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.

To improve the forecast and early warning ability for the low visibility along the expressway, the hourly observation data of 10 traffic meteorological stations along Shaanxi section of the Lian-Huo expressway and the hourly reanalysis data of the European Center for Medium-Range Weather Forecasts are employed to analyze the distribution characteristics of low visibility and to explore the relationship of low visibility with other meteorological factors. The results show that along Shaanxi section of the Lian-Huo expressway, January has the most low visibility, while February has the least. During a day, the low visibility mostly happens from 00:00 to 10:00, and the low visibility of 0-50 m mainly occurs from 05:00 to 06:00. The low visibility duration is short with the majority of within 2 hours and the longest of 17 hours. The low visibility weathers occur frequently from Xingping to Changxing and Chencang section, where attention should be paid in daily traffic meteorological service. Accordingly to the analysis of the relationship between low visibility and other meteorological factors, the low visibility generally occurs under the conditions of air temperature from 0 to 5 ℃, relative humidity above 90%, wind speed less than 1.0 m·s^-1 and northeast to east winds. The low visibility weather in summer and winter is mostly associated with precipitation, which usually occurs during or after the precipitation and is accompanied by weather systems always. Compared with the low visibility caused by radiation cooling, the low visibility associated with precipitation exhibits longer duration and the wider range. The low visibility weathers occur at different relative humilities in different seasons, which in winter, summer and autumn are high, while in spring are relatively low.

Based on the hourly precipitation data from 302 regional automatic weather stations in the Loess Plateau arid region of eastern Gansu from 2013 to 2020, digital elevation model data from shuttle radar topography mission and ERA5 reanalysis data of European Centre for Medium-Range Weather Forecasts, etc., the spatio-temporal distribution characteristics of short-term heavy rainfall are analyzed, and on this basis that the relationship between it and topography, geography factors is discussed. Then combined with an extremely short-term heavy rainfall event in 2021, the influence mechanism of terrain is summarized. The results are as follows: (1) The short-term heavy rainfall mainly occurs in summer in the Loess Plateau arid region of eastern Gansu, and in July the proportion of short-term heavy rainfall days （35.9%） is the most and the extremity is the strongest, while in August the proportion of short-term heavy rainfall times (46.9%) is the most and the rainfall intensity is the strongest. The rainfall intensity mainly ranges from 22.0 to 31.0 mm·h^-1, and it shows a multi-modal diurnal distribution with the most active, strongest and most extreme from 17:00 BST to next 00:00 BST, whose proportion of times is 56.8%. (2) The spatial distribution of the occurring times and hourly precipitation extremum of short-term heavy rainfall events is extremely uneven. The occurring times is less in the northwest and more in the southeast, it decreases sharply with the increase of rainfall intensity, and the short-term heavy rainfall occurs frequently in the area with valley bell-mouth topography, moreover, the palm landform is also the high incidence area of heavy precipitation above 30.0 mm·h^-1. The extremum is small in the middle and large in the northeast and southwest, the large value mostly distributes in eastern Qingcheng and western Heshui. (3) The influence of geographical and topographic factors on occurring times of short-term heavy rainfall is significant, and its contribution comes from geographical location, while their influence on precipitation extremum isn’t obvious. In general, the topographic forced uplift isn’t main influence mechanism on short-term heavy rainfall in the Loess Plateau arid region of eastern Gansu. (4) The mountain-valley wind circulation and surface mesoscale convergence line induced by it are important inducement for the formation of short-term heavy rainfall in valley bell-mouth topography area in the Loess Plateau arid region of eastern Gansu.

Research on highway traffic disaster risk is a new direction for the development of professional meteorological services, and it is an important content of traffic weather forecasting services in future. Based on the ground observation data at 94 weather stations in Shaanxi from 1980 to 2017, the temporal-spatial change characteristics of road icing under different weather conditions were analyzed by using EOF method, etc., firstly. And the risk warning model of road icing in Shaanxi was discussed and established. The results show that there were two centers of road icing in the northwest of Guanzhong to the west of northern Shaanxi and Shenmu of northern Shaanxi, and the ratio of sleet or snowfall road icing was the maximum. The road icing mainly occurred from November to next March in Shaanxi, and the beginning date of road icing generally occurred in mid-to-late October in northern Shaanxi and Guanzhong, while that occurred later in November in southern Shaanxi, but the ending date of road icing mainly occurred in March and April in three regions, and the road icing days in January was the most. After the 1990s, the days of road icing decreased. The risk warning model of road icing was established and applied to business system in Shaanxi, and it could complete automatic production, the prediction effect was better.

