Reconstruction of conceptual prediction model for the Three Rainfall Patterns in the summer of eastern China under global warming.

With the influence of global warming, the global climate has undergone significant inter-decadal variation since the late 1970s. Although El Niño-Southern Oscillation (ENSO) has been the strongest signal for predicting global climate inter-annual variability, its relation with the summer rainfall in China has significantly changed, and its indicative function on the summer rainfall in China has weakened. This has led to a significant decrease in the accuracy rate of early conceptual prediction models for the Three Rainfall Patterns in the summer of eastern China. On the basis of the difference analysis of atmospheric circulation system configuration in summer, as well as the interaction of ocean and atmospheric in previous winter between two phases, i.e. before and after the significant global warming (1951 to 1978 and 1979 to 2012, respectively), we concluded that (1) Under different inter-decadal backgrounds, the atmospheric circulations that impacted the Three Rainfall Patterns in the summer of eastern China showed consistency, but in the latter phase of the global warming, the Western Pacific Subtropical High (WPSH) was on the strong side, the position of which was in the south, and the blocking high in the Eurasia mid-high latitudes was active, while the polar vortex extended to the south, and meridional circulation intensified. This circulation background may have been conducive to the increase of the circulation frequency of Patterns II and III, and the decrease of the circulation frequency of Pattern I, thus leading to more Patterns II and III and fewer Pattern I in the summer rainfall of eastern China. (2) In the former phase, the corresponding previous winter SST fields of different rainfall patterns showed visible differences. The impact of ENSO on North Pacific Oscillation (NPO) was great, and the identification ability of which on Patterns I and II of summer rainfall was effective. In the latter phase, this identification ability decreased, while the impact of ENSO on the Pacific/North American (PNA) teleconnection pattern increased, and the identification ability of the PNA on Patterns II and III also increased. Based on the new inter-decadal climate background, this study reconstructs the conceptual prediction model for the Three Rainfall Patterns in summer of eastern China by using the previous winter PNA and the Eurasian (EU) teleconnection indexes. The fitting effect was satisfying, though it is necessary to be further tested. [ABSTRACT FROM AUTHOR]