Abstract:The rainfall prediction with AREM (Advanced Regional Eta Model) under the background of T213 analysis and AVN (Aviation) analysis fileds from 1 June to 31 November 2005 is analyzed. The daily average deviation and root meansquare standard deviation of the two analysis fields are computed, and the distribution of the deviation is analyzed. The results show that keeping the other conditions the same, there is obvious difference in the rainfall prediction of AREM between two background fields; as a whole, the prediction is better under the background of AVN analysis field than under T213 analysis field; contrasting the two analysis fields statistically, there were obvious differences in height, temperature and relative humidity, and big deviation over Siberia north of Xinjiang, the northeastern part of Mongolia and the southeast part of Russia, the Bay of Bengal, and the QinghaiXizang Plateau. The weather systems in those areas have important effect on the weather in China.

Abstract:The NRSM (Nested Regional Spectral Model) of the NMC (National Meteorological Center) is used to conduct the shortrange climate prediction for Wenzhou during typhoon seasons (July, August, and September) from 1986 to 1995. The monthly and seasonal precipitation and monthly mean temperature during typhoon seasons in Wenzhou are predicted. Comparison is made between the simulated and the observed results, and it is found that the model performed well in extreme precipitation, July severe flood, and August and September severe drought prediction; the prediction accuracies of the model for drought/flood tendency are 50% to 70% during the typhoon season; and the capability of monthly mean temperature prediction is satisfactory. The model can be put to operational use.

Abstract:The NCEPNCAR data is used to analyze the structures of the Bengal storm landing on 29 April 2006, before and after the landfalling, by means of the WRF (Weather Research and Forecast) mesoscale numerical model. The results show that the structure of the Bengal storm changed remarkably before and after the landfalling, from a symmetric tropical cyclone to a baroclinic asymmetric cyclone, and the structure and moving track of the storm, as well as the rain belt in Yunnan Province, are well reproduced by the WRF model.

Abstract:Droughts and floods from 1961 to 2006 in summer drought seasons in Hunan Province are analyzed by using z index, and the variation characteristics of multiscale drought and flood activities are analyzed by the wavelet analysis method. The results show that there was a significant increasing trend in the flood index in the past 46 years; floods occurred more frequently from the 1990s. It is also found that there were significant periods of 22 years, 12 years, 6 to 7 years, 3 to 4 years in the flood index, and significant periods of 20 years, 10 years in the drought index. Relation analyses between 500 hPa height and z index show that there existed good correlation between z index and 500 hPa height, especially in February. In heavy flood years, 500 hPa anomalies were prominently negative in the eastern Siberian and positive in the subtropical high pressure zone; in contrast in heavy drought years, 500 hPa anomalies were obviously positive in the eastern Siberian and negative in the subtropical high pressure zone.

Abstract:A statistic model for the spatial distribution of precipitation estimation in Urumchi is presented. By using the station information compiled by the National Meteorological Center and the precipitation data of 45 years (1955 to 2000) from three stations in Urumchi，the relations between precipitation and regional geographic and topographic factors such as longitude，latitude, and altitude，is studied with stepwise regression. The results show that the estimated precipitation is highly close to the real distribution of precipitation qualitatively and quantitatively．

Abstract:The current status of the operational agrometeorological service in China, the problems encountered in practice, and the countermeasure are described. According to the needs of modern agricultural development, the developing trends and main tasks of agrometeorological service in China are analyzed. It is pointed out that the agrometeorological service in China has made encouraging progress in the recent 40 years，but there exist some problems such as the backward observation facilities, the limited service scope, and the unsatisfactory technical level of service products. The future efforts should be made on the system construction of modern agrometeorological service with emphasis on the expansion of the service scope, the reinforcement of observation infrastructures, and the integration of agrometeorological service with policymaking and other related sectors. The operation service should be developed towards diversification and refinement so to promote service capability.

