Rainfall seasonality changes and its possible teleconnections with global climate events in China

Abstract

Despite the importance of seasonal distribution and interannual variability of rainfall to the ecosystem and society, there is a lack of regional-level studies on rainfall seasonality, and teleconnections between global climate events and rainfall seasonality are not well understood. To address these issues, this study analyzed the spatial and temporal characteristics of rainfall seasonality across China from 1961 to 2012. A novel application of information theory-based rainfall seasonality indicators was conducted at the regional scale, and observed monthly precipitation data was used. The rainfall seasonality anomalies during negative and positive phases of the El Nino–Southern Oscillation, Indian Ocean Dipole, North Atlantic Oscillation, and Pacific Decadal Oscillation, and the possible physical mechanisms behind were also investigated. The results showed that rainfall seasonality increased, especially in Southeast China, which can be attributed to changes in magnitude (annual rainfall), timing, or duration of the wet season. Global climate events significantly affected rainfall seasonality indicators in Southeast China during negative and positive phases. The sea surface temperature (SST) or sea level pressure (SLP), and wind anomalies during the negative and positive phases might explain the spatial differences in the influences of global climate events on rainfall seasonality across China. These results may prove valuable for sustainable water resource management and agricultural production in China.