Based on the observation data of hourly temperature，daily maximum and minimum temperature，daily mean total cloud cover and rainfall from ten stations in Shaanxi Province from 2006 to 2010，a forecast method of hourly temperature was established by using linear regression method on the basis of forecast values of daily maximum and minimum temperature and observed values of hourly temperature，which was tested by comparing forecast values with observed values of hourly temperature at ten stations in Shaanxi Province in 2011． The results show that the forecasting ability of the forecast method of hourly temperature under sunny or lightly cloudy conditions was better than that under heavily cloudy or rainy conditions． The forecasting effect of the method was better between 2 o clock
and 18 o clock than that between 19 o clock and 1 o clock of the next day on sunny or lightly cloudy days，and was better between 1 o clock and 10 o clock than that at other time on heavily cloudy or rainy days． When the forecasted daily maximum and minimum temperature were comparatively accurate，the forecast accuracy of hourly temperature was more than 60% at Xi an station． The accuracy was 100% on sunny days and from 96% to 99% on lightly cloudy days between 14 o clock and 17 o clock． But the accuracy on heavily cloudy or rainy days was about 12% ～ 27% lower than that on sunny or lightly cloudy days between 11 o clock and 17 o clock． With the characteristic of diurnal variations of temperature change in different areas，seasons and sky conditions，the method can turn
the forecasted daily maximum and minimum temperature into forecast of hourly temperature well． To some extent the forecast method of hourly temperature has application and extension values．

In order to master the occurrence regularity of winter wheat late frost injury in He nan Province，and take timely measures for disaster prevention and reduction，this paper firstly selects these risk evaluation indexes including the winter wheat late frost harmful chilling accumulation and frequency (risk) ，the planting area of winter wheat (exposure) ， and the ratio of irrigated and tillable field area，well number per unit area (vulnerability)to establish risk evaluation system，and then determines the weight of winter wheat late frost risk evaluation index by using analytic hierarchy process，finally the winter wheat late frost freeze risk evaluation model was built． Based on 1984 － 2013 climate data， the late frost of winter wheat in He nan Province was evaluated by using the risk assessment model，and according to the winter wheat late frost risk evaluation model for grid computing in ArcGIS，the winter wheat late frost risk zoning map in He nan Province was obtained． The results show that the late frost risk index was high which ranged from 0． 289 to 0． 483 in the eastern Shangqiu，Zhoukou，Luohe，most part of Zhumadian，some part of Xinyang and Nanyang，while in most of Sanmenxia， Luoyang，Jiyuan，Jiaozuo，Zhengzhou，Anyang，Hebi，Xinxiang and other areas the late frost risk index was less than 0．123． Finally， the correlation analysis was carried out between the late frost index caculated by using historical statistical data and the results of this study，and the correlation coefficient was 0．78，which showed that the winter wheat late frost risk zoning results in He nan Province were consistent with the historical statistics．

|on the physical mechanism of wind erosion and dust emission，the advances on dust storms in China were reviewed
from the micrometeorological perspective，the characteristics of micrometeorological variables and the evolutional discipline of turbulent
fluxes during dust events as well as atmospheric turbulence effect on parameterization of dust storms were introduced． Meanwhile，combining
with relevant research abroad，shortness at present and research direction in the future about dust events research were discussed，
including taking different turbulence parameterization schemes in dust storms modeling and comparing the results with the field
and satellite observations; obtaining the high quality profiles of meteorological variables in the surface layer during dust events; studying
the influences of soil moisture on dust emission thresholds over various dust sources; measuring and modeling dust emission rates
of different soil particle size bins and dust flux profiles．

