ERC FUNDED PROJECTS

The goal of ATOMICAR is to achieve the ultimate sensitivity limit in heterogeneous catalysis: Quantitative measurement of chemical turnover on a single catalytic nanoparticle. Most heterogeneous catalysis occurs on metal nanoparticle in the size range of 3 nm - 10 nm. Model studies have established that there is often a strong coupling between nanoparticle size & shape - and catalytic activity. The strong structure-activity coupling renders it probable that “super-active” nanoparticles exist. However, since there is no way to measure catalytic activity of less than ca 1 million nanoparticles at a time, any super-activity will always be hidden by “ensemble smearing” since one million nanoparticles of exactly identical size and shape cannot be made. The state-of-the-art in catalysis benchmarking is microfabricated flow reactors with mass-spectrometric detection, but the sensitivity of this approach cannot be incrementally improved by six orders of magnitude. This calls for a new measurement paradigm where the activity of a single nanoparticle can be benchmarked – the ultimate limit for catalytic measurement. A tiny batch reactor is the solution, but there are three key problems: How to seal it; how to track catalytic turnover inside it; and how to see the nanoparticle inside it? Graphene solves all three problems: A microfabricated cavity with a thin SixNy bottom window, a single catalytic nanoparticle inside, and a graphene seal forms a gas tight batch reactor since graphene has zero gas permeability. Catalysis is then tracked as an internal pressure change via the stress & deflection of the graphene seal. Crucially, the electron-transparency of graphene and SixNy enables subsequent transmission electron microscope access with atomic resolution so that active nanoparticles can be studied in full detail. ATOMICAR will re-define the experimental limits of catalyst benchmarking and lift the field of basic catalysis research into the single-nanoparticle age.

1 496 000 €

Start date: 2018-02-01, End date: 2023-01-31

Earth's magnetic field plays a fundamental role in our planetary habitat, controlling interactions between the Earth and the solar wind. Here, I propose to use magnetic observations, made simultaneously by multiple satellites, along with numerical models of outer core dynamics, to test whether convective processes can account for ongoing changes in the field. The geomagnetic field is generated by a dynamo process within the core converting kinetic energy of the moving liquid metal into magnetic energy. Yet observations show a region of persistently weak field in the South Atlantic that has grown in size in recent decades. Pinning down the core dynamics responsible for this behaviour is essential if we are to understand the detailed time-dependence of the geodynamo, and to forecast future field changes. Global magnetic observations from the Swarm constellation mission, with three identical satellites now carrying out the most detailed ever survey of the geomagnetic field, provide an exciting opportunity to probe the dynamics of the core in exquisite detail. To exploit this wealth of data, it is urgent that contaminating magnetic sources in the lithosphere and ionosphere are better separated from the core-generated field. I propose to achieve this, and to test the hypothesis that core convection has controlled the recent field evolution in the South Atlantic, via three interlinked projects. First I will co-estimate separate models for the lithospheric and core fields, making use of prior information from crustal geology and dynamo theory. In parallel, I will develop a new scheme for isolating and removing the signature of polar ionospheric currents, better utilising ground-based data. Taking advantage of these improvements, data from Swarm and previous missions will be reprocessed and then assimilated into a purpose-built model of quasi-geostrophic core convection.

1 828 708 €

Start date: 2018-03-01, End date: 2023-02-28

Atmospheric aerosol particles impact Earth’s climate, by directly scattering sunlight and indirectly by affecting cloud properties. The largest uncertainties in climate change projections are associated with the atmospheric aerosol system that has been altered by anthropogenic activities. A major source of that uncertainty involves the formation of secondary particles and cloud condensation nuclei from natural and anthropogenic emissions of volatile compounds. This research challenge persists despite significant efforts within recent decades. I will build a research group that aims to resolve the atmospheric oxidation processes that convert volatile trace gases to particle precursor vapours, clusters and new aerosol particles. We will create novel measurement techniques and utilize the tremendous potential of mass spectrometry for detection of i) particle precursor vapours ii) oxidants, both conventional but also recently discovered stabilized Criegee intermediates, and, most importantly, iii) newly formed clusters. These methods and instrumentation will be applied for resolving the initial steps of new particle formation on molecular level from oxidation to clusters and stable aerosol particles. To reach these goals, targeted laboratory and field experiments together with long term field measurements will be performed employing the state-of-the-art instrumentation developed. Principal outcomes of this project include i) new experimental methods and techniques vital for atmospheric research and a deep understanding of ii) oxidation pathways producing aerosol particle precursors, iii) the initial molecular steps of new particle formation and iv) mechanisms of growth of freshly formed clusters toward larger sizes, particularly in the crucial size range of a few nanometers. The conceptual understanding obtained during this project will open multiple new research horizons from oxidation chemistry to Earth system modeling.

1 953 790 €

Start date: 2017-02-01, End date: 2022-01-31

State-of-the-art simulations and observations highlight the self-organization of convective clouds. Our recent work shows two aspects: these clouds are capable of unexpected increase in extreme precipitation when temperature rises; interactions between clouds produce the extremes. As clouds interact, they organize in space and carry a memory of past interaction and precipitation events. This evidence reveals a severe shortcoming of the conventional separation into "forcing" and "feedback" in climate model parameterizations, namely that the "feedback" develops a dynamics of its own, thus driving the extremes. The major scientific challenge tackled in INTERACTION is to make a ground-breaking departure from the established paradigm of "quasi-equilibrium" and instantaneous convective adjustment, traditionally used for parameterization of "sub-grid-scale processes" in general circulation models. To capture convective self-organization and extremes, the out-of-equilibrium cloud field must be described. In INTERACTION, I will produce a conceptual model for the out-of-equilibrium system of interacting clouds. Once triggered, clouds precipitate on a short timescale, but then relax in a "recovery" state where further precipitation is suppressed. Interaction with the surroundings occurs through cold pool outflow,facilitating the onset of new events in the wake. I will perform tailored numerical experiments using cutting-edge large-eddy simulations and very-high-resolution observational analysis to determine the effective interactions in the cloud system. Going beyond traditional forcing-and-feedback descriptions, I emphasize gradual self-organization with explicit temperature dependence. The list of key variables of atmospheric water vapor, temperature and precipitation must therefore be amended by variables describing organization. Capturing the self-organization of convection is essential for understanding of the risk of precipitation extremes today and in a future climate.

1 314 800 €

Start date: 2018-07-01, End date: 2023-06-30