Dr. Thorsten Bartels-RauschScientist
Paul Scherrer Institute
5232 Villigen PSI
Telephone: +41 56 310 4301
Research activitiesSnow and ice are chemically active. The resulting fluxes of nitrogen oxides and volatile organics impact air quality and climate change. Snow can also trap trace gases, such as toxic mercury, from the atmosphere. During snow melt these contaminants are released to the aquatic environment where they can enter the food web. Those large-scale effects within the Earth system have been partially assigned to chemical processes in ice and snow. (Bartels-Rausch et al., Atmospheric Chemistry and Physics 14, 1587-1633, 2014) To better understand these processes on a fundamental level, we do laboratory based experiments:
- investigate the interaction of trace gases with ice on a molecular level taking full advantage of core-level spectroscopy at the Swiss Light Source of PSI (SLS).
- investigate the physical interactions and chemical reactivity of trace impurities in snow and ice in larger-scale experimental systems that perfectly mimic environmental settings. This work is realized in ongoing co-operations with Martin Schneebeli (WSL-SLF) and more recently with Anja Eichler (PSI).
Hunting liquid micro-pockets in snow and ice by core level spectroscopyThorsten Bartels-Rausch
We use electron- and fluorescence yield near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to probe the local environment of chlorine ions in frozen NaCl-water binary systems. NEXAFS spectra reflect the binding environment of the probe and thus reveal phase changes in aqueous solutions. Switching between electron and fluorescence detection allows to either probe barely the air-ice interface or the bulk of the sample. The goal is to describe frapant differences in the phases of NaCl - water mixtures at temperatures blow the freezing point for the surface of the ice vs. its bulk. This has significant impact on modelling chemical reactions in snow or ice and it’s environmental consequences.
The limited inelastic mean free path of electrons (red arrow) in solid matter restricts the probing depth to the air-ice interface. When fluorescence photons are detected, the probing depth reaches deep into the bulk of the sample (red wave)
Trace gas uptake: The role of grain boundariesAngela Hong
In this project, we aim to gain molecular-level insight to the macroscopic phenomenon of atmospheric trace gas uptake to ice, a process that arises from the intersection of ice microstructure and a compound’s physicochemical properties. To this end, we design and develop a flow reactor system featuring a novel Drilled Ice Flow Tube (DIFT). By varying the degree of crystallinity of the DIFT, we can test various uptake mechanisms, such as surface adsorption and bulk accommodation into the crystal and grain boundaries. Developing a mechanistic description of the fate of trace gases in ice will enable us to better understand the chemical role of snow in these coupled environments, the degree to which reactive trace gases are recycled back into the atmosphere, the composition and oxidative capacity of the snow pack and atmosphere, and move us towards reconciling field observations, models, and laboratory experiments.
To identify important uptake mechanisms of trace gases to ice, we designed a drilled ice flow tube (DRIFT)
Reactivity of contaminants in snowJacinta Edebeli :: Miso Project
We focus on the chemical reactivity of ozone with halide salts in snow. These reactions are of significant environmental interest because they have been linked to vast ozone depletion events regularly observed in the Polar Regions and mid-latitudes. With the application of coated wall flow-tube experiments, the aim of this study is to investigate the reactivity of halide salts when temperatures decrease. Our hypothesis is that viscosity and phase changes with temperature influence heterogeneous reaction rates and products beyond a purely temperature effect.
The phase of aerosol particles in snow changes with decreasing temperatures from liquid (green circles) to solid (yellow hexagons). As consequence, reactive processes in the bulk would become less feasible, while surface reactions occur remain in operation. (3-dimensional µCT reconstruction of snow: Schneebeli, WSL-SLF Davos).
Ice - acidic trace gas interactions:A molecular perspective at PSI/SLSAstrid Waldner
Ice - trace gas interactions have the capability to influence and modify the composition and oxidation capacity of our atmosphere. Trace gases can be taken up or implemented by ice, and subsequently react forming products potentially emitted back to the gas phase. The ice structure may also be modified by trace gasses. These processes are recognized as important for understanding phenomena occurring in our atmosphere, cryosphere and biosphere but until now, there has been no commonly accepted picture describing ice-trace gas interactions on a molecular basis. Within this project we examine the interaction of various acidic trace gases (e.g. HCOOH and HONO) with ice using ambient pressure X-ray spectroscopy. Experiments are performed at environmentally relevant conditions, meaning the ice temperature can remain close to its melting point and for low trace gas concentrations. Using this set-up we analyze if acid molecules penetrates in ice and whether the interaction modifies the ice structure.
Picture of crystalline ice sample. Potential interaction processes are shown: adsorption to the ice surface, chemical reaction (dissociation), diffusion, and modification of the surface.
- I studied chemistry in Würzburg (Germany), Trondheim (Norway) and at the Swiss Federal Institute of Technology in Zürich (ETH) where I received my master degree in 1999. Master thesis at the Swiss Federal Institute for Aquatic Science and Technology (Eawag) with a work on the trace analysis of organic pesticides in water samples.
- PhD at the University of Berne (2003) under the supervision of Heinz Gäggeler and Markus Ammann (Paul Scherrer Institute): Uptake of atmospheric trace gases on ice and snow surfaces. Thermodynamic description of adsorption processes. Work on the effect of snow properties on adsorption processes.
- Post-Doc at the University of Toronto (Canada) with work in the laboratory of Jamie Donaldson and of Jon Abbatt. Investigation of the photolysis of nitrogen oxides on snow surfaces. Development of an experimental method to better characterise the ice surface and understand its role during uptake processes.
- Since 2006 scientist in surface chemistry group at the Paul Scherrer Institute.
