In the past half century, the eastern of Northwest China has experienced a warm and dry trend. In this century, this trend is to continue to maintain or change? For this issue, based on the latest observations from the National Meteorological Information Center, the variations of annual precipitation and mean temperature in the eastern of Northwest China were reanalyzed using some statistical methods. From the long-term trend, the winter precipitation in the eastern of Northwestern region is weakly increasing, and there is no obvious trend in summer, but the spring and autumn are decreasing. So it is the decreasing trend of spring and autumn that makes the annual precipitation decrease. Although the changes in precipitation in the year and the four seasons are not completely consistent, they have shown an increasing trend in the past 20 years since the beginning of this century, especially since 2010, the precipitation is more obvious. For the average temperature, the eastern of Northwestern region shows a significant warming trend, and it is more significant in the 1990s. In addition, the characteristics of the south and north regions of 36°N are not completely consistent. Since the beginning of this century, the region north of 36°N has shown a stage of cooling, while the area south of 36°N continues to show warming, but the warming rate is obviously slowed down. In terms of seasons, the average temperature of the four seasons in eastern of Northwestern has increased in the past 58 years. Compared with the south of the region from the mid-1980s to the end of the 1990s, the temperature increase in the north of 36°N is greater than south of 36°N. In the north of 36°N, the warming rate in the spring and summer of the first 10 years of this century has slowed down noticeably. Autumn and winter temperature has shown a stage of cooling, and the same as annual temperature. In the south of 36°N, the spring, summer and autumn have not shown obvious cooling in the past century, but they showed a stage of cooling in the late 1990s. The staged cooling makes the annual average temperature have no obvious change trend in the first 10 years of this century. In addition, whether it is north or south of 36°N, the temperature increase characteristic of the average temperature has changed from the beginning of this century, the temperature increase has slowed down, and even the stage has become cold. Therefore, the annual precipitation and average temperature in the eastern of Northwest China have undergone a turning point since the beginning of this century. Preliminary analysis found that this transitional change with increased precipitation, slower temperature increase and even phased cooling may be related to the conversion of PDO from warm phase to cold phase.
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