Dorothee Vallot
Ph.D.
Dorothee Vallot
Contact and CV
- Email: dorothee.vallot@smhi.se
- Phone: +46 11-495 80 00
- Dorothee Vallot, CV_Dorothee_Vallot (91 kB, pdf) pdf, 90.8 kB.
Publications
Fields of work
I am a Postdoctoral researcher (VR International Postdoc funding) based at SMHI but I spend part of my time at Université Grenoble Alpes, France and at St Andrews University, UK.
The aim of my research project is to understand the processes involved at the ocean-ice interface of Thwaites glacier, West Antarctica. I am particularly interested in the interactions between basal roughness under the ice shelf and the melt/freezing processes induced by the ocean. The final goal is to reduce uncertainties in ice shelf modelling, particularly threatened by climate change.
I use a series of models, at different time and spatial scales: the continuum ice flow model Elmer/Ice, the discrete particle model HiDEM, the ocean models NEMO (basin-scale model) and Firedrake (crevasse-scale). I am part of the International Thwaites Glacier Collaboration (ITGC) in the DOMINOS team (www.thwaitesglacier.org).
Research interests
Ocean-ice interactions at the vicinity of glaciers/ice shelves
Past experience
I defended my PhD in Glaciology at Uppsala University in 2018: Modelling calving and sliding of Svalbard outlet glaciers – Spatio-temporal changes and interactions External link.
Between 2018 and 2020, I worked for SMHI at the professional services department to provide hydrological methods and applications to diverse users.
Effects of subgrid-scale ice topography on the ice shelf basal melting simulated in NEMO-4.2.0
Dorothée Vallot, Nicolas C Jourdain, Pierre Mathiot
Oceanografisk klimatpåverkan på undervattensverksamhet i Östersjön och Västerhavet
Dorothée Vallot, Magnus Hieronymus, Lars Axell
In: Oceanografi
2025
Abstract
In this report, we examine how the oceanographic climate of the Baltic Sea and the Skagerrak–Kattegat region is expected to change and impact the sound speed in the future for two time periods, 2040–2050 and 2090–2099, compared with 2015–2024. The speed of sound in se-awater is primarily determined by three physical variables: temperature, salinity, and pressure. Because these parameters vary between marine environments, sound speed is not homogene-ous in the ocean. Changes in these variables with depth create complex vertical profles that infuence how sound propagates. To model temperature and salinity, we use NEMO-Nordic, a high-resolution ocean model for the Baltic Sea, the North Sea, and the English Channel, based on the internationally developed NEMO system. The model is forced with atmospheric data from three climate models (EC-Earth, HadGEM, and MPI) under three CMIP5 scenarios (RCP2.6, RCP4.5, and RCP8.5), resulting in three model members for each scenario. The sound-speed profles show clear seasonal inversions, with temperature — and thus sound speed — being lowest at the surface in winter and highest in summer. In all scenarios, sound speed increases over time, while salinity decreases, especially under RCP8.5, mainly due to an intensifed hydrological cycle. However, future salinity levels in the Baltic Sea are highly uncertain. The trends are similar in the Skagerrak–Kattegat region and the Baltic Sea, but the changes appear earlier in the Baltic Sea (from around 2040) and intensify toward the end of the century, particularly in RCP8.5.