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.

Based on the data of daily precipitation and mean temperature from 80 national meteorological stations in Anhui Province from 1961 to 2022, the processes of regional extreme climate events are identified according to the objective identification technique for regional extreme events. Average intensity, duration and average influence range are further extracted, which are applied to establish comprehensive intensity assessment model, and then regional high temperature and drought processes in 2022 are comprehensively evaluated. The results show that the average temperature in Anhui Province in the summer of 2022 is 2.2 ℃ higher than normal, which is the highest in the same period since 1961.The precipitation in 2022 is 40% less than normal, which is the fourth lowest since 1961. Persistent high temperature and little rainfall led to continuous severe drought in summer and fall in the south of the Huaihe River in Anhui Province. There are six regional high temperature processes in the summer of 2022, and the high temperature process from August 1 to 23, 2022 has reached the "super strong" level, which rank the fourth in history and is inferior to the high temperature processes in 1966, 1967 and 2013. However, the annual cumulative comprehensive intensity of high temperature in 2022 reached 4496, which is the highest since 1961.Two regional drought processes occurred in the summer and autumn of 2022. Compared with the nine strongest regional drought processes in summer and autumn since 1961, by the end of September 30, 2022 the regional drought process since July 28 has lasted 65 days, and the intensity level is "super strong", which is inferior to the processes in 1966, 1967, 1978 and 2019.

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.

Based on comparative observation data of Dingxi experiment base in May 2017, the instrument accuracy and observation error of the land surface process observation experiment were analyzed. The results show that the error in observation data of HMP45D air temperature and humidity sensor, 107-L soil temperature sensor, WAA151 wind speed instrument, HFP01 soil heat flux plate and eddy system (CSAT3+Li-7500) was small and within the allowable range, which indicated that the data observed by the same instrument were basically consistent. However, CS616 soil moisture observation instrument needs to be corrected. The consistency of long and short wave radiation observed by different types of instruments was very high, and its correlation coefficients were almost 1. The deviation of observation data also directly affects energy closure rate. The observation deviation of turbulent flux caused the uncertainty of surface energy closure rate of 0.61%-2.20% and the observation deviation of available energy caused the uncertainty of surface energy closure rate of 0.08%-1.67%.

Based on the conventional meteorological observation data at 119 weather stations of Inner Mongolia from 1961 to 2018 and the observation data during the growth period at 11 agro-meteorological stations from 1981 to 2018, the temporal and spatial variation characteristics of potato climatic production potential were simulated and analyzed by using step-by-step correction method, and the response of potato climatic production potential to radiation, temperature and precipitation changes were discussed. The results are as follows: (1) The average climatic production potential of potato during the growing period was 18 889 kg·hm^-2 in Inner Mongolia, and it was significantly lower than photosynthetic production potential (32 095 kg·hm^-2) and light-temperature production potential (30 829 kg·hm^-2). (2) The production potential of potato with each level during the growing period decreased non-significantly in Inner Mongolia in the past 58 years, and their inter-annual fluctuations were large, while that of climatic production potential was the largest, it was significantly and positively correlated with precipitation change. (3) The photosynthetic production potential of potato decreased from west to east in Inner Mongolia, the light-temperature production potential of potato was low in eastern and western Inner Mongolia and high in the central, while the high value of climatic production potential of potato mainly appeared in the south-central area. (4) The climatic production potential of potato in most areas of Inner Mongolia decreased non-significantly from 1961 to 2018, while that in central and northern Hulunbuir, northwestern Xing’an League, northeastern Xilin Gol League and western Chifeng increased. (5) The effect of radiation change on climatic production potential of potato wasn’t obvious in most areas of Inner Mongolia. The impact of temperature change on climatic production potential of potato was negative in most areas, and the negative effect was the most obvious in most regions of the central and the west and southeastern Inner Mongolia, while the positive effect concentrated in north-central part of Hulunbuir and northwestern part of Xing’an League. The influence of precipitation change on climatic production potential of potato was positive in most areas of western Inner Mongolia, Hohhot, western part of Chifeng and eastern part of Xing’an League, while that in southern Ulanqab, eastern Chifeng and western and eastern Hulunbuir was negative.

