Abstract:Major advances in studies of summer low temperature, such as its climatic features and its circulation features as well as the influence factors in Northeast Ch ina for recent 30 years are reviewed. Summer low temperature in Northeast China is a largescale climatic disaster which can persist longer and be influenced b y atmosphere general circulation systems and underlying surface. The studies of forecast for summer low temperature are simpler, so the mechanism and developing forecast system of summer low temperature in Northeast China will be most impor tant in the future studies.

Abstract:At the Engineering phase of Application System Project of FY-2(02) Geos tationary Meteorological Satellite, according to the general requirement of Data Processing Center, the application of software reengineering in the Data Proces sing Center of FY-2 series was described. Through a series of engineering proce ss, such as reverse engineering, restructuring of code, data and document etc，the software of data and product processing in advance study phase of FY-2(02) was rebuilt for productoriented and processingoriented flow, the common service w as obtained, the processing flow was simplified, furthermore, the elaborate docume nt was archived. After reengineering the application software of DPC data and p roduct processing system met with the multirequirements of ground application system of FY-2(02), such as highreliability, maintainability and real time, e tc.

Abstract:Using the fifthgeneration PSU/NCAR Mesoscale Model (MM5V3.7), a rain storm on June 25 to 26, 2005 in Henan Province is successfully simulated. The output of the model such as integrated hydrometeor, the Doppler Radar echo, and the 24ho ur precipitation are very the same like the fact. Based on the good res ults of the model, the dynamic and thermodynamic conditions, the changes of the i nstability index in two different areas and the hydrometeor changes are analyzed . Besides, the differences of the microphysical structures characteristics in the different phases of the precipitation process are analyzed by using the quality content of snow (Qs), graupel (Qg), ice (Qi), rain (Qr), and cloud water (Qc) calculated by Reisner microphysical schemes.

Abstract:Based on the new generation numerical prediction model GRAPES (Global/ Regional Assimilation and Prediction Enhanced System), with three kinds of physi cs option parameterization schemes(Kessler schemes、NCEP3－class simple ice sc hemes and simple ice schemes (developed by Liu Qinjun, CAMS) ) and two kinds of cu mulus parameterization schemes (KainFritsch (new Eta) and BettsMillerJanji c), six combinational schemes are formed. 48hour predicting experiments are made for the precipitation cases in the rainy season in Guizhou. Comparisons among the experiments and analyses of the observations indicate that GRAPES model can be used for predicting Guizhou precipitation. The predicting effect of cumulus para meterization schemes is better than that of physics option parameterization sche mes. The predicting Guizhou precipitation ability of combinational schemes with simple ice scheme physics option parameterization, BettsMillerJanjic cumulus parameterization is superior to the others. These results are useful for improvin g the GRAPES model for predicting Guizhou precipitation.

Abstract:To make fully use of FY-2C geostationary satellite in the field of wea ther modification and climate, cloud effective particle radius was retrieved fro m FY2C Channel 4（3.5～4.0μm）data based on the radiative transfer mode, SBDA RT. While comparing to the corresponding MODIS products on TERRA, it is shown tha t FY-2C presents similar distribution patterns of cloud effective radius to MOD IS, but with some differences in particle size. The different retrieval algorithm s, satellite resolutions and channels may be the main factors causing these diff erences between two data sets.

Abstract:An important step in deriving winds from geostationary meteorological satellite data is selecting the clouds which move slowly and go with the wind，w hich is called tracers. A new scheme of tracer selection is developed to improve the quality and the density of cloud motion winds. The scheme has a novel featu re that the extraction location of the tracer is not fixed at the center locatio n of the grid, but first optimized at the location where the gradient is maximum in the grid domain, and then by cumulonimbus and uniformity test, the final tra cers can be decided. Then cloud motion winds are derived from these tracers and after a circumfluence analysis on the cloud motion winds, the cloud motion wind s are compared with the rawinsonde winds. The result shows that the cloud motio n winds have well quality and higher density, and the wind structure of weather system can be seen clearly from them.

Abstract:Based on rainfall observation and daily NCEP/NCAR reanalysis dataset from June t o July in 2005, a comparison of three dimension structures of subtropical high for two regional heavy rainfall events is carried out with characteristic index method and physical diagnosis analysis. The result shows that the subtropical hi gh structure for the two events have different properties, i.e. thermal or dynam ical. This has led to difference for these two events with respect to moisture t ransport condition and large scale background for vertical motion.

