During her PhD studies, Lou-Anne worked on the effect of pigment-producing microbes on snow and ice melt. Such microbes are ubiquitous at the surface of glacier and ice sheets and enhance melt by reducing the surface albedo. Lou-Anne Ambre researched how microbial darkening can be implemented in physical albedo models and developed new methods to quantify microbial darkening from remote sensing imagery. Lou-Anne then applied these methods to investigate the role of microbes in the darkening of the southwestern ice sheet of Kalaallit Nunaat (Greenland), as well as the seasonal snow cover in Southern Norway.

Lou-Anne’s work provides new tools to model and quantify microbial darkening in new study areas, and hence represents a significant step towards its global quantification and inclusion in regional climate models. 

The PhD study was completed at the Department of Environmental Sciences, Faculty of Technical Sciences, Aarhus University.

This summary was prepared by the PhD student.

Time: Wednesday 12 March 2025 at 13:00
Place: Building 112, HH Kock Auditorium, Aarhus University, Risø Campus, 399 Frederiksborgvej 4000 Roskilde
Title of PhD thesis: Signature and darkening effect of microbial life on snow and ice
Contact information: Lou-Anne Chevrollier, e-mail: lou.chevrollier@envs.au.dk
Members of the assessment committee:
Senior Researcher Marie Dumont, Centre d’Etudes de la Neige, Université Grenoble Alpes, Université de Toulouse, Météo-France, CNRS, CNRM, France
Professor Christine Schøtt Hvidberg, Niels Bohr Institute, Københavns Universitet, Denmark
Senior Researcher Niels Bohse Hendriksen (chair), Department of Environmental Sciences, Aarhus University, Denmark
Main supervisor:
Professor Martyn Tranter, Department of Environmental Sciences, Aarhus University, Denmark
Co-supervisor:
Lecturer Joseph Mitchell Cook, Department of Environmental Sciences, Aarhus University, Denmark
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Technical Sciences/GSTS, Ny Munkegade 120, building 1521, 8000 Aarhus C.