Decadal shift in Northeast China’s precipitation around 2000

Northeast China (NEC), a critical agricultural and ecological zone, has experienced intensified hydrological variability under global warming, with cascading impacts on food security and ecosystem resilience. This study utilized observational data and two new generation reanalysis products (i.e., the fifth major global reanalysis produced by ECMWF (ERA5) and the Japanese Reanalysis for Three Quarters of a Century (JRA-3Q)) to investigate the shift changes in precipitation in NEC around 2000 and associated water vapor transport. Our analysis identified a pivotal interdecadal shift in 1998/99, transitioning from moderate increases (17.5 mm (10 yr) −1 during 1980–1998) to accelerated but more variable precipitation growth (85.4 mm (10 yr) −1 post-1999). While the mean precipitation during the post-shift period decreased, enhanced anticyclonic circulation amplified moisture divergence over continental NEC, redirecting vapor flux toward coastal regions. Crucially, trajectory analysis demonstrated regime-dependent moisture sourcing: midlatitude westerlies dominated during wet extremes (44% of trajectories in 1998), whereas East Asian monsoon flows prevailed in drought years (36% of trajectories in 2007). The post-1998 period exhibited increased reliance on localized recycling (45% of mid-tropospheric trajectories), reflecting weakened monsoonal inflow. These findings highlight NEC's growing vulnerability to competing moisture pathways and atmospheric blocking—a dual mechanism that explains rising extremes despite declining mean precipitation. By reconciling dataset discrepancies (ERA5 vs. JRA-3Q trends) and elucidating circulation-precipitation linkages, this work provides actionable insights for climate-resilient agriculture in NEC's water-stressed ecosystems. 东北地区作为中国重要的农业生态区之一, 在区域变暖背景下降水呈现显著波动.该论文基于CN05.1观测数据与ERA5,JRA-3Q再分析资料, 发现东北地区降水在1998/99年发生关键转折:降水量增速由前期的17.5 mm/10年 (1980-1998年) 跃升至85.4 mm/10年 (1999-2022年) .反气旋环流增强导致大陆区水汽辐散, 向沿海输送增加.轨迹分析显示水汽来源存在显著年际差异:1998年丰水期44%水汽源自西风带, 2007年旱季36%水汽来自东亚季风.