Abstract
Using composite, regular, and partial regression analyses in the six consecutive seasons from spring of the El Niño–Southern Oscillation (ENSO)-/Indian Ocean Dipole (IOD)-developing year through summer following the ENSO/IOD mature phase, the individual and combined impacts of El Niño and positive Indian Ocean Dipole (pIOD) on the evolution of precipitation in China are diagnosed for the period 1950–2013. It is shown that the seasonal responses of precipitation in China to El Niño and pIOD events, and their relationship with the large-scale atmospheric circulations, differ from one season to another. For the pure El Niño years, there is a seasonal reversal of precipitation over southeastern and northwestern China, with deficient precipitation occurring in these two regions before the onset of anomalous wet conditions in the developing autumn. Meanwhile, North China tends to be drier than normal in the developing seasons, but wetter than normal in the decaying seasons. For the pure pIOD events, southern China suffers a precipitation deficit (surplus) in the developing spring (summer and autumn). Furthermore, both North China and northwestern China experience excessive precipitation in the developing autumn and decaying summer. In addition, there is reduced precipitation in northeastern China during both the developing and decaying summers, whereas increased precipitation occurs in the developing autumn and decaying winter. For the combined years, southern China experiences enhanced moisture supply and suffers from increased precipitation from the developing summer through the subsequent spring, but reduced precipitation in the developing spring and decaying summer. Similar to the pure El Niño, northwestern (North) China becomes wetter than normal after the developing summer (autumn) in the combined years. In general, the ENSO/IOD-related precipitation variability could be explained by the associated anomaly circulations.
Highlights
China, the world’s most populated country [1], is characterized by a distinct continental monsoon climate and complex climate types
The precipitation anomalies associated with pure El Niño/positive Indian Ocean Dipole (pIOD) were assessed with partial regressions of precipitation onto partial Niño3.4 index/Dipole Mode Index (DMI) respectively, while those associated with combined events were computed with regular regressions
The results demonstrate that precipitation change in
Summary
The world’s most populated country [1], is characterized by a distinct continental monsoon climate and complex climate types. Xu et al [36] studied the possible cooperative impacts of combined ENSO and IOD events on boreal autumn rainfall anomalies in China. They have pointed out that the positive phase of the combined ENSO and IOD events may result in an increased autumn rainfall over southern China by an anomalous lower-level anticyclone over the western North Pacific (WNP) region. We build upon this earlier research, study the possible influences of the ENSO and IOD phenomena together with their combined influences on the evolution of precipitation in China throughout their phases, and explore the possible mechanisms underpinning these effects, based on their impact on water vapor flux. The principal novelty is that we examine the effects of ENSO and the IOD separately as well as together throughout their entire phases
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
