Wintertime precipitation in eastern China and relation to the Madden-Julian oscillation: Spatiotemporal properties, impacts and causes

This study investigated the characteristics of wintertime precipitation in eastern China and associated atmospheric circulation based on different Madden-Julian oscillation (MJO) activities. Besides, the underlying causes and impacts of MJO activities on wintertime precipitation in eastern China were explored as well by analyzing large scale atmospheric circulations conditions. The results indicated that: (1) in different MJO phases, distinct differences can be observed in spatial patterns of wintertime precipitation in eastern China, especially in southeastern China. (2) Significant enhanced precipitation can be detected over southeastern China during active MJO events, while precipitation reduced significantly over these regions during inactive MJO events. Enhancement of precipitation during active MJO events was mainly attributed to the increased precipitation on phases 2-4; (3) the impacts of MJO phases on precipitation can be explained by the northeastward propagation of atmospheric pressure pattern over eastern China during active MJO events. This study may provide theoretical knowledge for water resources management and early warning of floods and droughts in eastern China. The potential teleconnections of near-equatorial MJO activities to the subtropics or extratropics precipitation over eastern China were also discussed in this study.