EGU2020-1723, updated on 20 Jan 2021
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

A Dynamical Systems Characterisation of Atmospheric Jet Regimes in a Simple Model and Reanalysis Data

Nili Harnik1, Gabriele Messori2,6, Erica Madonna3, Orly Lachmy4, and Davide Farranda5,7
Nili Harnik et al.
  • 1Tel Aviv University, Geophysics department, School of the Environment and Earth Sciences, Israel (
  • 2Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
  • 3Bjerknes Centre for Climate Research, Bergen, Norway
  • 4Department of Natural Sciences, Open University of Israel, Ra'anana, Israel
  • 5Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France.
  • 6Department of Meteorology and Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
  • 7London Mathematical Laboratory, London, U. K

Atmospheric jet streams are typically separated into primarily "eddy-driven", or "polar-front" jets and primarily "thermally-driven", or "subtropical" jets. Some regions also display “merged” jets, resulting from the (quasi) co-location of the regions of eddy generation with the subtropical jet. The different location and driving mechanisms of the two jet structures, plus the intermediate “merged” jet, issue from very different underlying mechanisms, and result in very different jet characteristics. Here, we link our understanding of the dynamical jet maintenance mechanisms, mostly issuing from conceptual or idealised models, to the phenomena observed in reanalysis data. We specifically focus on developing a unitary analysis framework, grounded in dynamical systems theory, which may be applied to both the model and reanalysis data and allow for direct intercomparison. Our results provide a proof-of-concept for using dynamical systems indicators to diagnose jet regimes in a versatile, conceptually intuitive and computationally efficient fashion.

How to cite: Harnik, N., Messori, G., Madonna, E., Lachmy, O., and Farranda, D.: A Dynamical Systems Characterisation of Atmospheric Jet Regimes in a Simple Model and Reanalysis Data, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1723,, 2019


Display file

Comments on the display

AC: Author Comment | CC: Community Comment | Report abuse

displays version 1 – uploaded on 28 Apr 2020
  • CC1: Comment on EGU2020-1723, Swinda Falkena, 05 May 2020

    Hi Gabriele,

    Thank you for the interesting display and brief introduction in the chat. You show some results for reanalysis for the Southern Hemisphere. Have you also looked at the Northern Hemisphere?

    Best wishes,


    • AC1: Reply to CC1, Gabriele Messori, 05 May 2020

      Hi Swinda, thank you for your interest in our work! We haven't looked at the NH as, so far, we have simply used reanalysis as a reality check for the analysis we built using an idealised 2-layer model. However, a more systematic look at "real" data is definitely in the books!


      • CC2: Reply to AC1, Swinda Falkena, 05 May 2020


        Hi Gabriele,

        Thank you! I'd definitely be interested if you have some results on the NH, really interesting work. I'll keep an eye out for it.