The predictionmodel for the highestand lowest temperature is established by the CMSVM regressionmethod based on ECMWF data and the extreme temperature observations from 8 automaticweather stations inQingyang ofGansu Province from 2003 to2007.The effect test in 2008 operation forecast indicated that the rate ofaverage forecastaccuracy is64% and 71% for the highestand lowest temperature in 5 days, which has the good instruction for the real-timeweather service. The forecast accuracy rate of the highest and lowest temperature decreased with the forecast time increase, and the accuracy rate for the lowest temperature is higher than thatof the highest temperature. The forecast effect for the lowest temperature is better in spring and summer than that in autume and winter, but it is opposite for the highest temperature. The absolute and the average forecasterrors for the highestand lowest temperature are added with the forecast time increase, and the absolute forecasterror for the highest temperature is bigger than thatof the lowestbut the average error is close and positive. The forecast effect test in Septemper of 2008 indicated that the forecast values presented the similar trend to real time observations for the highest and lowest temperature.

According to the climate data (1953 - 2006) in the farming - pasturing interlocked area of InnerMongolia (Duolun) , the response of local grassland p roductivity to the climate change is analyzed. Climate models (Miami and ThornthwaiteMemorial) are introduced to evaluate the grassland potential p roductivity. It is showed that ThornthwaiteMemorialmodel could better describe the main features of the grassland potential p roductivity change with climate factors in Duolun County, and both temperature and p recip itation increase could enhance the potential p roductivity, but p recip itation is the key climatic factor limiting the potential p roductivity. The grassland actual p roductivity observed in Duolun County is then compared with the effective potential p roductivity. The results show that the p roductivity level of natural grassland is very low (412 kg/hm² ·a) , which is only 26% of its effective potential p roductivity, and there is a large room for imp roving. Both of the potential and actual p roductivities of the artificial grassland are much higher than those of the natural grassland, which indicates that the development of artificial grassland could be highly efficient for imp roving the local
grassland p roductivity. The actual stocking rate in 2000 - 2002 is also compared with the estimated theoretical one, and an average overloading rate up to 79. 3% exists in this period.

The main functions of Surfer software，ActiveX automation technique and the interface of VB application and Surfer are introduced in this paper．It is also introduced how to combine the strong ability of development using VB software and the strong mapping in  Surfer based on the interface．and the key program to Ca／Ty out the interface technique and a case of application automatic mapping are presented．

Based on the Doppler radar data，the characteristics of the echo intensity，velocity，top height and vertically integrated liq-uid water(VIL)of the strong hail on May 30 and the rainstorm on July 1．’2 in 2005 in Qingyang region were analyzed，and compari-sOn between these two weather events Was carried out．Results show that difierence of the reflectivity between the hail and rainstorm Was great；the hail echo developed and moved quickly at the rate of 50 km／h，and the central intensity of hail echo exceeded 50 dBZ；there Was some speed fuzzy area on velocity map，and middle cyclone Was detected by the radar ；山e t0p of cloud Was more than 12 km；VIL increased suddenly before haifal1．and hail occurred when VIL in central was over 20 ks／m ．While the echo intensity of the rainstorm Was only 25—35 dBZ，and rainstorm echo moved slowly；the 0 speed line was regular and it can reflect the low level jet and develop—ment of air mass，and the top height of cloud Was only 5—8 km and VIL changed little during rainfall process．

The support vector machine(SVM) is a new statistical study theory method which developed in recent years,  by using this method in
hail in the method is this paper',  We analyzed  the classific;ation prediction of hail weather based on summarizing the circulation(harac;teristic;s of hail in east region of Cansu provinc;e} and(ompared with traditional forecast under different weather types.It is confirmed that SVM method is not need to classify weather types and the effect of forecast model being established is better on many samples. This has provided new method and idea for hasin stations nn weather forecast.

