Spatio-temporal variation of annual precipitation in China and its response to ENSO

The results showed that the precipitation in the study area was mainly in a downward trend before the mid-1930s, and then turned upward. In the 1950s, the precipitation generally showed a distribution of rising in the west and falling in the east, and this trend continued until the early 21st century. By 2007, except for the central part of the Continental Basin, the overall trend was mainly upward. In this study, 65 El Niño/La Niña Southern Oscillation (ENSO) events were identified, including 24 El Niño events and 41 La Niña events. The precipitation was generally less when ENSO occurred. However, there were differences in the type and intensity of the event. For example, El Niño had a greater impact on precipitation than La Niña did, and extremely strong or strong El Niño/La Niña events had a more significant impact than moderate, weak, or extremely weak ones. The correlation between precipitation and El Niño or La Niña events had some similarities and differences. For example, precipitation was mainly negatively correlated with El Niño and La Niña at the same time, and both correlations were proportional to intensity, but the correlation between precipitation and El Niño was significantly stronger than that of La Niña.