Projected near-surface wind speed based on CMIP6 GCMs

Understanding the future changes in global terrestrial near-surface wind speed (NSWS) at specific global warming levels (GWLs) is essential for climate change adaptation. Previous studies have projected NSWS changes, but the changes with different GWLs have yet to be studied. In this paper, we use the Max Planck Institute Earth System Model large ensembles to evaluate the contributions of different GWLs to NSWS changes.

Our results show that NSWS decreases over the Northern Hemisphere (NH) mid-to-high latitudes and increases over the Southern Hemisphere (SH) as GWL increases by 1.5◦C–4.0◦C relative to the preindustrial period, and that these characteristics are more significant with stronger GWLs. The probability density of NSWS shifts toward weak winds over NH and strong winds over SH between the current climate and the 4.0◦C GWL. Compared to the 1.5◦C GWL, NSWS decreases −0.066m s−1 over NH and increases +0.065m s−1 over SH with 4.0◦C GWL, with the decrease and increase being most significant in East Asia and South America, reaching −0.21 and +0.093m s−1, respectively.

The changes in temperature gradient induced by global warming could be the primary factor causing the interhemispheric asymmetry of future NSWS changes. Intensified global warming induces the reduction of Hadley, Ferrell, and Polar cells over NH, and the strengthening of the Hadley cell over SH could be another determinant of asymmetry changes in NSWS between two hemispheres.

Our study highlights the importance of considering different GWLs when projecting future NSWS changes. It also provides valuable insights into how the changes in temperature gradient and atmospheric circulation induced by global warming affect NSWS changes differently in the two hemispheres, which has important implications for climate change adaptation and mitigation strategies. The results of this study will contribute to a better understanding of the impacts of global warming on wind resources and wind energy production.