia Mignani A case study of biological ice nucleating

particles in the Arctic 17:30 - 17:35 Discussion

17:35 - 17:50 2nd Talk Bruce Moffett Significance of Fresh Water Ice Nucleating

Particles in USA, UK and Mainland European Rivers

17:50 - 17:55 Discussion

17:55 - 18:10 3rd Talk Jessie Creamean

Using spectra characteristics to define ice nucleating particle populations from north and

south of the Alps 18:10 - 18:15 Discussion 18:15 - 18:30 Break Out Discussion (Coffee &Cakes)

Field Measurements II

18:30 - 18:45 1st Talk Veronika Wolf Two totally different Arctic cirrus clouds in February - A case study 18:45 - 18:50 Discussion

18:50 - 19:05 2nd Talk Vaughan Phillips Raindrop-freezing fragmentation in natural

clouds 19:05 - 19:10 Discussion

19:10 - 19:25 3rd Talk Durgesh Nandan Piyush

Diurnal variation of cloud ice water path as observed from SAPHIR onboard Megha-

Tropiques 19:25 - 19:30 Discussion

19:30 - 19:45 4th Talk David Delene Research Aircraft Observations of the Micro-physics of Ice Clouds

19:45 - 19:50 Discussion 19:50 - 20:00 General Discussion 20:00 – 22:00 Dinner & After-Dinner Workshop (optional)

Spectroscopic investigations on organic compounds in desert dust particles

Philipp Baloh1*, Yvonne Boose2,3*, Michael Plötze4, Ulrike Lohmann2, Zamin Kanji2, and Hinrich Grothe1

1Institute of Materials Chemistry, TU Wien, Vienna, Austria;

2ETH Zürich, Institute for Atmospheric and Climate Science, Zürich, Switzerland;

3German Aerospace Center (DLR), Institute for Atmospheric Physics, Oberpfaffenhofen;

4ETH Zürich, Institute for Geotechnical Engineering, Zürich.

* Email: [email protected], [email protected] Mineral dust particles are the most abundant ice nucleating particles (INPs) found in the

atmosphere. Their mineralogical composition in part dictates if they can act as strong INPs or

not. Certain minerals such as microcline show an exceptionally strong ice nucleating

potential, yet its presence in a desert dust particle alone does not seem to be the determining

factor for ice nucleation. In a mixed phase particle, strong ice nucleating minerals may not

come to their full potential due to chemical and mechanical aging that can inactivate their

nucleation sites or due to an interference with compounds that coat the particles, yet only

contribute very little to its overall mass. Carbonic acids, for example, are well known to

hinder ice nucleation to a certain extent and other compounds may simply be able to shield, or

react with the surface in a way that antagonizes the nucleation active sites. What kind of

surface chemicals could be present on dust particles can vary highly depending on the source

of the particle but also on the atmospheric conditions it encounters during transport.

In this study, we investigate how mineralogy, crystal water, and heat labile organic

compounds on dust particles affect the ice nucleating behavior of desert dust collected from

the soil or after atmospheric transport. Before and after heating three dust samples to 573 K,

we measured their ice active surface site density (ns) in the deposition and condensation mode

and used X-ray diffraction (XRD), and Raman- and Infrared- spectroscopy to search for the

cause