Work

Eastward displacement of the Pacific–Japan pattern weakens its influence on summertime tropical cyclones affecting China

Year: 2026

Type: article

Abstract: Tropical cyclones (TCs) affecting China pose a major threat to coastal populations and economies, yet the large-scale climate controls on these TCs may vary over time. Here, we show that the influence of the Pacific–Japan (PJ) pattern on summertime (June–August) TCs affecting China has weakened markedly since the early-2000s. During 1979–2002, positive PJ phases were associated with significantly more TCs affecting China than negative phases, whereas this contrast largely disappeared during 2003–2025. This weakening primarily resulted from an eastward displacement of the PJ pattern and the associated circulation anomalies during summer. Before the early-2000s, the positive PJ phase enhanced TC genesis over the South China Sea and Philippine Sea, accompanied by easterly steering flow that favored westward propagation toward China. After the early-2000s, the PJ-related TC genesis enhancement became concentrated farther east over the western North Pacific, substantially weakening the PJ modulation of TCs in regions closer to China. Meanwhile, the PJ-related steering flow became less favorable for westward TC propagation toward China. These findings demonstrate that interdecadal shifts in the spatial structure of climate modes can fundamentally alter established climate–hazard relationships and reshape regional TC risk.

Source: Environmental Research Letters

DOI: 10.1088/1748-9326/aeb55c