Stockholm university
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Research project Oceanic and Atmospheric Overturning Circulation

By studying the oceanic and atmospheric overturning circulation it is possible to for example track the heat, salt and moisture exchanges between the low and high latitudes.

Graf depicting global air-mass overturning strem functions. Image: K.Döös/MISU/Stockholm University
FIG. 1. The global air-mass overturning stream function for the atmosphere (top panel) and global water-mass overturning stream function for the ocean (bottom panel) simulated by an Earth System model. Arrows indicate the mass transport direction. All transports are in Sv (109kg/s). Image: K.Döös/MISU/Stockholm University
Graph depicting Atmospheric water trajectories. Image: K.Döös/MISU/Stockholm University
FIG. 2a. Conventional longitude-latitude map. Atmospheric water trajectories started at the sea surface at evaporation points and ended at the surface at precipitation points. Note that these are water trajectories not air trajectories simulated by TRACMASS with a new water mass conservation method. Image: K.Döös/MISU/Stockholm University
Graph depicting Atmospheric water trajectories. Image: K.Döös/MISU/Stockholm University
FIG. 2b. Trajectories in the temperature-humidity space, an alternative way to describe the overturning. Atmospheric water trajectories started at the sea surface at evaporation points and ended at the surface at precipitation points. Note that these are water trajectories not air trajectories simulated by TRACMASS with a new water mass conservation method. Image: K.Döös/MISU/Stockholm University

Figure 1 shows how this is viewed by cells, which transport water and air in the coupled ocean-atmosphere system simulated with the Earth system model EC-Earth.

An alternative way to study the overturning circulation is with Lagrangian trajectories, which makes it possible to follow a given water or air mass from a given region to another. For this we have developed the trajectory model TRACMASS (www.tracmass.org) for both air masses and water masses.

In Figure 2a and 2b we have followed water in the atmosphere from evaporation regions in the Tropical Pacific to the precipitation points.

Project description

 

Project title: Inter-ocean exchange of freshwater and heat through both the ocean and the atmosphere in a warmer climate.

Funded by: Swedish Research Council
Funding period: 2020-2024
Project ID: 2019-03574

 

Project members

Project managers

Kristofer Döös

Professor of Climate modeling

Department of Meteorology
08-16 17 34
073-913 16 51
Kristofer Döös
kristofer.doos@misu.su.se
See profile page for Kristofer Döös

Members

Aitor Aldama Campino

PhD

Formerly at the Department of Meteorology, Stockholm University

Dipanjan Dey

PhD

Formerly at the Department of Meteorology, Stockholm University

Joakim Kjellsson

PhD

Formerly at the Department of Meteorology, Stockholm University

Johan Nilsson

Professor of Meteorology

Department of Meteorology
08-16 17 36
me
johan.nilsson@misu.su.se
See profile page for Johan Nilsson

Jonas Nycander

Professor of Physical oceanography

Department of Meteorology
08-16 43 36
portrait of Jonas Nycander
jonas.nycander@misu.su.se
See profile page for Jonas Nycander

Sara Berglund

PhD

Formerly at the Department of Meteorology, Stockholm University

Verena Nadine Jung

PhD-student

Department of Meteorology
08-16 44 25
verena.jung@misu.su.se
See profile page for Verena Nadine Jung

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