Spatiotemporal variations of tropical and non-tropical cyclone-induced rainfall over southeast China and the teleconnections to climatic indices

The spatiotemporal variations of annual tropical cyclone- and non-tropical cyclone-induced rainfall (TCR and NTCR) during 1960 – 2017 in Southeast China are investigated in this study. The teleconnections to sea surface temperature, Arctic Oscillation, Southern Oscillation, and Indian Ocean Dipole are examined. A significant decrease in annual TCR in the Pearl River Basin was detected, while an increase in annual TCR in rainstorms was observed in the northeast of the Pearl River Basin and south of the Yangtze River Basin. Northward migration of a TCR belt was identified, which was also indicated by the pronounced anomalies of annual TCR. There was in general an increasing trend of non-tropical cyclone-induced moderate rain, heavy rain, and rainstorms in Southeast China. Compared with the non-tropical cyclone-induced heavy rain, the abnormal non-tropical cyclone-induced rainstorms are more northerly. Both monthly TCR and NTCR were remarkably affected by the Arctic Oscillation, Southern Oscillation, and Indian Ocean Dipole. TCR was more easily affected by Arctic Oscillation compared to NTCR.