A review on relationship between subtropical high anomaly over West Pacific and summer precipitation in the middle-lower reaches of the Yangtze River

The effect of subtropical high anomaly over West Pacific on summer precipitation in the middle-lower reaches of the Yangtze River was reviewed. On the basis of intensity and location of subtropical high over West Pacific and its formation reasons, the effect and mechanism of subtropical high anomaly over West Pacific on summer precipitation in the middle-lower reaches of the Yangtze River were summarized. The results indicate that dynamic factors and thermodynamic factors both affect subtropical high. There are 3-4 years and 10-13 years oscillation periods for subtropical high intensity over West Pacific. There is an abrupt change about 1978. The ridge position index starts to move from positive to negative, while the strength index is contrary. These changes influence significantly precipitation in the middle-lower reaches of the Yangtze River. The location, shape and intensity of subtropical high over West Pacific are one of decisive factors for drought and flood in the middle-lower reaches of the Yangtze River. There are generally four methods to be used to predict precipitation in the middle-lower reaches of the Yangtze River based on subtropical high over West Pacific. Finally, some existed problems and further directions are briefly discussed.