Abstract:Using the frost and daily minimum temperature data from 22 ground weather stations in Qinghai Province from 1961 to 2005, the characteristics of frost variation and the main impact on major crops are studied, especially in the Qaidam Basin. The results show that in the past 45 years over the most parts of Qinghai Province, the beginning date of early (autumn) frost postponed, and the ending date of late (spring) frost advanced, most obviously in the eastern agricultural area and then the Qaidam Basin; frostfree periods extended; in the most part of Qinghai Province, the occurrence frequency of heavy frost reduced and the intensity weakened; the intensity variation of spring frost was more obvious than that of autumn frost; and the climate warming mitigated the autumn frost damage and enhanced the spring frost damage.

Abstract:Based on the analysis of meteorological conditions during the growth and development of grasshoppers in Inner Mongolia, the key physiologicalmeteorological factors at the main growth and development stages of grasshoppers are selected to construct the meteorological suitability index of grasshoppers which is used to predict the meteorological grades for the growth and development of grasshoppers. The average prediction accuracy of meteorological grades is 68%. Through calculating the meteorological suitability index and predicting the meteorological grades for the growth and development of grasshoppers, based on the meteorological data from meteorological stations over the grassland in Inner Mongolia, the spatial analysis of the meteorological conditions and the growth and development of grasshoppers can be made. The application proved that the index is simple, convenient, and useful in operational service.

Abstract:The meteorological conditions for grasshopper disasters from 1980 to 2004 in Inner Mongolia grasslands are studied. Results indicate that droughts in summer and fall and winter warming are advantageous to the survival of the overwintering grasshopper eggs, and the snow cover in winter can protect the eggs, but heavy snow at the end of spring would be fatal to grasshoppers. Rich rainfall in spring and gradually increasing temperature are favorable to the hatchability of grasshopper eggs. The emergence rate of nymphs can be reduced evidently when temperature drops strongly during the embryo and growth stages of eggs as nymphs cannot endure cold waves and heavy frost. After entering the fourth larval instar, grasshoppers begin to have the ability to avoid adverse conditions. The meteorological conditions before the growth stage of overwintering eggs and embryos and the third instar of nymphs have significant influence on the largescale outburst of grasshoppers, and thus can be used as good indicators in the early warning of grasshopper disasters.

Abstract:The variation characteristics of the main meteorological restricting factors for and the influences on apple production in the 4 northern counties of Yan’an are analyzed by means of the local meteorological observation data. The results indicate that there was an increasing tendency in temperature in the 4 northern counties of Yan’an since 1986, especially after 1997. From 1997 to 2005, the annual average temperature was 8 ℃ higher in Wuqi, Zhidan, and the over10℃ accumulated temperature is over 3200 ℃, being a relative warm period, in which the temperature meets the needs of apple growth and development; besides the midApril, the minimum temperature of each dekad in spring rose; the number of freezing injury occurrence in the flowering period reduced by half, and the freezing damage occurred mainly in the bud stage; there was much more precipitation in the 1960s’, with the mean annual precipitation of Wuqi and Zhidan being over 500 mm; the rainfall decreased slowly after 1968 with the minimum in the 1990s’; after 2001, the precipitation increased, but still cannot reach the suitable level for the growth of apple.

Abstract:The characteristics of interdecadal variation of highrisk forestfire periods in spring in Heilongjiang Province are analyzed by using the observation data from 29 stations of Heilongjiang Province from 1961 to 2006．The results indicate that the highrisk forestfire periods in spring in the western and southern parts of Heilongjiang Province are longer than those in the eastern and northern parts. The highrisk forestfire periods in spring have obvious interdecadal variability with the most rapid lengthening in the 1990s, but there are some differences among various areas, with the lengthening in the southwestern and eastern of Heilongjiang Province beginning from the 1970s．Moreover，the climatic background of interdecadal variability of the highrisk forestfire periods is also discussed preliminarily. The interdecada1 variation of highrisk forestfire periods in Heilongjiang Province from the 1990s may be related to the global climate warming and the interdecadal variation of atmospheric circulation systems.

