Abstract:Atmospheric pollution has been the focus for the global environment ch ange. The traditional groundbased monitoring of the atmospheric pollution can not satisfy the demand of science research and decisionmaking of government. Th e technology for trace gas remote sensing based on the satellite monitoring has p layed an important role in pollution monitoring, which can get the temporal and spatial variation of pollution in longtime series and the trend of the [JP2]tr acegas change.So the study of global biogeochemical cycle and climate chang e can be done with these technologies and data. The instrument for trace gas monitoring on satellite and the data processing were reviewed. The p rospects for trace gas remote sensing by our own satellite instruments and the t race gas research projects are also outlined.

Abstract:Areal Precipitation is an important parameter in Hydrometeorology. The e stimatio n and prediction of areal precipitation are directly concerned with the accuracy of flood forecast and the decision making for flood dispatching. Owing to the c omplexity of spatial pattern of rainfall, how to accurately estimate areal preci pitation still remains a scientific problem. Traditionally spatial analysis tech niques are applied to regular precipitation data to estimate the areal precipita tion. With the development of nonregular observational technologies, areal pre c ipitation estimation based on data assimilation of radar and satellite data comb ined with automatic raingauge data has been the trend of areal precipitation est imation technology, while integrated management of data analysis and display bui lt on GIS has been the mainstream of the operational system of area rainfall est imation. Through the comparison between hydrologic simulation and observation, t he estimated areal precipitation can be indirectly validated.

Abstract:conversion of water substance in clouds, and precipitation efficiency were simulated. The model simulation declared that plen tiful vapor inflow provided a favorable condition for the formation and developm ent of clouds. The inflow of vapor in the Henan region was mostly horizontal wit h weak contribution from surface evaporation. The main vapor inflow exists in th e southern and western sides of Henan with the strongest inflow at about the hei ght of 2 km, whereas the eastern and northern sides are main vapor outflow. The average height of 0℃ layer is about 2.5km. The clouds have a distinct verti ca llylayered structure with ice cloud above 6 km, waterice mixed cloud betwee n 2.5～6km, and liquid cloud below 2.5km, which accords with the “seeder feed er" cloud structure. The horizontal flow of hydrometeor was weaker compared with the vapor flow. The growth of precipitating ice particles mainly occurs at about the height of 4km, and that of rain droplets at about the height of 2.5km, where is near the zero temperature level. The temporal change of regional hourly preci pitation efficiency is consistent with surface hourly precipitation with a disti nct lag behind the vapor inflow. During strong precipitation, regional hourly pr ecipitation efficiency is 20%～30%. The distribution of regional precipitation e fficiency is consistent with total precipitation with higher value in the southe rn Henan and lower value in the north.

Abstract:Based on the Hu Zhijin and Liu Qijun's cloud physics scheme, a new towmoment m icrophysical scheme is developed and incorporated in the GRAPES model.Using the mode which contains the new cloud physics scheme, a mountainous area cloud and precipitation process in the Qilian Mountain region is simulated. The microstruc ture of mountainous area cloud is studied and a numerical simulation on cloud se eding is conducted. The main analysis results are as follows: (1) The GRAPES mod el with twomoment scheme is able to reveal the distribution of precipitation, intensity and cloud field; (2) The new scheme can give reasonable microstructure of cloud system in the Qilian Mountain region and indicate its so me characteristics; (3) The artificial ice crystals seeding can lead to the increasing of precipitation, and the distribut ion of rain enhancement in the initial stage of cloud is wider than that in the development stage of cloud; (4) Dynamical structure of the cloud has some change s after seeding.

Abstract:GRAPES_TCM2.6(GT2.6), the updated version of the numerical model G RAPES_TCM2.1（GT2.1）, is used to postforecast tracks of TCs occurred over the Northw estern Pacific and the South China Sea during 2005. A series of detailed perform ance verifications for the numerical prediction of tropical cyclone tracks is pr esented. The results show that GT2.6 has a goodperformance on TC track pr ediction. The total mean forecast errors (MFE) at 24, 48 and 72h are 135.8, 230. 7and 336.0km, respectively. The result also shows that the MFE at 12h is somewha t large (about 100km). The significant improvement of GT2.6's track prediction f or the turning TC can be obtained through the modification of the forecast track s with systematic bias. The model is found to have very good forecast skill for the cases that occurred in the west of 130E, especially for those close to the s outheast of China. In general, the forecast track of GT2.6 is faster (slower ) b efore (after) 48 hours than the optimal track, and the speed bias at 12 hour is larger during the forecast period (approximately 1m/s). In comparison with GT2. 1, GT2.6 has similar performance stability and MFE characteristics on 048h TC t rack prediction, except that the 48h forecast of GT 2.6 is significantly better than that of GT 2.1.  Primary results indicate that several essential measures should be taken to furt her improve the track forecast skill of GT2.6. They are replacing the vortex-env ironment separation scheme with a stricter one, adding persistence vector to imp rove the initial motion and an asymmetric bogus vortex in the initial time, as w ell as enlarging the forecast domain and properly setting its position. 