The environmental photochemistry of oxide surfaces and the nature of frozen salt solutions: A new in situ XPS approach
Topics in Catalysis 59, 591-604 (2016).DOI: 10.1007/s11244-015-0515-5
Viscosity controls humidity dependence of N2O5 uptake to citric acid aerosol
Atmospheric Chemistry and Physics 15, 13615-13625 (2015).DOI: 10.5194/acp-15-13615-2015
Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: A strong source from surface snow?
Atmospheric Chemistry and Physics 14, 9963-9976 (2014).DOI: 10.5194/acp-14-9963-2014
Production and use of 13N labeled N2O5 to determine gas–aerosol interaction kinetics
Radiochimica Acta 102, 1025 (2014).DOI: 10.1515/ract-2014-2244
Emerging areas in atmospheric photochemistry. In: Topics in Current Chemistry: Atmospheric Chemistry
Springer (Ed.: PA Ariya) 399, 1-53 (2014).DOI: 10.1007/128_2012_393
A review of air–ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow
Atmospheric Chemistry and Physics 14, 1587-1633 (2014).DOI: 10.5194/acp-14-1587-2014
Adsorption of acetic acid on ice studied by ambient-pressure XPS and partial-electron-yield NEXAFS spectroscopy at 230–240 K
Journal of Physical Chemistry A 117, 401-409 (2013).DOI: 10.1021/jp3102332
Diffusion of volatile organics through porous snow: impact of surface adsorption and grain boundaries
Atmospheric Chemistry and Physics 13, 6727-6739 (2013).DOI: 10.5194/acp-13-6727-2013
Chemistry: Ten things we need to know about ice and snow
Nature 494, 27-29 (2013).DOI: 10.1038/494027a
The adsorption of peroxynitric acid on ice between 230 K and 253 K
Atmospheric Chemistry and Physics 12, 1833-1845 (2012).DOI: 10.5194/acp-12-1833-2012
Temporal evolution of surface and grain boundary area in artificial ice beads and implications for snow chemistry
Journal of Glaciology 58, 815-817 (2012).DOI: 10.3189/2012JoG12J058
Organics in environmental ices: Sources, chemistry, and impacts
Atmospheric Chemistry and Physics 12, 9653-9678 (2012).DOI: 10.5194/acp-12-9653-2012
Standard states and thermochemical kinetics in heterogeneous atmospheric chemistry
Journal of Physical Chemistry A 116, 6312-6316 (2012).DOI: 10.1021/jp212015g
Comment on ‘possible contribution of triboelectricity to snow–air interactions’
Environmental Chemistry 9, 119-120 (2012).DOI: 10.1071/EN11147
Ice structures, patterns, and processes: A view across the icefields
Reviews of Modern Physics 84, 885-944 (2012).DOI: 10.1103/RevModPhys.84.885
UVA/VIS-induced nitrous acid formation on polyphenolic films exposed to gaseous NO2
Photochemistry and Photobiology 10, 1680-1690 (2011).DOI: 10.1039/C1PP05113J
A novel synthesis of the N-13 labelled atmospheric trace gas peroxynitric acid
Radiochimica Acta 99, 285-292 (2011).DOI: 10.1524/ract.2011.1830
Photoinduced reduction of divalent mercury in ice by organic matter
Chemosphere 82, 199-203 (2011).DOI: 10.1016/j.chemosphere.2010.10.020
Co-adsorption of acetic acid and nitrous acid on ice
Physical Chemistry Chemical Physics 12, 7194-7202 (2010).DOI: 10.1039/b924782c
Humic acid in ice: Photo-enhanced conversion of nitrogen dioxide into nitrous acid
Atmospheric Environment 44, 5443-5450 (2010).DOI: 10.1016/j.atmosenv.2009.12.025
Interaction of gaseous elemental mercury with snow surfaces: Laboratory investigation
Environmental Research Letters 3, 045009 (2008).DOI: 10.1088/1748-9326/3/4/045009
Uptake of acetone, ethanol and benzene to snow and ice: Effects of surface area and temperature
Environmental Research Letters 3, 045008 (2008).DOI: 10.1088/1748-9326/3/4/045008
Suppression of aqueous surface hydrolysis by monolayers of short chain organic amphiphiles
Physical Chemistry Chemical Physics 9, 1362-1369 (2007).DOI: 10.1039/b617079j
Hono and no2 evolution from irradiated nitrate-doped ice and frozen nitrate solutions
Atmospheric Chemistry and Physics Discussions 6, 10713-10731 (2006).
Atmospheric pressure coated-wall flow-tube study of acetone adsorption on ice
Journal of Physical Chemistry A 109, 4531-4539 (2005).DOI: 10.1021/jp045187l
The partitioning of acetone to different types of ice and snow between 198 and 223 k
Geophysical Research Letters 31, L16110 (2004).DOI: 10.1029/2004GL020070
An atmospheric pressure chemical ionization mass spectrometer (apci-ms) combined with a chromatographic technique to measure the adsorption enthalpy of acetone on ice
International Journal of Mass Spectrometry 226, 279-290 (2003).DOI: 10.1016/S1387-3806(03)00019-8
The adsorption enthalpy of nitrogen oxides on crystalline ice
Atmospheric Chemistry and Physics 2, 235-247 (2002).DOI: 10.5194/acp-2-235-2002
Determination of phenylurea herbicides in natural waters at concentrations below 1 ng 1(-1) using solid-phase extraction, derivatization, and solid-phase microextraction gas chromatography mass spectrometry
Journal of Chromatography A 930, 9-19 (2001).DOI: 10.1016/S0021-9673(01)01192-X