850hpa Western Pacific Subtropical High's Climatic Feature And Analysis In Early Summer

The results show that the climate mean state flow pattern of 850hPa geopotential height field is similar to the pattern of July, but in 500hPa it is similar to the pattern of January.850hPa WPSH annual variation and seasonal variation of the variance of variance are comparable,500hPa the seasonal variation of variance accounted for a significant advantage, So 850hPa is a more appropriate level than 500hPa to investigate the interannual variability of the summer Western Pacific subtropical high (SWPSH).1520 line is selected as the index line of the interannual variability of the 850hPa SWPSH, defines the western ridge point (IW), area (IA), and the western ridge latitude index (IL). The results show that there some differences between 850hPa and 500hPa in the interannual variability of SWPSH. It is shown that the three indices all have inter-annual variability and the circle is 5a. Further discussion reveals they also have difference:IA has the long circle 10a and the other two indices have 3.3 a circle.SWPSH anomalies have a major impact on the weather and climate anomalies in East Asia. When the location of 850hPa WPSH shifts westward (eastward) and northward (southward) and the area of WPSH is bigger (smaller), A north-south and a east-west+-+anomaly wave train appeared in the 500hPa height field of the Asian region atmospheric circulation, the area of Okhotsk Sea is controlled by blocking high pressure, high latitude cold air path swifts southward, the East Asian mid-latitude cold air is stronger, low pressure disturbance in Meiyu front area strengthens, the East Asian summer monsoon circulation weakens, the cold air in Changjiang and Huaihe River basin is stronger, the precipitation in Changjiang and Huaihe River Basin is above normal; when the area of west Pacific subtropical high is smaller, the ridge shifts eastward and northward, A north-south and a east-west +-+ anomaly wave train appeared in the 500hPa height field of the Asian region atmospheric circulation, the area of Okhotsk Sea is not controlled by blocking high pressure, high latitude cold air path swifts northward, the East Asian mid-latitude cold air is weaker, low pressure disturbance in Meiyu front area weakens, the East Asian summer monsoon circulation strengthens, the cold air in Changjiang and Huaihe River basin is weaker, the precipitation in Changjiang and Huaihe River Basin is lower than normal.For the annual variation, the Western Pacific subtropical high internal vorticity change is them major reason of changing of the location and size of the subtropical high changes. Negative (positive) vorticity transport from boundary to the region can make the potential height of the region higher (lower). If more negative (positive) vorticity is transported from Subtropical high region to the west, the west ridge point moves westward(eastward)side of the output of more conducive to the westward extension of the West ridge points (East back), an area Subtropical high region of increases (decreases); West ridge point latitude index and the southern, boundary vorticity transfer are significantly positive correlated, namely the more region subtropical high output negative (positive) vorticity to the south the more beneficial to the subtropical high shifts southward (northward).The influence of equatorial Pacific SSTa on the 850hPa West Pacific subtropical high ridge point index and area index is significant, and the influence of each sea area on the subtropical high weakens gradually from west to east. When Nino1+2 SSTa is positive (negative) abnormal in the late spring and early summer of the current year, it is beneficial for the West Pacific subtropical high ridge points moves eastward (westward), south (northward), area to decrease (increase). Early summer ridge of 850hPa Western Pacific subtropical high the moves eastward (westward), the ridge moves northward (southward), area is smaller (larger), it is beneficial for SSTa Nino4 area to appear positive (negative) anomaly at the transition of autumn and winter. Relationship between the subtropical high indices and Nino3 area and Nino3.4 areas and show the two features above, but with smaller correlation coefficient. In lead-related analysis, the equatorial Pacific SSTa is higher (lower) in the late spring and early summer of the year ahead, and it is conducive for the area of 850hPa Western Pacific subtropical high in summer to increase (decrease), Ridge point moves southward (northward), westward (eastward). When the SSTa of equatorial eastern Pacific in spring is higher (lower), it is conducive for the ridge point of 850hPa West Pacific subtropical high in summer move northward (southward). In lag correlation analysis,850hPa Western Pacific subtropical high has the greatest impact on the equatorial Pacific sea waters SSTa the in Nino4 area, the smallest area is Nino1+2. In early Summer, when 850hPa Western Pacific subtropical high ridge shifts eastward (westward), the ridge shifts northward (southward), the area is smaller (larger), it is beneficial for equatorial middle and east Pacific area to appear positive (negative) anomaly at the transition of autumn and winter.