EGU21-8926
https://doi.org/10.5194/egusphere-egu21-8926
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Future changes in North Atlantic winter cyclones in CESM-LENS: cyclone intensity and horizontal wind speed

Edgar Dolores Tesillos1, Stephan Pfahl2, and Franziska Teubler3
Edgar Dolores Tesillos et al.
  • 1Freie Universität Berlin, Institut für Meteorologie, Germany (edgar.dolores@met.fu-berlin.de)
  • 2Freie Universität Berlin, Institut für Meteorologie, Germany (stephan.pfahl@met.fu-berlin.de)
  • 3Johannes Gutenberg-Universität Mainz, Mainz, Germany (f.teubler@uni-mainz.de)

Strong low-level winds are among the most impactful effects of extratropical cyclones on society.  The wind intensity and the spatial distribution of wind maxima may change in a warming climate, however, the dynamics involved are not clear. Here, structural and dynamical changes of North Atlantic cyclones in a warmer climate close to the end of the current century are investigated with storm-relative composites based on Community Earth System Model Large Ensemble (CESM-LE) simulations. Furthermore, a piecewise potential vorticity inversion is applied, to attribute such changes in low-level winds to changes in PV anomalies at different levels.

We identify an extended wind footprint southeast of the cyclone centre, where the wind speed tends to intensify in a warmer climate. Both an amplified low-level PV anomaly driven by enhanced diabatic heating and a dipole change in upper-level PV anomalies contribute to this wind intensification. On the contrary, wind changes associated with lower- and upper-level PV anomalies mostly compensate each other upstream of the cyclone center. Wind changes at upper levels are dominated by changes in upper-level PV anomalies and the background flow. All together, our results indicate that a complex interation of enhanced diabatic heating and altered upper-tropospheric wave dynamics shape future changes in near-surface winds in North Atlantic cyclones.

How to cite: Dolores Tesillos, E., Pfahl, S., and Teubler, F.: Future changes in North Atlantic winter cyclones in CESM-LENS: cyclone intensity and horizontal wind speed, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8926, https://doi.org/10.5194/egusphere-egu21-8926, 2021.

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