Abstract:The stream function and potential function of water vapor transport vector dur ing a heavy rainfall in the Huaihe River valley in the summer of 2005 is studied and the averaged water vapor budget is computed and diagnosed during the event period. The results indicate that the main water vapor source of the event is the strong vapour transportation band coming from Philippinesand across South China Sea and arriving to the middleeast China. This strong vapor tran sportation was composed of two branches. The first one was from Pacific vapor tr ansport center and it moved westward along the south region of equator. The othe r one was coming from the easterly trade wind in the southern hemisphere which got across the equator at Africa's Somalia peninsula and then arrived to the nor th of Bangal Gulf, and finally reaching to Philippines. The area of severe vapor transport vector converge corresponds with the area of the heavy rainfall. The total water vapor budget corresponds with the average rainfall, the average rain fall increases with the increasing total water vapor converge. On the other hand , the water vapor vertical transport at low level corresponds well with the avera ge arearainfall.

Abstract:Based on the NCEP reanalysis data and T213 data, the two typical heavy rainfall which occured in Sichuan and Chongqing in summer,2006 was analyzed. Th e result shows that the variation of 500hpa circulation, and the intrusion of co ld advection at upper air and the cold air at low level are favorable to the occ urrence of the heavy rainfall. On the other hand, the strengthen of the low leve l jet, wind speed pulsation are key to the heavy rainfall. The intensity and loc ation of the heavy rainfall are related to the convergence of water vapour in 85 0hpa, divergence at high level and the strengthen of the ascending motion。

Abstract:Based on the analysis of the potential vorticity(PV) on isentropic su rface in the three phases of regional rainstorm in Henan Province caused by Typh oon Haitang, the mechanism for the generation of the rainstorm is disclosed. The results show that typhoon is a system with high PV value, the first rainstorm p hase is generated in the south to the southeasterly jet stream which lies in the northeastern part of typhoon. The second and the third phases are the rainstorm s far from the typhoon. They occur because of the interaction of typhoon and col d air with high PV when typhoon reaches the relatively high latitude. In additio n, the southward shift of upper level jet stream is advantageous to the southwar d transportation of high value PV and can promote the intensification of rainsto rm.

Abstract:With conventional meteorological data as well as NCEP/NCAR reanalysis data, the processes of the typhoon 9711 and the typhoon Matsa (0509) are diagno sed and compared.　The result indicates that the restrengthening of the typhoo n 9711 after its denaturing was due to intense development of a frontal cyclon e, which was incarnated by downwards moving of the upper level potiential votici ty, the tropical low pressure circulation and the lowlevel front. But in the p r ocess of the denaturing of the typhoon Matsa, there was no lowlevel front, and the atmospheric slanting piezotropy was weaker. So the mutual influence of downw ards moving of the upper level potiential voticity, the tropical lowpressure c irculation and the lowlevel front did not exist. MPV1<0 and MPV2>0 were characteristic storm rainfall area, which is a good denotation of this kind of rainstorm. Downwards moving of the upper level potiential votic ity is advantageous to releasing of the unstable energy, and causing the increas ing precipitation.

Abstract:Using the NCEP grid 1°×1° data and convection observational data, The vertica l helicity was applied to analyze heavy rainstorm processe, which occurred in Ju ne, 2005 over Guangdong. The results of diagnostic analyses show that both the r apidly strengthening trend of the value in positive center of the vertical helic ity at lower level and the rapidly lessening trend of the negative one at upper level during the rainstorm can reflect the position and intensity of the heavy r ainstorm in Guangdong. When the value in negative center of hp at upper level ra pidly reduced and the positive one at lower level rapidly increased, and when th e region of both the positive helicity center turning strong and the negative on e turning poor overlapped near t he same longitudeor latitude, the rainfall over the corresponding region reached the maximum and the intensity of the rainstorm reached the strongest. During the heavy rainfall which is never suffered in a c entury in Longmen and the most heavy rainfall days in Guangdong, positive vertic al helicity center at the lowerlevel troposphere and negative one at the uppe r troposphere tends downwards to the lowlevel.

Abstract:Based on the daily 500 hPa geopotential height from realtime database of National Meteorogical Information Center, the Northern Hemisphere and key re gions blocking high monitoring and diagnostics technique which fits for operatio n was selected. Using the blocking high index, realtime blocking high monitori ng over each longitude at the midhigh latitudes in the Northern Hemisphere was achieved. Key regions in Okhotsk, Baika and Ural, which can affect on summer pre cipitations in China, were selected for blocking high monitoring. Meanwhile, dai ly and 5days running mean general circulation patterns of 500 hPa in the North ern Hemisphere were both monitored. Thus, the realtime operational system of m oni toring and diagnostics for the Northern Hemisphere blocking high was set up. Thr ough the analysis of blocking high monitoring products of 2006, the monitoring r esults accorded with the fact, including the blocking intense and location. These products were helpful for summer precipitation prediction of China.

Abstract:Based on domestic and foreign shortterm climate forecast quality appr aisal method at the present stage, according to operation development needs, a n ew quality appraisal method for shortterm climate forecast was put forward. th e nearly 10 years shortterm climate forecast results for Liaoning Province sinc e 1994 were evaluated objectively by using the new method. By contrast with the o riginal appraisal conclusion, the results show that the new method is superior t o the original one, and can well reflect the level of current shortterm climat e forecast.

