Abstract:China is one of the countries that are most severely influenced by the meteorological disasters in the world. The meteorological disaster is more than 70% of the natural disasters in China. The economic lost caused by meteorological disasters is about 3%—6% of the GDP of China the average per year. To prevent and mitigate meteorological disasters, we must do two things: one is the monitoring and forecast of the meteorological disaster, and the issuing of the forecast and warning information of the meteorological disaster, the other is management in preventing the meteorological disasters.

Abstract:An advanced technique for partitioning tropical cyclone precipitation is studied. First, indices describing the differences between the subjective and objective partitioning precipitation are defined. Second, an idea for generating developing scheme was drawn up: changing the two important fixed parameters into variable parameters. Finally, the best scheme for the advanced technique is determined.Results show that the advanced technique has made a great improvement. Then, case verifications, especially with NOAA’s CMORPH data, prove that the advanced technique showed relative strong ability in distinguishing precipitations from two different TCs or a TC with a mid-latitude system.

Abstract:The generalized potential equivalent temperature θ_s can be considered as a new atmospheric parameter which contains vapor and liquid water in it. The physical significance of it and its extended application are further discussed by means of the concise derivation and demonstration. The concept of removal entropy index is proposed on the basis of the theory of dissipative structure. According to the characteristics of the generalized potential equivalent temperature itself, some parameters, such as the atmosphere liquid water content, the atmosphere water substance content,etc. are developed with these parameters, the very useful information for the forecasting of the severe convective weather and heavy rainfall can be provided.

Abstract:With the filtering method, the sub-synoptic scale and mesoscale informations of the atmosphere flow field are extracted. Then the horizontal wind field of large-and meso-scale are decomposited into barotropic component (vertical mean) and baroclinic component(perturbation) respectively. An analysis of the evolution of barotropic and baroclinic modes of sub-synoptic scale and mesoscale system in a heavy rainfall event in Wuhan during 21—22 July of 1998 is made. The results show that the evolution of barotropic component of the flow field of sub-synoptic scale and mesoscale is closely related to the brewing, development and disappearance of the event. The baroclinic component at 200hPa is strong, the barotropic component at 850hPa is strong, the baroclinicity is dominant. With the development of heavy rainfall, the barotropy will weaken while baroclinicity will get more strong, but the barotropy of current field in sub-synoptic sacle will get strong and the baroclinicity get weaken.

Abstract:The results of field experiment in 17—18 Dec.1997 and indoor little cloud chambers experiment conducted by Weather Modification Institute of Chinese Academy of Meteorological Sciences and Peking University in 1994—1995 are analyzed. It is shown that whether indoor or in the field, liquid nitrogen is an ideal catalyst because it obviously affects the visibility well. The microphysical structure observed at a site shows when successively seeding liquid nitrogen into the natural super-cooled fog whose horizontal visibility is 50—100m and number concentration is 1206/cm³, ice crystal will appear at the leeward side of the observation station about 4.5—5km after 35 minutes, it is mainly columnar, and its mean concentration is 0.35/cm³. The appearances of ice crystal disputed the stability of fog colloid structure, and changed the visibility well. When liquid nitrogen was seeded the second circle, wind direction turns to 210°—240°(NNW), no ice crystal appeared, concentration of fog drop decreased a little, small one decreased, and spectrum turned wide.

Abstract:During the season when the river water freezes or the river ice melts, ice flood disaster usually occurs in Ningxia-Inner Mongolia section of the Yellow River valley. Based on the meteorological and hydrological observations and NCEP/NCAR 6h analysis dataset of 1°×1°, the characteristics and causes of the disaster are analyzed by thermodynamic and dynamic methods. The results indicate that the disaster occurs under some meteorological, geographical and hydrological conditions. The freeze-up/break-up is related closely to the cold/warm air incursion and abrupt decreasing/increasing of temperature under advantageous large-scale circulation. The temperature advection and diabatic factor have an effect on the temperature change, while the intensity of the cold/warm air depends on the vorticity advection.

Abstract:Based on the improvement and supplement of GDCN1.0, a Global Station Climatological Daily Data Set (GSCDDS) is established for climate operation. The data set has the same spacial distribution as GDCN1.0. GSCDDS has more stations in China than GDCN1.0. The data set has good representative both in area and time coverage. Invalid values of temperatures are deleted by a designed quality control procedure.

