EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Characterising simulated changes of jet streams since the Last Glacial Maximum

Patrizia Schoch1, Jean-Philippe Baudouin1,2, Nils Weitzel1,2, Marie Kapsch3, Thomas Kleinen3, and Kira Rehfeld1,2,4
Patrizia Schoch et al.
  • 1Institut für Umweltphysik (IUP), Universität Heidelberg, INF229, 69120 Heidelberg, Germany
  • 2Geo- und Umweltforschungszentrum (GUZ), Universität Tübingen, Schnarrenbergstr. 94-96, 72076 Tübingen, Germany
  • 3Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany
  • 4Department of Physics and Department of Geoscience, Tübingen University, Tübingen, Germany

Jet streams control hydroclimate variability in the mid-latitudes with important impacts on water availability and human societies. According to future projections, global warming will change jet stream characteristics, including its mean position. Variability of these characteristics on hourly-to-daily timescales is key to understanding the mid-latitudes circulation. Therefore, most analysis methods of present-day jet streams are designed for 6-hourly data. By modelling the climate since the Last Glacial Maximum, we can investigate the long-term drivers of jet stream characteristics. However, for transient simulations of the last deglaciation, 3d wind fields are only archived with a monthly resolution due to storage limitations. Hence, jet variability at shorter timescales cannot be identified, and established methods can’t be used.

Here, we study to what extent changes of jet stream characteristics can be inferred from monthly wind fields. Therefore, we compare latitudinal jet stream positions, strength, tilt and their variability from daily and monthly wind fields in reanalysis data and for LGM and PI simulations. We test three different methods to construct jet stream typologies and metrics. This comparison identifies to which extend these jet stream characteristics can be robustly studied from monthly wind fields. In addition, our analysis assesses the added value of archived daily data for future research. Once the limitations of monthly wind output are known, jet stream characteristics in transient simulations of the last deglaciation can be analysed. This analysis provides new insights on jet stream changes on decadal-to-orbital timescales and identifies the factors controlling these changes.

How to cite: Schoch, P., Baudouin, J.-P., Weitzel, N., Kapsch, M., Kleinen, T., and Rehfeld, K.: Characterising simulated changes of jet streams since the Last Glacial Maximum, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5069,, 2022.

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