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 summer monsoon transition zone in China is one of the regions with strong land-atmosphere interaction in the world, and it is also an area where extreme weather disasters are frequent and easy to cause serious economic losses. Further understanding of land-atmosphere interaction in the transition area will help to improve the disaster prevention and mitigation ability of this region. Based on the research results of the summer monsoon transition area related projects carried out by the Key Laboratory of Drought Climate Change and Disaster Reduction of China Meteorological Administration in recent years, this paper systematically summarizes the new progresses of land-atmosphere interaction in the summer monsoon transition zone, including the spatio-temporal distribution law of land-atmosphere interaction in the transition region, the new characteristics of the response of land surface water budget to summer monsoon, the spatio-temporal variation characteristics and development mechanism of the boundary layer, the influence of monsoon and land-atmosphere interaction on regional climate in the transition zone, the new progress of land-atmosphere interaction on crop yield in the transition zone and new schemes for parameterization of multi-factor and multi-scale kinetic roughness. According to the development trend of land-atmosphere interaction research in the summer monsoon transition zone, it is proposed that the multi-scale dynamic response of land-atmosphere interaction to summer monsoon should be explored in the future, and the climatic dynamic relationship between surface processes and key physical quantities in the atmospheric boundary layer should be established on the basis of the research on the response rule of land-atmosphere exchange multi-cycle process to the annual cycle of summer monsoon in order to improve and enhance the simulation of regional climate models in the future. This work is of great significance to promote the research of land-atmosphere coupling process in China, which can provide scientific and technological support for disaster prevention and mitigation in the summer monsoon transition zone in China.

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.

Constructing suitable meteorological drought indicators is an important foundation for drought monitoring and drought evaluation services. Based on the daily average temperature and precipitation of 155 national meteorological stations in Sichuan Province from 1997 to 2021, as well as the crop area data of each county (city or district), the modified meteorological drought composite index (MCI_m) is formed by improving the seasonal adjustment coefficient of the meteorological drought composite index (MCI). The regional drought process identification method was revised according to annual drought disaster area and annual effective irrigation area and 51 regional drought processes in Sichuan Province were identified in the past years. The temporal and spatial distribution characteristics of regional drought processes in Sichuan Province were analyzed by using empirical orthogonal function (EOF), rotated empirical orthogonal function (REOF) and Morlet wavelet analysis. The results show that the evolution results of the durative day, average intensity, average impact area and comprehensive intensity index of the regional drought processes in Sichuan Province decrease initially, followed by increase, but then again decrease. The average annual cumulative days of regional drought process in the basin area were more than those in the mountains area around the basin, and those in the mountains area around the basin were more than those in western Sichuan Plateau and Panxi area. The spatial pattern of annual accumulated MCI_m anomaly decomposed by EOF was consistent in Sichuan Province and was also opposite in the northern and southern parts of Sichuan. Sichuan Province can be divided into six drought climatic areas. The annual cumulative MCI_m periodic change from 2009 to 2015 was more obvious than that from 2001 to 2008 in each area. The identified regional drought processes according to improved regional drought process identification method are in good agreement with the drought disaster situation and could better reflect the actual situation of drought in Sichuan Province more accurately.

In order to explore the response mechanism of photosynthetic physiological process of spring maize to soil water and temperature changes in semi-arid region of the Loess Plateau under the background of climate change, taking spring maize as the research object, the pot water control experiment was carried out in the Dingxi Arid Meteorology and Ecological Environment Experimental Base of China Meteorological Administration in 2017. Control treatment (CK treatment, soil moisture at 80% of field water capacity) and water treatment (WS treatment, soil moisture at 45%-50% of field water capacity) were set at spring maize seven-leaf stage. Three leaf temperature gradients were set, which were optimum temperature 25 ℃, high temperature 35 ℃ and extreme high temperature 40 ℃ (CK treatment corresponds to CK-25, CK-35 and CK-40; WS treatment corresponds to WS-25, WS-35 and WS-40). The response characteristics of leaf gas exchange parameters and water use efficiency to soil moisture and temperature changes at seven-leaf stage of spring maize were analyzed. The results show that within a certain range of photosynthetically active radiation (PAR), the net photosynthetic rate (P_n) of leaves gradually increased with the increase of PAR. When water supply was insufficient, with the increasing of PAR, stomatal limiting factors of spring maize leaves under WS treatment transferred to non-stomatal limiting factors, and photosynthesis is inhibited obviously. The P_n of spring maize leaves under WS-35 treatment was the highest, and P_n of maize leaves under WS treatment was significantly lower than that under CK treatment in the PAR high value area. The PAR at light saturation point decreased under different temperature gradients. Compared with CK-40 treatment, the P_n of spring maize leaf under WS-40 treatment decreased significantly with the increase of PAR (P<0.05), and photoinhibition was obvious. When the water supply was sufficient, the transpiration rate (T_r) increased with temperature increasing. When the water supply was insufficient, compared with CK-40 treatment, the T_r and stomatal limitation (L_s) of spring maize leaf decreased significantly (P<0.05), while intercellular CO₂ concentration (C_i) increased significantly (P<0.05) under WS-40 treatment. With the increase of PAR, T_r decreased and water use efficiency (WUE) of spring maize treated by WS-40 was higher than that CK treatment. This study can provide reference for the physiological characteristics of spring maize in semi-arid region of the Loess Plateau under the background of climate change.

