It is of great significance to study the change of vegetation cover and the influence of climate factors in Ganzi Prefecture for ecological protection and development. Based on MODIS (Moderate-resolution Imaging Spectroradiometer) -NDVI (Normalized Difference Vegetation Index) data during 2003-2022, trend analysis, Hurst index were used to analyze the changes in vegetation cover in Ganzi Prefecture over the past twenty years. Temperature and precipitation data which are significantly correlated with vegetation index were used to analyze the relationship between vegetation cover change and climate factors. The results indicated that NDVI in Ganzi Prefecture showed an overall upward trend during the study period, and the distribution of vegetation cover was correlated with altitude and watershed. In the past twenty years, the area of vegetation cover increasing accounted for 67.83% of the total area of Ganzi Prefecture, and 25.37% of the area may maintain the same evolution trend as the present in the future. There are regional differences in the spatial distribution of precipitation and temperature, and the precipitation fluctuates significantly in summer, which is related to the influence of Qinghai-Tibet High Pressure in summer. Compared with precipitation, the correlation between temperature and NDVI is more significant. The influence of precipitation and temperature can explain 70% of the regional vegetation cover change during the study period, and the contribution of temperature to vegetation cover change is higher than that of precipitation.
In order to make an in-depth study of the characteristics of high temperature and drought in Jiangxi Province, the assessment model for regional high temperature and drought processes was constructed based on daily precipitation and temperature data from 81 national meteorological stations in Jiangxi Province from 1959 to 2022, which included indicators such as influence range, process duration and intensity. And regional high temperature and drought processes in Jiangxi Province in the past 64 years, especially the abnormal characteristics of regional high temperature and drought processes in 2022 were comprehensively analyzed and evaluated. According to the coincidence days of hot and drought, the compound year of hot and drought was defined. The results show that 277 (90) regional high temperature (drought) processes occurred in the past 64 years, and in 37 years the hot and drought processes appeared in the same year, and in 22 years high temperature and drought overlapped for more than 10 days. The increase of compound hot and drought years is particularly significant after 2000. The average daily temperature and the average of daily maximum temperature in Jiangxi Province in summer and autumn of 2022 were the highest at the same period since 1959. There were 5 regional high temperature processes in the summer and autumn of 2022，which lasted for 71 days. The comprehensive strength of the high temperature process from July 20 to August 30 of 2022 reached extra heavy grade, which ranked the first in history. The average rainless days in Jiangxi from late June to mid-November in 2022 reached 124.1 days. Persistent high temperature and little rainfall in summer and fall in 2022 led to continuous severe drought in Jiangxi Province, and the intensity of meteorological drought was the second severe drought process since 1959.
Based on the sounding date from captive boatover the hinterland ofTaklimakanDesert inwinterof2008, the atmosphere stability therewas studied elementarily using three differencemethodswhich areTemperature differencemethod,Temperature differenceW ind speedmethod andRichardson numbermethod. Results showed: (1)The diurnal change of the atmosphere stabilitywas obvious in Tazhong, atnight the state of the atmosphere changed from stability to neutral then instabilitywith the height increase, and the surface layerwas instable due to the impactof the solar radiation in daytime; (2)The atmosphere stability has significantly stratificationwith the height increase, the stable and the instable layer appeared alternately; (3)The results calculated by the above threemethodswere different, which reflected that the atmosphere stabilitywas influenced by temperature,wind and turbulence.