Using lightning data detected by the TRMM satellite between 25-38 0N and 74-100 0E from 1998 Jan. 1 to 2003 Dec.31,the yearly, seasonal and diurnal lightning number and their change with the longitude and latitude, the lightning density distribution and lightning climatic feature were calculated and analyzed in this paper. Results show that the total mean diurnal lightning number is about 7 600 in Tibetan Plateau Region of China, and it is 66.470l0 of the total number during day and 33.530lo during night，and their ratio is 2.0. The yearly variety of the diurnal flash number is the many peak value, the flash occurs primarily in April to September per year, and the number is 940l0 of total yearly lightning number .First peak occurs in Jun to Auguest, and the second peak in May and September, the flash number in summer season  (Jun to Aug) is 70.230l0, and it is only about 0.830l0 of total yearly lightning number in November to March of the next year. Diurnal variation presents the single peak value, and mean hourly flash  number is about 347 in a year, it reaches a maximum  at 18 PM and it'、about 12.10l0 of diurnal lightning number, it comes to mininn lm during 8一11 AM and it'、only 1.30l0 of the diurnal number, and the maximum is 100 times of the minimum，these show that lightning occurring frequently in Tibetan region is primarily in dusk. In Tibetan region, yearly mean flash number change with latitudd is bigger than that with longitude. Diurnal variation time of peak value occurring lightning in 4 seasons show that the time
with peak value of flash number during a day is different, in winter it is primarily in the evening，in autumn it is in the afternoon, while in spring it is at night and in summer it is at dusk. In Tibetan Plateau region the different yearly mean flash density distributions in daytime and nighttime and all day show that the density is higher in eastern region than that in western region, the hlgh  denStty  area  are  mOTe  COriCenttated  In  Tlhetan  Center  TeglOn  TelatlVely.  DLITlng  daytlme  In  Tlhetan  Center  TeglOn  1S  f1aSh  hlgh density area, and during nighttime it is flash low area. The flash density for different seasons is different, the flash high density area in
spring it is tend to northern, in autumn it is southward, in summer it is highest flash density area in Tibetan region, in winter it is rarelv flash densitv.

Using lightning data detected by the TRMM satellite between 18~30°N and 74~123°E from 1998 Jan , 1 to 2003 Dec,31, the yearly, seasonal and diurnal lightning number and their change with the longitude and latitude, the lightning density distribution and lightning climatic feature were calculated and analyzed in this paper. Results show that the total mean diurnal lightning number is about 54 600 in Chinese land area, and it is 54.47% of the total number during daytime and 45.53% during night time, and their ratio is 1.2. The yearly variety of the diurnal flash number is a pair of peak value , the flash occurs primarily in April to September, and the number is about 92% of the total lightning number in a year. First peak occurs in mid-April to mid-May and the second in June to August, and the second peak is 43.4% of the total yearly lightning number, the flash number in summer (Jun to Aug) is 60% of the total yearly number , and it is only about 0.4% in November to February of the next year.
Diurnal variation presents the single peak, and its range is large, mean hourly flash number is about 2 275 in a year, it reaches a maximum at 18:00 P.M. and it’s about 9.1% of the diurnal number, it comes to a minimum at 9:00~11:00 A.M. and it’s only 3% of the diurnal number, and the maximum is 12 times of the minimum, these show that lightning occurring frequently in Chinese district is primarily in dusk. Diurnal variation presents the single peak, the range of the peak is broad, mean hourly flash number is about 2 275 in a year, it reaches a maximum at 18:00 P.M. and it’s about 9.1% of the diurnal flash number, it comes to a minimum at 9:00~11:00 A.M. and it’s only 3% of the number, and the maximum is 12 times of the minimum. The yearly mean
flash number change with latitude is bigger than that with longitude in Chinese district, the flash number is more in coastal land area than that in inland area, and it is more in inland area than that in sea area, it is more in eastern region than that in western region. The diurnal changing time of peak value occurring lightning in 4 seasons shows that the time with peak value of flash number during a day is different, in winter it is primarily at noon, in autumn it is in the afternoon, while in spring it is at night and in summer it is at dusk. The different yearly mean flash density distribution in daytime, nighttime and all day in Chinese district show that the density is higher in eastern region than that in western region, the high flash density areas are more concentrated relatively. The high flash density areas in daytime are nearby sea, while they are in inland area during nighttime, and the high density areas in daytime are the low flash density areas during nighttime, and vice versa, but there is no such change in Tibet Plateau. The flash density value and its distribution feature are different in different seasons,in spring the high flash density areas are in south part of China, and the large part of inland are the sub-high flash density area, and the density is relatively low in coastal area . In summer the flash density is
higher and the area is larger, the higher density areas are consist with the areas with high yearly mean flash density and they are near sea, while the density in inland area is relatively low. In autumn, the relatively high flash density areas are more scattered, the areas are smaller too, mainly in south littoral. In winter, the density is low and the areas occurring flash are small,mainly in south part of 30°N and Sichuan basin.