Global Rainstorm Temporal Variation from 1979 to 2016 Based on the Perspective of Land-Ocean Differentiation

Abstract

Based on the ERA-Interim precipitation data from 1979 to 2016, this paper uses a variety of statistical methods to diagnose the multi-attribute time series characteristics of global rainstorms and its response to ENSO from the perspective of land-ocean differentiation. The results showed as follows. (1) The global, global land and global ocean rainstorm and their contribution rates showed an increasing trend from 1979 to 2016. The global, global land and global ocean total rainfall showed an decreasing trend. The global land total rainfall showed a distinct sectional change pattern, which first increased from 1979 to 2006 and then decreased from 2007 to 2016. The comparison between the rainstorm and the total rainfall in global land and ocean showed that the rainstorm tended to increase in both ocean and land regions from 1979 to 2016, while the weak intensity rainfall tends to decrease in the globe. (2) The results of MK mutation test showed that the global, global land and global ocean rainstorm changed abruptly in the year of 2006, 1999 and 2008, respectively, without passing the 0.05 significance level test. The global, global land and global ocean total rainfall changed abruptly in the year of 1998, 2014 and 1994, respectively, and passed the test of 0.05 significance level. The rainstorm contribution rates of global, global land and global ocean changed abruptly in the year of 2006, 2003 and 2007, respectively. Only global land rainstorm and global ocean rainstorm passed the 0.05 significance level test. The year of abruptly change of global rainstorm and total rainfall were consistent with the year of ENSO warm event or the year of transition from cold event to warm event. (3) The global land and ocean rainstorm and total rainfall did not change consistently on multiple time scales from 1979 to 2016, but showed inverse phase or forward and lag phase correlation. Fourthly, compared with ENSO, global land (ocean) rainstorm changed earlier (lag) in high energy spectral region. Compared with ENSO changes in low energy spectral region, global land rainstorm changes were consistent or ahead of time, while global ocean rainstorm changes were mainly ahead of time compared with ENSO changes.