Based on the ozone mass concentration monitoring data near surface of Yinchuan and ground and upper meteorological observation data over Eurasian area from 2014 to 2016, the influence of meteorological conditions on ozone mass concentration was probed systematically from two aspects of meteorological factors and atmospheric circulation pattern. The results show that the ozone mass concentration near surface of Yinchuan was positively correlated with air temperature and negatively correlated with relative humidity, respectively. The vertical mixing played a dominant role when the wind speed was low, the ozone mass concentration was positively related with wind speed, while the horizontal diffusion played an important role when the wind speed was high, the ozone mass concentration was negatively related with wind speed. The southerly wind and wind direction towards Helan Mountain were conducive to the increase of ozone mass concentration. There were five circulation patterns on ozone polluting days in Yinchuan: trough and ridge pattern (44%), wide trough pattern (21%), subtropical high pattern (16%), northeast ridge pattern (8%) and others pattern (11%). The inversion layer near surface and sea-level low pressure system (or inverted trough) were important synoptic systems which caused ozone pollution in Yinchuan.

Based on the ozone mass concentration data in Ningxia from 2015 to 2018, the variations of O3 mass concentration in five cities of Ningxia were analyzed and compared, and the influences of airflow on O3 mass concentration in five cities of Ningxia were discussed by using back trajectory cluster analysis method and the global data assimilation system. The results show that the 90% quantile of O3 mass concentration in Shizuishan was the highest (159 μg·m-3), followed by Yinchuan (154 μg·m-3), Zhongwei (149 μg·m-3), Wuzhong (137 μg·m-3), and Guyuan (132 μg·m-3) during 2015-2018. In the past four years, the O3 mass concentration in Shizuishan decreased slightly, while that in other four cities increased. The days on which  primary pollutants was O3 was 124 days in Shizuishan, 119 days in Zhongwei and 103 days in Yinchuan. The days on which primary pollutants was O3 and air quality was good and  light pollution increased in all 5 cities. Except for Guyuan, the frequency of O3 pullution processes with 6 d and 7 d  duration increased in other cities, especially in Yinchuan and Zhongwei. For Shizuishan, Yinchuan and Wuzhong, the middle-distance and short-distance northwest airflow accounted for the highest percentage of the total airflow trajectory, followed by the southeast airflow and the north airflow. For Zhongwei and Guyuan,the percentage of the southeast airflow  was the highest, followed by the short-distance northwest airflow, and then the middle-distance and long-distance northwest airflow. The northern airflow from central Mongolia, central and western Inner Mongolia, across the northern and central Ningxia was the most important transport path affecting the O3 mass concentration, while the southeastern airflow from south central Shaanxi, northeastern Gansu and middle east Ningxia was the most important transport path affecting the ozone mass concentration in Shizuishan, Yinchuan, Wuzhong and Zhongwei.

Based on precipitation and temperature data of 21 stations in January in Ningxia region,  NCEP / NCAR monthly height and wind grid data of 2.5 × 2.5 °over Northern Hemisphere from 1961 to 2008, and NCEP Eurasian snow cover data from 1973 to 2007, the formation mechanism of the extremely cold and snowy weather event accurred in January 2008 in Ningxia region was analyzed. Results show that the anomalous atmospheric circulation was one of the most important causes. La Nina event and Eurasian snow cover anomalies resulted in atmospheric circulation anomaly, then anomalous precipitation occurred in January in Ningxia.

The dates of the first soaking rainfalls in the south and middle parts of Ningxia were forecasted statistically by using the optimal subset regression method, the forecast equation was set up and it king rainfall in the regions in recent 30 years was discussed in detail effect was analyzed, and the(hange of the dates of the first soarainfall is 23.3% in April, 23.3% in May, and 33 Results show 3 %  in .Tune that the occurrence in Yinc;huan region
probability of the first soaking ，during the last 30 years the dates of the first dates of the first Apri1,20% and tinn fnr the dates   in March, 20% soaking rainfalls were later in 1970x, earlier in 1980x, and medium in 1990s between that in 1970s and 1980x.  The soaking rainfall(onc;entrated relatively in southern mountain areas of Ningxia, the probability of o<(urrenc;e is 53% in 17% in May and Marc;h,and only 10% in June, and it is found that there is a slight trend of postponing with fluc;tuaof the first soaking rainfalls in this region in recent 30 years. The effect of forecast using the optimal subset regression method for the date of the first soaking rainfall is good in  Ningxia