Abstract:Under the case of the artificial low temperature and drought, the lea f fluorescence parameters (Fo, Fm, Fv/Fm) and Photosynth esis rate are determined . The results show that the low temperature or drought decreased photochemical c onversion effect, their relationship can be expressed as follow:Y=0.002X2-0.0055X+0.8032 There: Y is photochemical conversion effect; X is tempera ture. The low temperatu r e decreased photosynthesis rate. The photosynthesis rate decreased by 27.8% when temperature decreased from 25℃ to 15℃.When the soil moisture decreased from t he treatment 5 to the treatment 1, during different temperature Photochemical conversion effect decreased by 1%～8%, and Photosynthesis rate decreased by abou t 80%. The negative effect of the low temperature combining with drought on phot ochemical conversion effect and photosynthesis rate was far greater. The decreas ing scale of photochemical conversion effect reaches 2.5 times, and the photosy nthesis rate was increased by about 15%. The photochemical conversion effect and photosynthesis rate was remarkable positive relation.

Abstract:Based on the monthly precipitation date from 2 stations in the South of Shandong Province, the se cular variation tendency of precipitation and the drought frequency are analyzed with the accumulated anomalous, skids the ttest and KruskalWallis assay metho d. The results show that there is a evident decrease of the precipitation in the south of Shandong Province since 1950s, and a sudden change spot in the mid 197 0s. After the chang spot, the precipitation reduced above 12%, especially in the rainy season, the precipitation reduced remarkably, above 16%. The dry season p recipitation change was not remarkable. The droughts all happened after the sudden change spot. The dry season frequency and their intensities obviously increas e since the sudden change spot. The frequencies of the 3 dry month are high and the periods of continuous droughts are obviously long.

Abstract:On the basis of the 9month observational data from five representative AWS in 2005, daily extremum distributions of main meteorological elements were obtained by the statistical method. Calibration period of various meteorological element s is studied by analyzing calibration time span and data transmitting schedule. The results show that the optimal calibration period of various meteorological e lements is as follows: humidity:8:00-11:00, fleet soil temperature:14:00-17:30, deepseated soil temperature:8:00-11:30, wind direction and wind speed:8:00 -9:3 0 or 16:30-18:00, barometric pressure:11:00-12:30,evaporation:8:00-8:30 or 17:30 -18:00. These results will help to revise the schedule of onthespot calibra tion of AWS, and reduce the influence of calibration operation on AWS observatio n.

Abstract:In 2006, sea surface temperature (SST) in CentralEast Pacific of equator was u ndergoing from cold phase (LaNina condition) to warm (ElNino). At 500hPa geo potential height, it prevail meridional circulation in the midhigh latitude ov er EuroAsian area in early winter, but zonal circulation was mainly exhibited over Asian area in late. In summer and autumn, the circulation appeared meridion al in the high latitude and zonal in the middle latitude over Asian continent, t o result in the most warming in summer and autumn in China. In summer 2006, subt ropical high was stronger, and the position was northward and westward than norm al. Asian summer monsoon was stronger than normal. There was no obvious and pers ist blocking in the northeast Asia. The Meiyu in the midlower Yangtze River wa s weaker. Heating resource over QinghaiXizang Plateau was higher from winter t o autumn. Convective activity in warm pool of west equator Pacific is stronger i n July, August and October.

Abstract:Global climate has been warming up persistently in 2006 , and it is t he sixth warmest year on record. An El Ni[AKn～D]o event came into being since A ugust 2 006. In January, strong clod wave and snowstorm raided most of Europe and Japan. During summer, heat wave swept part of China, most of USA and Europe. In the ye ar, drought and flood occurred in many regions in the world, such as southern US A and southeastern Australia suffered severe drought, drought and flood occurred in eastern Africa in turn, rainstorm attacked southern Asia and northwestern So uth America frequently. In 2006, the activities of typhoons were weaker than nor mal in the northwestern Pacific, but stronger and more destructive than normal. Meanwhile, the activities of hurricanes were weaker than normal in the Atlantic Ocean and stronger than normal in the eastern North Pacific.

Abstract:The annual mean temperature of China in 2006 was 1.09℃ above the clim atology (1971-2000 mean value). The year 2006 is the warmest year since 1951 (r e liable meteorological records). Meanwhile, the annual precipitation of China is slightly less than the climatology. The meteorological disasters occurred freque ntly in 2006. The economic losses and the number of people death caused by tropi cal cyclones were ranked as number one in all disasters, associated with the lar gescale crop and number of people suffering from the heavy drought. In general , the economic losses caused by the natural disasters in 2006 are the most since 1999.