Dew occurs at the bottom of the atmospheric boundary layer and is affected by atmosphere, vegetation and soil. It plays an important role in arid and semi-arid terrestrial ecosystem. In view of the complexity of the physical process of land dew condensation, its observation and simulation started late. The development of dew condensation projection model has undergone three stages including statistical regression, latent heat flux relationship and simplified cloud physics/energy balance model in recent decades. The main scientific problems of dew condensation projection models are summarized: the lack of representative models caused by short observation data series, the unclear of the physical mechanism of dew formation on different underlying surfaces, the lack of effective simulation of natural underlying surface dew, the unreasonable of latent heat flux relationship of land surface models in arid and semi-arid regions. It is necessary to deepen the research on the condensation mechanism of natural underlying surface dew, reveal the influence mechanism of underlying surface properties on the condensation rate, and develop the condensation model suitable for different climatic backgrounds in China

Based on daily climatic elements data simulated by five global circulation models (GCMs) in the coupled model intercomparison project phase 5 (CMIP5) under three representative concentration pathways (RCPs), daily mean temperature, precipitation and solar total radiation from 50 weather stations, and growth period and per unit yield of single-season rice in the south of the Huaihe River of Anhui Province, the climate changes during the growth period of single-season rice in the south of the Huaihe River of Anhui Province were estimated in the 21st century. And on this basis, the climatic productivity potential (YCPP) of single-season rice and its response to climate changes during the growth period were estimated in near term (2018-2039), middle term (2040-2069), and long term (2070-2099) by using the productivity decay method. The results are as follows: (1) The simulation ability of five GCMs to temperature and precipitation in the south of the Huaihe River of Anhui Province was well, and the simulation effect of temperature was better than that of precipitation. (2) The different growth stages of single-season rice in the south of the Huaihe River would be ahead under different RCPs scenarios in the 21st century, and the whole growth period would shorten. The temperature during whole growth stage of single-season rice would continue to increase under different climate scenarios in the future, and the warming rate in the north would be higher than that in the south, especially under RCP8.5 scenario. The precipitation would present a fluctuating change as a whole, but it would increase obviously in southern region, while the solar total radiation would decrease significantly in the future. (3) The estimated climatic productivity potential of single-season rice under different RCPs scenarios would decrease significantly in the 21st century compared with the baseline period, especially in long period. (4) The climatic productivity potential of single-season rice would be negative and positive correlated significantly with mean temperature and precipitation during whole growth stage from 2018 to 2099, respectively, and the negative effect of climate warming on climatic productivity potential would be prominent. In conclusion, the climate change in the future would not be conducive to the improvement of climatic potential productivity of single-season rice in the south of the Huaihe River of Anhui Province.

The monthly，seasonal and annual average temperature series，precipitation in Yongchang during 1959－2009 was analyzed using linear and polynomial regression methods．The results show that the average temperature presented increasing trend，the abrupt change occurred in 1996 for temperature．The annual precipitation also showed increase trend since 1983，and during 1992－2009 annual precipitation was 20．6 mm more than climate average value，and abrupt change occurred in 1984 for precipitation．In the 1960s and the early of 1990s，it was relatively dry，the driest year in history occurred in this period，and during 1970－1978，1992－2009 it was relatively humid，the frost－free period prolonged since 1998，and it was gradually moving to the relatively warm and humid period．

On June 27th，2005，the rocket rainfall enhancement operation was undertaken in Yongchang county of Gansu province，and the process was tracked and monitored by XDR digital weather radar. Through the analysis of synoptic background and radar echoes evolution before and after the rainfall enhancement operation，it was proved that under the favorable weather condition，after the rocket rainfall enhancement operation，the intensity of radar echo was increasing，the scope of radar echoes and the frequency of surface precipitation were enlarging，and the distribution of surface precipitation in 24 hours after the operation also confirmed the effect of this rocket artificial influence on rainfall.