Abstract:A BackPropagation (BP) Model of Artificial Neural Network (ANN) is used for th e partitioning of radar reflectivity into convective and stratiformcloud preci pitation classifications with the CINRADSA data from 2001 to 2003 in Hefei. Th e trained ANN is applied in a precipitation process. It is proved that the singl e hidelayer BP model of ANN can be used to classify the different precipitatio n echoes with a high successrate. It is also validated that: the successrate is influenced by following factors: the amount and the inputorder of the tr ainingdatabase, the nerve cell number of the hidedlayer and the choice of th e learning rate.

Abstract:Typhoon Maisha(0509) moved northward after landing on Zhejiang. Beijing Meteorol ogical Observatory predicted that the typhoon would bring heavy rainfall to Beij ing. Actuall y, there was the heavy rain only in the northeastern Beijing and the moderate ra in in the most of the city. To understand typhoon heavy rainfall in Huabei deepl y, an analysis of this unsuccessful forecast is performed by using the conventi onal meteorological data and the satellite images. The results show that (1) the numerical forecast of the typhoon track had an error, (2) the typhoon maintain ed asymmetry structure and heavy rain occurred only in the east and north of the typhoon, (3) the weak southeast jet occurred mainly in the east of 120°E and (4) since Huabei high pressure obstructed cold air from the great band of Yello w River moving eastward, the interactionbetween lowlatitude and middlelatitude synoptic system could not formed. In addition, it provides some instructions for the forecast and service of typhoon heavy ra infall in Beijing. 

Abstract:Tropical cyclones (TCs) over the Northwestern Pacific and South China Sea, of wh ich wind velocity exceeds grade 8, are statistically investigated for the period of 1949—2005. Results show that 27.47 TCs occur annually over those regions, with 6.89 TCs landing over China. Both of the numbers in recent 10 years are bel ow the mean of 1949—2005. The most preferable time period for the generation an d landing of TC over China is July to September. The South Coast of China is the location of most landing TC(s). Most coast regions of China, such as Northeast China, North China, Yellow River Huaihe River basins, south to the Yangtze Riv e r, South China and the eastern Southwest China and so on, have the chance for he avy rainfall of typhoon. Southeast coast of China is featured by the highest pos sibility of TC heavy rainfall. The maximum is found over Hainan Province and the east coast of Guangdong Province, the second over the coast of Guangxi Province and southeast coast of Fujian Province. The spatial pattern of frequency in TC heavy rainfall provides the background information for the forecast of landing T C rainfall.

Abstract:Based on the conventional and singleDoppler radar data，the heavy snow event o ccurred in the North China on 6th February 2006 has been analyzed. The results s how that the major influencing system of this heavy snowfall is the wellmatche d configuration of the trough at 500hPa, the herringbone shear at 850hPa and the cyclone at surface. The Doppler radar data analyses show that the appearance of the mesoscale inverse shear at 0.7～1.1 km, as well as the establishment an d downward stretch of the southwestern jet at 4.8km accelerated the wind convergen ce and thickening of the convergence layer, which provide favorable condition to the heavy snowfall. The timings of the mesoscale inverse shear and t he southwestern jet correspond well to that of the appearance and maintenance of the heavy snowfall. The cold front also affects t he maintenance of the snowfall. We applied the improved EVAD technique to dynami cally analyze the changes of the average divergence and vertical velocity at dif ferent snowfall periods. The results indicate that the appearances of the meso scale inverse shear and the cold front correspond to the intense convergence and upward motion, which cause the occurrence and maintenance of the snowfall. Thes e further confirm the existences of the mesoscale inverse shear and clod front , as well as their correspondence to the heavy snowfall.

