Effects of Northern Hemisphere Annular Mode on terrestrial near-surface wind speed over eastern China from 1979 to 2017

Large-scale ocean‒atmosphere circulations (LOACs) have a pronounced effect on the near-surface wind speed (NSWS). In this study, we discussed contributions of zonal and meridional flows to NSWS changes identify possible association between Northern Hemisphere Annular Mode (NAM) over eastern China from 1979 2017. Results show that reduction in was mainly dominated by weakening component. NAM has considerable China. When exhibits positive phases, zonal-mean westerly weakens at low-to-mid-latitudes (10°–40°N). Meanwhile, descending prevail near 40°N, ascending persist 65°N troposphere. lower troposphere, there are northerly anomalies southerly mid-to-high latitudes (40°–70°N). The anomalous transport heat low high weaken north‒south air temperature gradient. decreased gradient East Asia reduces pressure surface, decreasing variations could dominate (32.0 ± 15.8)% annual mean NSWS. Nevertheless, contribution interannual component reach (45.0 12.9)%.