Ground - based meteorological observation is essential for understanding the relationship between alp ine glacier and climate change, especially in remote regionswhere in - situmeasurements are extremely limited. Themeteorological factors, including air temperature, wind speed and direction, atmospheric water content, were measured over the accumulation area on the East Rongbuk Glacier, Mt. Qomolangma ( theMt. Everest) at elevation of 6 560 m. Measurements were conducted using an automatic weather station (AWS) fromMay 1 to July 22, 2005 ( sp ring - summer period) and from October 2, 2007 to January 19, 2008 ( autumn - winter period). The variational trend of air temperature and atmospheric water contentwere nearly similar at both the measurement site and Dingri meteorological station by analyzing the observations, and this result testifies the rationality of the observed data on the extremely difficult conditions. Mean monthly air temperature ranged from - 11. 3 ℃ inMay to - 3. 4 ℃ in July, 2005 and from - 11. 3 ℃ in October,2007 to - 19. 0 ℃ in January, 2008 at the AWS site on the East Rongbuk Glacier in theMt. Qomolangma region. Near - surface the mixing ratio of water vapour increased from 1. 4 g/kg inMay to 5. 4 g/kg in July of 2005 after onset of the Indianmonsoon, while it decreased very slowly from 1. 4 g/kg in October of 2007 to 0. 5 g/kg in January of 2008 when the westerlieswas dominated in the region.Surface wind characteristics were strongly controlled by two major synop tic circulation regimes: the Indian monsoon regime in summer and the westerlies in winter. At the AWS site on the East Rongbuk Glacier, north or northwestwinds p revailed and mean monthlywind speed ranged from 7. 1 m / s in October, 2007 to 14. 2 m / s in January, 2008 with the extreme value up to 35 m / s. South or southeast winds p redominated after the onset of the southwesterly Indian monsoon with relatively low wind speed in summer, ranging from 6. 9 ms- 1 inMay to 2. 2 m s- 1 in July, 2005.
The method for drought monitoring by remote sensing and monitoring flow were introduced in the paper，which can transfer NOAA／AVHRR data received from DVBS system to Erads software where geographical correction and image mosaic can be done，and drought monitoring model can be made and Inn．Drought occul"l~d in four provinces ofNorthwest China in the last ten—day of July， 2006 was monitored by using this method and work flow．an d the results were in agreement with observations of soil moisture in this area．It shows if proper drought monitor model is chosen，the drought magnitude can be monitored by this method and work flow．
This article summarized domestic scholars’research results on sand - dust storm in recent years from its origin, characteristics, transportation, influence and p revention countermeasures. Some p roposal is put forward for sand storm research in the future.
The method for drought monitoring by remote sensing and monitoring flow were introduced in the paper，which can transfer NOAA／AVHRR data received from DVBS system to Erads software where geographical correction and image mosaic can be done，and drought monitoring model can be made and Inn．Drought occul"l~d in four provinces ofNorthwest China in the last ten—day of July，2006 was monitored by using this method and work flow．an d the results were in agreement with observations of soil moisture in this area．It shows if proper drought monitor model is chosen，the drought magnitude can be monitored by this method and work flow．
Based on meteorological data and social - economy data，the paper analyzed the characteristic of meteorological disasters occurred in Gansu province，the fact of climate change during recent 50 years was also observed. The results show that the ecological environment has been significantly affected by global warming and unreasonable human activities in Gansu province. The adaptive policies of climate change and sustainable development were also discussed in the paper.
Dronght is the most serious meteorological disaster in GanSll 1neSS pltateall. It considering meteorological factors comprehensivly because of the complexity Model of America and the modified Pahner Drought Severity Model for of drought .On is difficult to develop a drought index the base of the Palmer Drought Severity China, we fLn-ther modified the model in stations CalClllatlOn Of pOtentlal eVapOtTanSplTatlOn and TLInOff, etC. AS a TPSlllt ,a TPV1Sed m0(lel Of dTOllght SPVPTlty haS been eStahhShed In paper which is expected to he applicable for drought research on this region.