Abstract:The Tibetan Plateau is one of the best places to investigate global clim ate changes. Aridity or humidity of land surface has been paid more and more att ention by scientists and publics. On the basis of the mean annual air temperatur e, precipitation and relative humidity from 25 meteorological stations in the Ti betan Region from 1960 to 2001, the longterm trend of major climatic variables was analyzed by using MannKendall test method. The results showed that the ai r temperature, precipitation and relative humidity all exhibited an increasing t endency, and the MannKendall slopes are 0.31℃/10a, 0.96mm/a and 0.3%/10a, res pectively during the past 42 years. Over the Tibetan Region, the increases in 〖 CM(18〗temperature and humidity occur mainly inautumn, also occurring in spring; increase of temperature and a little decreasing humidity happen in summer. The increase of temperature is remarkable but relative humidity shows no increasing tendency in winter. The MannKendall test results showed that the air temperature exhibited an increasing trend in f our seasons, especially in winter. Summer contributed the most for the decreasin g trend of annual precipitation. Precipitation in summer exhibited a decreasing tendency. Relative humidity showed a declining trend in summer as well.

Abstract:Based on the meteorological data from 6 observational stations in Hami, Xinjiang during 1961-2005, characteristics of air temperature, daily range, hot day and cool day were analyzed. In order to find the relationship between the tempe rature and other weather conditions, precipitation and cloud fraction were also discussed. The results show that the temperature has increased remarkably in Ha mi area in recent 45 years, with the most obvious [JP2]warming occurring in sum mer, but the warming trends in spring were weak. The warming was the most re markable after the 1990's, and the largest increase range appeared in recent yea rs of the 21st century. Similar to the average temperature, the maximum and min imum temperature had increasing trends. The reason of obvious decrease in da ily range was that the extent of warming in the minimum temperature is larger th an that of the maximum temperature. Under the global warming background, the hot days were increasing but the cool days decreasing. There was some difference in the warming trends in several stations. The possible reasons of the difference are related to the increasing of the precipitation and cloud fraction and the re ducing sunshinehour. Moreover winter average air temperature of Hami jumped in the 1980's, and the jumping time was 5 to 6 years later than that in the other a rea of Xinjiang. Therefore, there were differences in the climate jump in diffe rent area.

Abstract:With the development of wind electricity, wind resource simulation over complex terrain is becoming an important question for discussion. On the basis of wind o bservational data of one year of 9 observation towers at 22 levels in the southe rn zone of a certain coastal island of Guangdong Province, and the digital terra in data with high resolution of the island ,wind resource microscale simulatio n by multiple regression was done. In addition, the simulated result was compare d with that obtained by WASP program. It was found that:(1) There is a significa nt correlation between annual mean wind speed and geographical spatial factors;( 2) The mean relative errors of simulated annual mean wind speed and wind power d ensity are 3.2% and 3.5%, respectively; (3) The assumption test shows that there is a good effect in annual mean wind speedsimulation at those sites without observational data;(4) The distribution of th e wind resource is basically consistent with that obtained by WASP program.

Abstract:According to the breeding behavior of bollworm, its anniversary activi ty can be divided into four phases: the Pupa in autumn, overwintering, eclosion in spring and damage in summer. For each phase, by selecting some me teorological parameters which is of entomological and statistical meaning a mult ieffectiveness normalized meteorological prediction model of bollworm and anal ysisevaluation indices are developed by normalized processing and weighted com bination of parameters. It shows that occurrence of bollworm is closely related to the meteorological conditions. The complex correlation coefficients of each phase are 0.778-0.878, with the fit of 96.7%. The model has a good result i n the practice.It concludes that the nondimensional proc essing of meteorological parameters is not only favorable to its combination ea ch other, but also to increase the precise of model prediction. However the bio logical meanings of these combination parameters are to be defined through biolo gical experiments.

Abstract:In order to add new MeiYu season sample in the MidLower Reaches of t he Changjiang River, the daily data of reanalysis from NCEP/NCAR and the precipitation observation of 5 stations i n the MidLower Reaches of the Changjiang River are used and some routine met hods based on circulation consideration are adopted to diagnose the characteristic parameter of summer MeiYu period in the MidLower Reaches of the Changjiang River in 2006, and to discuss the relationship between MeiYu season and summer monsoon in that year. The result shows that it is reasonable to ensure th at the beginning and ending MeiYu season in the MidLower Reaches of the C hangjiang River are the 5th pentad of June and the 4th pentad of July respective ly, also the total MeiYu precipitation of 2006 is below the normal due to the weaker Indomonsoon and east Asia mons oon (including summer the South China Sea monsoon and summer subtropical monsoon) o f that season.