ERC FUNDED PROJECTS

"Atmospheric aerosol particles have been shown to impact the earth's climate because they scatter and absorb solar radiation (direct effect) and because they can modify the microphysical properties of clouds by acting as cloud condensation nuclei or ice nuclei (indirect effects). Radiative forcing by anthropogenic aerosols remains poorly quantified, thus leading to considerable uncertainty in our understanding of the earth’s climate response to the radiative forcing by greenhouse gases. Black carbon (BC), mostly emitted by anthropogenic combustion processes and biomass burning, is an important component of atmospheric aerosols. Estimates show that BC may be the second strongest contributor (after CO2) to global warming. Adverse health effects due to particulate air pollution have also been associated with traffic-related BC particles. These climate and health effects brought BC emission reductions into the political focus of possible mitigation strategies with immediate and multiple benefits for human well-being. Laboratory experiments aim at the physical and chemical characterisation of BC emissions from diesel engines and biomass burning under controlled conditions. A mobile laboratory equipped with state-of-the-art aerosol sensors will be used to determine the contribution of different BC sources to atmospheric BC loadings, and to investigate the evolution of the relevant BC properties with atmospheric aging during transport from sources to remote areas. The interactions of BC particles with clouds as a function of BC properties will be investigated with in-situ measurements by operating quantitative single particle instruments behind a novel sampling inlet, which makes selective sampling of interstitial, cloud droplet residual or ice crystal residual particles possible. Above experimental studies aim at improving our understanding of BC’s atmospheric life cycle and will be used in model simulations for quantitatively assessing the atmospheric impacts of BC."

1 992 015 €

Start date: 2014-03-01, End date: 2019-02-28

"Land-climate interactions mediated through soil moisture and vegetation play a critical role in the climate system, in particular for the occurrence of extreme events such as droughts and heatwaves. They are, however, poorly constrained in current Earth System Models (ESMs), leading to large uncertainties in climate projections. These uncertainties affect the quality and accuracy of projections of temperature, water availability, and carbon concentrations, as well as that of projected impacts on agriculture, ecosystems, and health. In the past years, in-situ and remote sensing-based datasets of soil moisture, evapotranspiration, and energy and carbon fluxes have become increasingly available, providing untapped potential for reducing associated uncertainties in current climate models. The DROUGHT-HEAT project aims at innovatively exploiting these new information sources in order to 1) derive observations-based diagnostics to quantify and isolate the role of land-climate interactions in past extreme events (""Diagnostic Atlas""), 2) evaluate and improve current ESMs and constrain climate-change projections using the derived diagnostics, and 3) apply the newly gained knowledge to frontier developments in the attribution of climate extremes to land processes and their mitigation through ""land geoengineering"". The DROUGHT-HEAT project integrates the newest land observational datasets with the latest stream of ESMs. Novel methodologies will be applied to extract functional relationships from the data, and identify key gaps in the ESMs' representation of underlying processes. These will build on physically-based relationships, machine learning tools, and model calibration. In addition, they will encompass the mapping and merging of derived diagnostics in space and time to reduce ""blank spaces"" in the datasets. The project is unprecedented in its breadth and scope and will allow a major breakthrough in our understanding of the processes leading to heatwaves and droughts."

1 952 285 €

Start date: 2014-09-01, End date: 2019-08-31

"Tectonic plate corners are hotspots for high rates of continental deformation and erosion, and associated with human-relevant hazards including poorly understood earthquakes, destructive landslides, and extreme climate. A better understanding of continental deformation can mitigate these hazards. However, the coupling between climate and tectonic interactions at plate corners is a key unknown and the focus of this study. My recent work, published in international journals including Science and Nature, quantifies mountain building and climate change and provides a baseline for an innovative study of plate corner dynamics. This proposal challenges the geoscience ‘tectonic aneurysm’ paradigm that rapid deformation and erosion at plate corners is initiated from the “top down” by localized precipitation, and erosion. Rather, I hypothesize that these processes are: 1) initiated from the “bottom up” by the 3D geometry of the subducting plate; and 2) require a threshold rate of both “bottom up” deformation and surface erosion to initiate a feedback between climate and tectonics. I propose, for the first time, a holistic modeling and data collection approach that quantifies the temporal and spatial evolution of all aspects of plate corner evolution, including: 3D thermomechanical modeling of plate corner deformation and uplift for different plate geometries; Atmospheric modeling to quantify the climate response to evolving topography, a topic spearheaded by my research group; And surface process modeling to close the loop and couple the atmospheric and mechanical models. Model predictions will be vetted against observed deformation and erosion histories from existing and new cosmogenic isotope and thermochronometer data from end-member locations including the Himalaya, Alaskan, Olympic, and Andean plate corners. EXTREME will produce a globally integrated atmospheric and solid Earth understanding of continental deformation, a task only possible at the scale of an ERC grant."

1 999 956 €

Start date: 2014-04-01, End date: 2019-03-31

This proposal aims to develop new isotopic tools designed to constrain the core formation process in the Earth. We will use isotopic fractionations imparted by metal-silicate equilibration during core formation to obtain new and firm constraints on (i) the physical and chemical processes during formation of the Earth's core; and (ii) on the origin of volatile elements and the volatile accretion history of the Earth. The underlying concept of our approach is to compare observed mantle-core isotopic fractionations (determined on natural samples) to the experimentally-determined isotope fractionation between liquid metal (core analogue) and liquid silicate (mantle analogue). Since the magnitude of isotope fractionation is strongly temperature-dependent, this comparison will enable us to evaluate core formation temperatures. I propose to use the stable isotope systematics of W, Mo and Cr to assess as to whether core formation temperatures for the Earth, Moon, Mars and asteroids are different, as would be expected if metal segregation in the Earth involved metal-silicate equilibration in a deep magma ocean. If instead all bodies have similar core formation temperatures, then formation of the Earth's core most probably involved some disequilibrium induced by direct core mergers during accretion from differentiated bodies. The second major theme of the proposed research uses Ge and Sb stable isotopes to trace the origins of Earth's volatiles. The combined investigation of Ge and Sb isotope fractionations in natural samples and metal-silicate equilibration experiments will enable us to determine as to whether Ge and Sb, and with them other volatile elements, show an isotope signature resulting from core formation. Identifying such a signature would provide the unequivocal evidence that volatile elements were delivered to the Earth during core formation and not subsequently, after the core had formed.

1 940 040 €

Start date: 2014-02-01, End date: 2019-10-31