Based on the mean monthly, maximum and minimum temperature series, the temperature changing characteristics in Urumqi airport in recent 50 years were analyzed in this paper. The results show that the mean annual temperature trends was 0.033 ℃/a, and there were obvious warming trends in spring, autumn and winter, the temperature tendency rate was 0.0949℃/a in winter, which was the largest. But the temperature in summer was dropping by the rate of 0.028℃/a. In recent 50 years, there were cold- warm- cold- warm evolution processes in Urumqi airport. A long cold period was in 1950s which was obvious in four seasons, a warm period was from 1961 to 1975, the second cold period was from 1976 to 1988, another warm period was from 1989 to 2000. 70% of anomalous cold years (seasons) were in 1950s and 41% anomalous warm years (seasons) were in 1990s. The mean annual maximum and minimum temperatures presented obviously increasing trend, and the latter was much steadier. From the results it is known that the minimum temperature would be more sensitive to monitor the intensity of greenhouse.From 1989 to 2000,abrupt warming occurred mainly in nighttime.These facts would contribute to study the temperature change in Urumqi airport.
Based on the measured data of the Bowen ratio-energy balance method（BREB）and radiation in Dingxi Arid Meteorology and Ecological Environment Experimental Station，Institute of Arid Meteorology，CMA，this paper analyses the characteristics of surface energy budget and radiation under different types of synoptic condition sand averaged climatic conditions in spring wheat farmland.The results show that：（1）The characteristics of daily variations of the surface energy budget，the global radiation，the net radiation，the direct radiation and the atmosphere diapha neity coefficient（P2）are quite similar in the different growth stages of spring wheat under a clear day condition，but se values are distinct，these values increased gradually with growth stages of spring wheat；（2）The daily variation of the Bowen ratio is quite similar in different growth stages of spring wheat under a clear day condition.The Bowen ratio of night is bigger than that of daytime，and also the Bowen ratio of antemeridiemis bigger than that of afternoon. The Bown ratio is less than 1.0 in daytime.The biggest Bowen ratio occurs at 3~4P.M.in a day.In the whole growth stages，the Bowen ratio is gradually increscent，the latent heat plays a leading role，and the sensible heat depends on the latent heat；（3）Under different types of synoptic conditions including a clear day and a cloud day，not only the farmland surface energy obtained is variable in magnitude，but the available energy admeasure disdifferent.The daily-integral values of global radiation，net radation under a cloud day is about 30%~40%less than those under a clear day.The range of variation in sensible heat flux and latent heat flux is about 15%between a cloud day and a clear day
By using meteorological data of Dingxi region and EOS／MODIS data，some basic surface parameters and the net radiation of earth’ssurface in the dry-farming region in Northwest China are derived，moreover，the seasonal variety of the net radiation ofearth’s surface is analyzed.The results show that the derived value is close to the observed value，the relative error is less than 16%，which means the derived value may reflect the factin stance；the seasonal variety of the net radiation is least in winter and most in summer and spring，and there is a symmetrical feature of its distribution in different seasons，its frequency distribution range is also wide in this dry-farming region
In this paper，some facts of creeping environment problems in Hexi region of Gansu province were given，it was pointed out that environment deterioration and climate abnormity aroused by humanactivities could impact on the persistent development of society and economy，people should think much of this problem.
The orientation ,current situation ,chance and challenge of special meteorological institutes(SMI) of China Meteorology Agency(CMA) were analyzed Meanwhile ,some important problems on how to establish perfect state special meteorological science and technology innovation system were put forward experimentally according to the view of science acteristics of SMI. Moreover .the practical experience of establishing arid一meteorology science worker as well as the }ecific char and technology innovation system.which was based on the reality of Institute of Arid Meteorology ,CMA .was elaborated
Atmospheric chemistry is an booming discipline in atmospheric sciences. Its researches started one hundred years ago.but the observation of atmospheric owne and theoretical researches in owne actinic chemistry are milestone. Many facts and phenomena in atmospheric chemistry field are not understood at present .especially some problems on sinks.sources and spatial and temporal distribution of some atmospheric trace elements and their migration .transfer and global cycle is necessary to more deeply and widely observe and research.
The science objectives and principal results of the representative land surface process experiments(LSPE) such as FIFE, LBA,HEIFE,IMGRASS,TIPEX and GAME一Tibet and so on ,which have been carried out since 1980's, are introduced.while .the weaknesses of LSPE are pointed out as well as what will be emphasized in the future.
