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Research

🔬 Keywords

Antarctica ⦁ Polar climate ⦁ Water isotopes

📌 Research Interests

🛠 Tools & Methods

Global Atmospheric Model LMDZ ⦁ Observations ⦁ Water stable isotopes ⦁ Reanalyses outputs ⦁ Global Climate Models outputs

My research focuses on the atmospheric water cycle in Antarctica, with a particular emphasis on water isotopes. To investigate this, I use the LMDZ6iso global atmospheric model to simulate isotope dynamics.

In Antarctica, the study of water isotopes in surface snow, precipitation, and vapour is conducted with a dual objectives: gaining a deeper understanding of isotopic signals archived in ice cores, and deciphering the contributions of different atmospheric processes in driving the water cycle, including boundary layer processes.

Atmospheric general circulation models (AGCMs) with water isotopes provide a crucial tool for simulating fractionation and transport processes. They allow us to investigate isotopic signatures across different timescales, from meteorological events to seasonal and interannual variations, as well as past climate reconstructions within a physically coherent framework.

Study 1: Antarctic Water Stable Isotopes in the Global Atmospheric Model LMDZ6: From Climatology to Boundary Layer Processes

During my PhD, my first study focuses on evaluating the LMDZ6iso global atmospheric model by comparaison with surface snow isotopes across Antarctica, as well as daily precipitation and continuous water vapor isotopes at two East Antarctic stations: Dumont d’Urville (coastal) and Concordia (inland). This evaluation examines spatial, seasonal, and diurnal isotopic variations in the model.

Next, I analyzed the contributions of individual processes to boundary layer water vapor isotopes, aiming to identify the key drivers of clear-sky isotopic daily cycles and to explain discrepancies between model simulations and observations.

🔹 At Concordia, daily isotope variations are mainly driven by surface sublimation.
🔹 At Dumont d’Urville, they are influenced by both surface sublimation and advection by the katabatic flow.

These results suggest that further improvements in LMDZ6iso should prioritize better representation of isotopic exchanges during sublimation and condensation under low temperatures.

Study 2: Water vapour isotope anomalies during an atmospheric river event at Dome C, East Antarctica (in preparation)

My second study focuses on analyzing the isotopic anomaly in water vapour induced by the passage of an atmospheric river over Concordia in December 2018. The isotopic composition of water vapour observed during this event can be explained by two key processes:

Using the LMDZ6iso simulation previously evaluated, we show that surface sublimation is the primary driver of the positive isotopic anomaly in vapour, contributing 60% of the total signal. This sublimation effect is significantly increase during the event compared to typical diurnal cycles. The remaining 40% of the anomaly is attributed to large-scale moisture advection associated with the atmospheric river.
These results highlight that the isotopic signal recorded in water vapor during atmospheric river events reflects a combination of long-range moisture advection and interactions between the boundary layer and the snowpack, reinforcing the importance of local surface processes in shaping Antarctic isotope variability.