Sandstorm is a serious natural disaster in north China. It is of great significance to carry out relevant research to improve the forecast level of this kind of catastrophic weather. Based on the RegCM-dust model, an extended period numerical prediction analysis of a typical severe sandstorm process in north China is conducted, and the results are compared with NCEP reanalysis data and other analysis results. The results show that the regions with high sediment discharge simulated by the model are mainly located in southern Xinjiang, Mongolia and western Inner Mongolia. The model has a certain forecasting ability for 10 m wind speed, but the simulated wind speed is smaller than the reanalysis data. The changes of dust column content and total sedimentation simulated by the model can reflect the characteristics of the dust storm weather process. The simulated sand-dust mixing ratio has a certain correspondence with the urban pollution index, which indicates that the model has certain forecasting ability for the pollution weather caused by sand-dust.

The northwest region of China is located in the hinterland of Eurasia, in which the source of water vapor is scarce, and drought is its main climatic feature. In recent years, with the continuous increase of regional precipitation, the warming and wetting in Northwest China has attracted great attention from all walks of life. In order to scientifically respond to social concerns, the team used multi-source data to conduct in-depth research on the phenomenon of warming and wetting in Northwest China from multi-scale and multi-dimensional perspectives, and found that the trend of wetting in Northwest China had significant and nonlinear enhancement characteristics. It is recognized that the wetting in Northwest China is expanding eastward, and the land surface evapotranspiration there has a special negative feedback mechanism on climate warming. It is estimated that the warming and wetting trend will still maintain in Northwest China in this century, and the wetting trend is driven by multi-factor comprehensive driving mechanism. The multi-aspect impacts of the warming and wetting in Northwest China are evaluated, and the technical countermeasures to deal with the warming and wetting there are put forward, and the research results of “the enhancement and eastward expansion of climate warming and humidification, formation mechanism and important environmental impacts in Northwest China” are formed. The major consultation report based on the research results has played an important decision-making support for the national strategies such as the development of the western region in the new era and the ecological protection and high-quality development of the Yellow River Basin. The research results were selected as “China's Top Ten Scientific and Technological Progress in Ecological Environment” in 2022, and have also received extensive attention from the international academic communities.

Based on 2-meter temperature data from the second generation monthly dynamic extended range forecast (DERF2.0) model, observational temperature data at 69 weather stations in Gansu Province, reanalysis data of NCEP/DOE and sea surface temperature data of NOAA，the forecast errors of January temperature in Gansu Province by DERF2.0 model from 1992 to 2013 and their relationship with external forcing were analyzed. The results are as follows: (1) The simulated effects of January temperature by DERF2.0 model in eastern Yellow River of Gansu (known as Hedong for short) were better than that in most regions of western Yellow River of Gansu (known as Hexi for short), especially  in Gannan, Linxia, Lanzhou, Dingxi, Pingliang and Qingyang, the average errors between forecast and observation were small and stable, and the linear tendency rates of forecasted temperature in January were consistent with observation from 1992 to 2013, while the average errors were bigger and unstable in most regions of Hexi, and the change trends of forecasted temperature were contrary to actual observation. (2) Although the model could well reflect the inter-annual variation and spatial distribution pattern of January temperature in Gansu, the abnormal centers and values of temperature change were significantly different from the observation. (3) The EOF1 of error field reflected consistent overestimate or underestimate to  January temperature, the EOF2 presented an opposite distribution pattern in Hedong and Hexi, while the EOF3 appeared a reverse phase distribution pattern in Gannan Plateau and other parts of Gansu Province. (4) The main modes of forecast error field were significantly correlated with circulation and sea surface temperature (SST) in key areas, which indicated that the response of model to circulation and SST anomalies was deficient. Therefore, it was partially possible to reduce forecast errors of January temperature in Gansu by adjusting the response ability of DERF2.0 model to circulation and SST in key areas.

The characteristics of precipitation and lightning activity of a strong hailstorm occurring in Gansu Province on 25 August 2012 were studied by using the data from precipitation radar (PR), microwave imager (TMI) and lightning imager sensor (LIS) boarded on the TRMM (tropical rainfall measuring mission) satellite. The results show that there were three dispersed meso-β scale convective systems by analyzing the horizontal structure of the hailstorm. Although the pixel points of convection precipitation were less than that of stratiform precipitation, the averaged rain rate of convective precipitation was 8.2 times larger than that of stratiform precipitation. The top of the hail cloud could reach up to 13 km above ground with strong echoes (>55 dBZ) below about 7.5 km. The cloud thickness with the precipitation rate greater than 45 mm·h-1 was 7 km. The vertical distribution of precipitation profiles under different rain rates showed inhomogeneous characteristic. The precipitation rates of 50 mm·h-1 and 10 mm·h-1  increased first at lower levels and then decreased with the increase of height，their initial reduced height was about 9 km. Analysis of lightning activity of the hail precipitation process showed that most lightning flashes occurred near the strong convective region with radar echoes higher than 40 dBZ and polarization corrected brightness temperature of 85 GHz channel was lower than 210 K.