中国气象学会气象青年科技交流会暨2022年青年科学家论坛

34 / 2022-03-04 17:22:13

Projection of future changes in global terrestrial near-surface wind speed and its uncertainty

Near-surface wind speed,CMIP6,1.5 and 3.0℃ global warming level,Large ensembles,future projections

Understanding future changes in global terrestrial near-surface wind speed (NSWS) in specific global warming level (GWL) is crucial for climate change adaption. Previous studies have projected the NSWS changes; however, the changes of NSWS with different GWLs have yet to be studied. In our study, we employ the Max Planck Institute Earth System Model large ensembles to evaluate the contributions of different GWLs to the NSWS changes. The results show that the NSWS decreases over the Northern Hemisphere (NH) mid-to-high latitudes and increases over the Southern Hemisphere (SH) as the GWL increases by 1.5–4.0 ℃ relative to the preindustrial period, and that

these characteristics are more significant with the stronger GWL. The probability density of the NSWS shifts toward weak winds over NH and strong winds over SH between the current climate and the 4.0 ℃ GWL. Compared to 1.5 ℃ GWL, the NSWS decreases -0.066 m s-1 over NH and increases +0.065 m s-1 over SH with the 4.0 ℃ GWL, especially for the East Asia and South America, the decrease and increase are most significant, which reach -0.21 and +0.093 m s-1, respectively. Changes in the 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 in 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.