– how the Fjord system works as a whole to transport water, organisms and ideas from one end to the other

An important project for the team Water and Water Systems is the interdisciplinary project The PLUME.

The project starts in June 2026 and has one postdoctoral position and two PhD positions associated with it:

Announcements with applications deadlines 10 May, 25 May and 1 June

• Project manager: Mats Ehrnstrøm, Department of Mathematical Sciences
• Deputy chairman: Terje Finstad, Department of Interdisciplinary Studies of Culture

Other project partners /participants:

• Professor Knut Tore Alfredsen, Department of Civil and Environmental Engineering
• Professor Hans Bihs, Department of Civil and Environmental Engineering
• Professor David Weissbrodt, Department of Biology
• Associate Professor Pauliina Salmi, Department of Biology
• Professor Daniel Beat Müller, Department of Energy and Process Engineering
• Researcher Sara Heidenreich, Department of Interdisciplinary Studies of Culture
• Postdoctoral Researcher Adrian Kirkeby, SIMULA

The Trondheim Fjord system consists of a complexity of rivers, streams and water catchments that feed the main fjord basin: the Trondheim Fjord. The fjord in this way receives substantial freshwater inflow into a topographically complex pool of stratified water with winds, currents, and a biological–ecological life cycle.

To picture this, envision a plume:

a burst of fast-running eutrophic freshwater that in a release meets the saline fjord water and flows out in typical plume-like pattern; see how circulation and transport evolve; and how nutrients, algae, and contaminants sink and flow along to distribute across layers and stages.

The water itself affects, and is affected by, the existing stratification, tides and currents; thematerial is sunk, or carried with the currents, to further influence the fjord itself: the viscosity and salinity, the temperature and vorticity, the visual depth and eutrophication, and finally the life cycles and the topography of the fjord itself.

A key knowledge gap in the scientific and environmental governance of the fjord is an integrated modelling system spanning both catchments/rivers and the fjord; this proposal advances such a system and, in parallel, examines how fjord models shape policy and public understanding – and how policies feed back on what is monitored and modelled.

The PLUME constitutes a Platform for a Land-to-fjord Unified Modelling Environment. It describes the plume as created by humans; the plume as a transportation process; and the plume as an environmental impact, in the three work packages:

• WP1 Water Dynamics
• WP2 Nutrient Impacts
• WP3 Societal Interactions

Illustration: WP1 Water Dynamics, WP2 Nutrient Impacs, WP3 Societal Interactions

Ilustration: Implementation