Hiring Institution
Université Grenoble Alpes (UGA)

PhD-Awarding Institutions
Université Grenoble Alpes (UGA)
University of Tasmania (UTAS)

Download full Position Description in PDF

Option 1

Surface mass balance of the Antarctic Megadune plateau

Antarctica holds 27 million km3 of snow and ice that can affect sea level, ocean circulation, and weather patterns. Despite its importance, we lack basic knowledge on snow accumulation in Antarctica, such as how much is accumulating and how it varies over time and space, limiting our capacity to predict the sea level rise. In an attempt to answer these questions multiple ice cores have been drilled in the East Antarctic ice sheet through the East Antarctic International Traverse (EAIIST) projects. These cores come from a previously unsampled region of Antarctica known as the Megadunes for its unusual topography driven by an extreme environment of arid, wind and cold. They are presently stored in France, Italy and Australia.
Using volcanic horizons as time markers, coupled with ground penetrating radar (GPR) measurements, we propose to reconstruct the surface mass balance (SMB) of the Megadune plateau, both in time and space. To achieve this goal, the candidate will perform laboratory sampling and analysis of the raw geochemical data of the different ice cores, with capacity of stable isotope and electron microprobe analysis for unambiguous tie-point identification. In a second step, the candidate will treat the GPR data to reveal internal layers of the snow pack. Matching radar internal layers with well-dated ice core reference layers (e.g. volcanic layers) will allow to date and deduce the surface mass balance through time for the full EAIIST transect. The variability of the SMB observed will finally be studied in the context of past and current climate changes.
In addition to the data processing work (IGE), the student will gain expertise in advanced analytical techniques including separative techniques (IGE & AAD) and ultra-high-resolution mass spectrometer (ThermoFisher & IGE).
The candidate must have (or acquire) the basics of chemical analysis, an interest in environmental issues, and good skills to work in a team as well as independently. Proficiency in programming (R, Python) for data management and statistical analyses will also be required.”

Option 2

Spatial variability of signals in ice coring at low accumulation sites

One of the most unresolved questions in ice core science is the local-scale spatial variability and its influence on the robustness of the signals recorded in ice and air bubbles. This variability is exacerbated at low accumulation sites precisely where the deep ice cores are generally drilled. Recent studies have emphasized the need to better consider spatial variability at the local scale. For instance, current volcanic reconstructions based on ice core analysis have significantly improved over the past few decades by incorporating multiple-core analyses with a high temporal resolution from different parts of the Polar Regions into a composite common volcanic eruption record. However, in many cases only single records at given sites are used for these reconstructions and past studies have found that local-scale variability, essentially attributed to snow drift and surface roughness, could lead to a non-exhaustive record of volcanic events when a single core is used as the site reference.
Following the success of the East Antarctic International Traverse (EAIIST) that took place in 2020, we have drilled 20 cores over a large area of the East Antarctic Plateau. This ice database, shared between Italy, France and Australia is the perfect tool to establish the spatial signal-to-noise ratio of different ice proxy markers.
In a common endeavor, we propose to carry out a spatial survey of the geochemical signals trapped in ice cores. Such “signal” could concern volcanic events recorded in the ice, nitrogen and sulfur stable isotope fingerprinting, sea-salt or halogen compounds. The goal first is to extract from this ice core database the signal-to-noise ratio and deduce the regional signal information through statistical analysis. In a second step, this regional information will be compared to other deep inland or coastal cores (e.g. EPICA, Law Dome Talos Dome, Mont Brown South, etc.) to reveal common and disparity between these cores and what could be the biases in the deep core records when only a single core is available.
As for the position 1, in addition to the data processing work (IGE), the student will gain expertise in advanced analytical techniques including separative techniques (IGE & AAD) and ultra-high-resolution mass spectrometer (ThermoFisher & IGE).
The candidate must have (or acquire) the basics of chemical analysis, an interest in environmental issues, and good skills to work in a team as well as independently. Proficiency in programming (R, Python) for data management and statistical analyses will also be required.”

Option 3

Variability of aerosol deposition in ice cores from coastal and interior locations in East Antarctica

Ice core records of aerosol trace chemicals, cosmogenic isotopes and dust are used to produce multi-proxy records of past climate and to infer the origin of air-masses. The mechanism through which sea salt aerosols are deposited changes from wet, cyclonic precipitation in coastal areas to dry, “”diamond dust”” deposition inland.
The sea salt records from new cores from the EAIIST traverse using high resolution CFA techniques will complement other records such as from Law Dome, Mount Brown South and Aurora Basin North, to study of the changes in the depositional regimes spatially.
This project will compare sea salt aerosols and volcanic sulfate records in these ice cores to study how the dominant type of deposition mechanism, and hence snow accumulation patterns vary in ice cores from the Antarctic coast to the interior. The second part of this project will use this to inform how the snow accumulation regimes may have changed within glacial-interglacial cycles with changing ice sheet extent causing sites to become more coastal or inland over time.
As for the position 1, in addition to the data processing work (IGE), the student will gain expertise in advanced analytical techniques including separative techniques (IGE & AAD) and ultra-high-resolution mass spectrometer (ThermoFisher & IGE).
The candidate must have (or acquire) the basics of chemical analysis, an interest in environmental issues, and good skills to work in a team as well as independently. Proficiency in programming (R, Python) for data management and statistical analyses will also be required.”

Joel Savarino
Lenneke Jong

Environmental Geosciences, Paleoclimate, Ice Core Chemistry