Based on the daily meteorological observation data at 441 national meteorological stations in southwestern China in summer from 1961 to 2022, the basic climatic situation, characteristics of high temperature and drought disasters and their main impacts in southwestern China in summer 2022 are analyzed. The results show that the severity of this extreme high temperature and drought event is historically rare. Compared with the historical corresponding period, the average temperature and the extreme maximum temperature were the highest, the precipitation was the least, and the high-temperature days was the most in the summer of 2022 in southwestern China. In addition, the persistent high temperature was accompanied by a severe meteorological drought in eastern part of southwestern China. The 105 meteorological stations of the central Xizang, most areas of Sichuan, most areas of Chongqing, the north of Guizhou and local regions of central Yunnan happened extreme droughts. Under the impacts of the compound high temperature and drought, the output of some crops in the east of southwest China reduced, even extremely, the inflow of rivers appeared a rare phenomenon of ‘returning to dry in flood season’, and the power load hit a new record and the hydropower generation decreased sharply, resulting in a shortage of energy supply. Moreover, several forest fires broke out in eastern Sichuan Basin and western Chongqing. This article aims to understand this extreme high temperature and drought event from a scientific perspective, facilitate the development of meteorological disaster risk assessment, provide scientific and technological support for improving disaster prevention and mitigation and dealing with climate change.

Drought is one of the natural disasters with the widest impact and the most serious economic losses in China, which directly threatens the country’s food security and socio-economic development. The understanding and research on drought will help to improve the national capacity of drought prevention and mitigation. Since 1949, China’s research on drought meteorology has achieved fruitful results. Based on the research results of the scientific research project group related to drought meteorology carried out by the Key Open Laboratory of Arid Climate Change and Disaster Reduction of China Meteorological Administration since the 21st century, through the achievement retrieval, this paper summarizes the new progress in drought monitoring technology, drought temporal and spatial distribution, drought disaster-causing characteristics, drought disaster risk and its response to climate warming, as well as drought disaster risk management and defense technology. At the same time, based on the frontier development trend of drought meteorology research, on the basis of strengthening the comprehensive drought observation test in drought prone areas under the background of climate change, this paper puts forward that China’s drought meteorology research in future should study quantitatively the formation mechanism of drought from different dimensions and scales, build a new comprehensive drought monitoring method of multi-source data fusion and multi-method combination, reveal the mechanism of drought disaster-causing and evaluate scientifically the drought disaster risk, putting forward the executable risk management strategies. This work is of positive significance to promoting drought meteorological research in China.

The drought event in the whole Yangtze River Basin, which started in June this year and lasted till now, not only has a very serious impact on agriculture, energy and other aspects, but also shows many unique characteristics in development process and impact feature of drought that are rarely seen in the past, it is very necessary to conduct scientific analysis on it. On the basis of both science and popular science, from the perspectives of the new normal and the anti-normal, respectively, this paper tries to make some simple scientific interpretation of the current severe drought event in 2022 in the Yangtze River Basin, from the aspects of the performance characteristics, formation mechanism, influence characteristics and the enlightenment and thinking obtained from the drought, so as to promote the public scientific understanding of the drought event.

Based on the SRTM (shuttle radar topography mission)data, the ground clutter and other clutters around Tianshui radar station were filtered, then the Z-I function with localized parameters was established on the basis of six precipitation processes with three types in Southeast Gansu after filtering the ground clutter and other clutters of radar data, and at last the reflectivity factor of Xifeng new generation weather radar in Qingyang was compared with the one in Tianshui within the coincidence range. The results show that SRTM data can well simulate the distribution of ground clutter; radar reflectivity is ahead of precipitation; the Z-I function with localized parameters in Tianshui, which had a smaller A and bigger b, is significantly different to common ones; Tianshui new generation weather radar may have a systematic problem of low echo intensity.

Considering the different disaster-pregnant environment, population density and economic condition, the drought disaster chain models in southwest and south China were constructed respectively by using history data and record of references. Here, the disaster-pregnant environment includes climate background, underlying surface, landforms, soil and river network. And on this basis that the transmission characteristics of disaster on separate disaster chains were analyzed. The results show that the drought disaster chain structure is similar in southwest and south China, but their transfer process of disaster on the two chain is different. There are obvious regional characteristics of disaster transfer on their chain. The incipient drought can cause crop drought in southwest China, while moderate drought can cause crop drought in south China. In southwest China, the moderate drought can lead to some problems such as people and livestock drinking water difficult and livestock forage shortage, but these corresponding problems can be generated by the severe drought in south China. Being the difference in disaster-pregnant environment, the rock desertification phenomenon appears in southwest China under the severe drought condition, but the probability of rock desertification is small in south China except for north Guangxi. In the same region, as far as the various disaster-affected bodies are concerned, the threshold of drought degree transmitting is different. For example, shipping problems usually result from the moderate drought, and forest fire and pest disaster are often led by the severe drought, while soil degradations appear in the extreme drought.