Abstract:Through analyzing the data of lowtemperature and overcast weather processes from November to next March from 1998 to 2007, it is found that the 500hPa circulation patterns during continual overcast weather (snow, fog) in Hebei Province can be divided into three types on the Eurasian region from November to next March for each year: cold vortex, trough, and highpressure. As a example, the disasterinducing environment and the vegetable growing state in greenhouses during the process of lowtemperature and overcast weather in January 2001 are analyzed.

Abstract:Soil moisture is a key variable in water and energy exchanges in landatmosphere interface. The passive microwave remote sensing is the most potent technology to retrieve soil moisture. A brief introduction is made to microwave theory, and a general review of soil moisture retrieval algorithms is given. Three typical cases are illustrated based on the different microwave sensors by comparing various algorithms, which correspond to the threeparameter AMSRbased retrieval developed by Njoku and Li, the twoparameter SMMRbased retrieval developed by Owe et al. and the twoparameter SSM/Ibased retrieval developed by Wen et al. The insufficiency and potentials in the researches on soil moisture are discussed.

Abstract:The recent development status, scientific missions, system configuration, progresses and future development trend of international GNSS occultation projects, including GPS/MET, Orsted, Sunsat, SACC,CHAMP, GRACE, FedSat, COSMIC, METOP and ACE+ projects, are introduced in detail. It is pointed out that occultation sounding technology has made great progress in operational application since the implementation of GPS/MET project. The development of GNSS occultation sounding will turn to the multistar integration, and the international cooperation in the development among projects will become a trend in the future.

Abstract:An objective data processing method is presented for the calibration of sun photometers CE318 manufactured by the CIMEL Company (France) by using the Langley method and conventional observation data. There are four steps: (1) the observational data from sun photometers are processed with the Langley method in order to acquire calibration coefficients, the linear fitting correlation coefficients for the Langley method, the aerosol optical depth at 550 nm and so on; (2) calibration coefficients are screened through three thresholds: correlation coefficients at 440 nm （≥0.99）, aerosol optical depth at 550 nm （≤0.15） and the number of data sets for linear fitting in 12 hours （≥8）; (3) calibration coefficients are screened again according to voltage signal images and the maximum at noon; (4) the annual mean calibration coefficients are obtained from the remain data. The data from four sun photometers at Urumqi, Tazhong, Hotan and Hami in Xinjiang from 2002 to 2005 are processed according to the above four procedures. The final mean calibration coefficients are compared with the calibration results acquired through intercomparison with the reference sun photometer in Beijing in 2005 and standard coefficients provided by the CIMEL Company. Biases in these data at three sites are all less than 8.5% (except for the error of Hotan Station), which shows that the procedures for calibration are feasible.

Abstract:By means of the atmospheric precipitable water vapor data measured by groundbased GPS at Shijiazhuang and Zhangjiakou, a comparison is made between the radiosondecalculated and the GPSretrieved precipitable water. A severe precipitation case occurred in the southern Hebei Province in July 2007 is analyzed. It is found out that the GPS retrieval of precipitable water, which is slightly greater than the radiosondederived, is more reliable and useful; the results of the two methods have accordant variation trends. For the single station, there exist certain limitations in the effective radius of the GPSretrieved perceptible water.

Abstract:Based on the method for estimating the noiselevel in power spectrum from wind profiler radar, the spatialtemporal variation of the environmental noiselevel for the WPRs (CFL08) radar at Yanqing, Beijing, is studied statistically by means the sounding data of October to December 2006. During the observation, the environmental noise decreased with the increase of height under 5 km altitude, and the average environmental noise in October was stronger than those in November and December. Two methods for calculating the atmospheric returnsignal power for wind profile radar by SNR (SignaltoNoise Ratio) are presented, and the corrected results are almost the same.

Abstract:The wind speed measurement at automatic weather stations usually adopts only the singlechannel acquiring and processing circuit. In order to achieve the multichannel simultaneous wind speed measurement, the multichannel measurement of wind speed is studied, and the characteristics of the hardware circuit design based on the interrupt controller with the software for interrupt counting are described. The 8channel simultaneous wind speed measurement can be realized with the method. The relationship between system MCU (Microprocessor Control Unit) operating speed and interruption codes is analyzed, and the longest executive time allowable for an interrupt routine is calculated. This method not only can be used to avoid the interruption count lose, and but also play a very good role of antiinterference. On the basis of the appropriate additional hardware and software optimization, it can be extended to 16channel simultaneous wind speed measurement. The hardware schematic chart and some source codes are given. This measurement method is successfully put to use in the MultiChannel Wind Observing System developed by the Guangdong Atmospheric Detection Technology Center, as well as in other institutions across China, and the trial application shows that it is feasible and practical.

