Preprints
https://doi.org/10.5194/wcd-2021-73
https://doi.org/10.5194/wcd-2021-73

  08 Nov 2021

08 Nov 2021

Review status: this preprint is currently under review for the journal WCD.

Future changes in North Atlantic winter cyclones in CESM-LENS. Part I: cyclone intensity, PV anomalies and horizontal wind speed

Edgar Dolores-Tesillos1, Franziska Teubler2, and Stephan Pfahl1 Edgar Dolores-Tesillos et al.
  • 1Institute of Meteorology, Freie Universität Berlin, Berlin, Germany
  • 2Johannes Gutenberg-Universität Mainz, Mainz, Germany

Abstract. Strong low-level winds associated with extratropical cyclones can cause substantial impacts on society. The wind intensity and the spatial distribution of wind maxima may change in a warming climate; however, the involved changes in cyclone structure and dynamics are unclear. Here, such structural changes of strong 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-LENS) simulations. Furthermore, a piecewise potential vorticity inversion is applied to associate such changes in low-level winds to changes in potential vorticity (PV) anomalies at different levels. Projected changes in cyclone intensity are generally rather small. However, using cyclone-relative composites, we identify an extended wind footprint southeast of the center of strong cyclones, 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 interaction of enhanced diabatic heating and altered non-linear upper-tropospheric wave dynamics shape future changes in near-surface winds in North Atlantic cyclones.

Edgar Dolores-Tesillos et al.

Status: open (until 20 Dec 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Edgar Dolores-Tesillos et al.

Edgar Dolores-Tesillos et al.

Viewed

Total article views: 263 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
176 82 5 263 27 4 2
  • HTML: 176
  • PDF: 82
  • XML: 5
  • Total: 263
  • Supplement: 27
  • BibTeX: 4
  • EndNote: 2
Views and downloads (calculated since 08 Nov 2021)
Cumulative views and downloads (calculated since 08 Nov 2021)

Viewed (geographical distribution)

Total article views: 263 (including HTML, PDF, and XML) Thereof 263 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 27 Nov 2021
Download
Short summary
Strong winds caused by extratropical cyclones represent a costly hazard for European countries. Here, based on CESM-LENS coupled climate simulations, we show that future changes of such strong winds are characterized by an increased magnitude and extended footprint southeast of the cyclone center. This intensification is related to a combination of increased diabatic heating and changes in upper-level wave dynamics.