Abstract:An introduction is made to the observational experiments on solid precipitation at the Changchun station of Jilin Province, Tonghe station of Heilongjiang Province, and Daxigou station of Xinjiang Province from January to September in 2006. There are three types of sounding apparatuses (21 in total) from six manufacturers participated in the 9month experiment. The experiments used the Double Fence Intercomparison Reference (DFIR) recommended by WMO (1985) as the standards. Through the experiments, the characteristics of tippingbucket gauges, weighingrecording gauges, laser precipitation monitors in measuring different type precipitation were tested, which provide a basis for the selection of the automatized observational equipment on solid precipitation and the operational service promotion of solid precipitation.

Abstract:Using the lightning data from 2004 to 2007 from the Jiangxi Province Lightning Monitoring and Positioning System, an analysis is made of the distributional characteristics of lightning intensity and steepness in Jiangxi Province, as well as the correlative coefficient between them. According to the related lightning protection criterions for building structure design (5005794), some thunder and lightning parameters and the formulas for calculating the safe distance are discussed. The analysis indicates that there is remarkable difference between the annual mean density of lightning strikes calculated from the measurements and from the observed number of thunderstorm days.

Abstract:A statistical analysis is made of the air pressure and geopotential height variation measured by means of the Lband Radar and Radiosonde Sounding System and GTS1 at the Minqin station. The results indicate that the measurements are lower than standard values when the sensors are under the stable environmental condition; when pressure difference is 1 hPa, the height differences produced by the Lband Radar and Radiosonde Sounding System increase with the increasing height; the comparison of the Lband radar and GTS1 measurements show that height differences increase with the ascending radiosonde gradually, being 1700 m at the sounding height of 36000 m.

Abstract:Based on the rainfall data from AWS (Automatic Weather Stations) and the village and townlevel automatic precipitation stations, the Meteorological service, Monitoring and Autoalarming System was developed. Taking the database as the core, this system, by means of the basic meteorological service communication network and the client/server pattern, realized such functions as the regional areal precipitation appraisal, the monitoring of data gathering from village and townlevel automatic precipitation stations, the autoalarming of rainfall intensity according to the precipitation grades in the specified time periods, the realtime storage of AWS data, and the autodrawing of various color meteorological charts, etc. An introduction is made to the system structural design, the objectives of various subsystems, and the principles and methods for realizing various functions.

Abstract:The surface meteorological observation data file (File A) is a text file, which contains raw observation data of a month, including four parts (station parameters, observation data, quality control and additional information). The observation data consist of 20 surface elements with each having different record formats according to the type of the station and observation method. Because of its multiplicity and complicacy, the data file is inconvenient to use directly. A transformation system of surface meteorological observation data files based on VBA and the detailed procedures of data transformation is developed. It can be used to import File A into Excel in bulk for the data observed at different times and with different methods so to improve working efficiency.

Abstract:A rainfall count software is devised with the C++ Builder language, in which every signal count represents 0.1 mm and is written into a database, realizing the automatic acquisition of the precipitation measured by tippingbucket remote raingauges and the realtime display of the precipitation on that day on the Web. This technique has been successfully used on the Web site of the Quanzhou Meteorological Bureau (www.qzqxw.com) and received satisfactory results.

Abstract:The principles of the DY01 power system used in the automatic weather station CAWS600B(S) are introduced, and the rectifier and filter circuit, central control circuit, charging and stabilizing circuit are analyzed. The typical failures which may happen in various parts of the circuits are discussed and the corresponding detection and maintenance methods are presented, which are helpful to the maintenance of automatic weather stations across China.

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