Abstract:A brief introduction of AMDAR data application in Beijing Capital International Airport is given. Because of its high density in both the spatial and temporal, AMDAR data is very important in nowcasting and short-range forecasting in airports. Wind data from AMDAR were used to diagnose and detect low-level wind shear near the airport. AMDAR data can also used to detect the system moving.

Abstract:Based on NCEP 1°×1° 6h interval reanalyzed data and daily observation data, the circulation background, synoptic weather systems and the formation mechanism of the cold wave event covering the whole country on 10—13 March 2005 are discussed. The results show that the formation mechanisms of the event are as follows. (1) The strong warm advection of 500hPa over the west Europe led to a blocking high created in Siberia area, and a zonal though, the north-east stream in the north edge of the though led to super polar cold air and the cold air from west together and got to strengthen, and then the abnormally strong cold high, front zone, cold temperature center and cold temperature advection appear. (2) The two short-wave troughs moving eastwards intruded into the blocking high, which made the zonal trough created and became a meridianal one for two times, resulting in the strong cold air greatly moved into southern area. (3) The three conditions, involving the temperature sharp drop, the convergence of west-south jet stream and the cold air stream at 700hPa, and the vertical temperature distribution of the area below 0℃ above 1000hPa, provided the main factors of dynamics, moisture and condensation for severer snow in southern China.

Abstract:The characteristics of circulation and physical quantity of severe coldness in the late spring in Yunnan Province under Kunming Quasi-stationary front during the spring of 2005 are analyzed based on NCEP reanalysis data. The results show that the severe coldness caused by Kunming quasi-stationary front and the upper level shear are related closely to the evolution of circulation, humidity field and vapor transfer, if there is no southern branch trough. The moisture from the northern Burma is converged and uplifted at the middle and lower levels. All these results help to give physic basis of forecast this kind of severe coldness in late spring in Yunnan.

Abstract:A mesoscale analysis for the flash flood process in early summer of 2005 in Hunan Province is performed with the surface densified observation, rainfall data of automatic precipitation stations, FY-2C satellite TBB, Doppler-Radar data etc. The results indicate that the heavy rain occurred under the effect of mesoscale convergence line, mesoscale low and meso-α convective cloud clusters together. Suction effect with the divergence in the high level emerging earlier than that of convergence in the mid- and low-level, unstable stratification of the dry and cold air in the high and warm and humid air in the low in accompany with the bow pattern of θ_se profile and rich water vapor transport from South China Sea are the environmental conditions for the occurrence of heavy rain. Mesoscale systems which are corresponding with the activity of rain clusters can be clearly seen from the stream field after filtering. The development of cumulus and convection is earlier than that of mesoscale systems and rain clusters. Heavy rain is closely connected with the deep convective cloud clusters and convective cells with the strong radar reflectivity, high echo top and big VIL.

Abstract:Large-scale background, environment field and triggering, maintaining mechanism are diagnosed with the observation data and NCEP 6-hourly reanalysis data with resolution 1°×1°. The results show that erectness of coupling pattern between upper-layer jet and low jet and a divergence area, which came forth in right of upper-layer jet provide favorable surrounding conditions. It's vital for triggering the rainfall that warm and moist southerly airflow erupt from low layer to the upper-mid of troposphere. Latent heat release from vapor condensation plays positive feedback to the ascending air. It's a key for the heavy rainfall maintaining and development that a strong pump at 200hPa exists, which interacts with vapor condensation heating.

Abstract:A heavy rainfall in Hunan Province in June 2005 is diagnosed based on NCEP/NCAR reanalysis data and observational data. The results show that the most intensive moisture convergence, the strongest ascending movement and the most instable convection stratification all occur in the rainfall center. The heavy rain region locates at the rising branch of a secondary circulation forced by the convergence of the ageostrophic wet Q-vector. Descending flows prevail at the south and north sides of this convergence center and produce a compensation effect, which is favorable for maintaining the heavy rainfall. Convergence of the ageostrophic wet Q-vector has a forecast significance for the coming 6h rainfall area through producing a secondary circulation and reinforcing the storm. The rainfall occurrs at the warm and wet side of the negative value center of the moist potential vorticity (MPV) at 700 hPa and relative MPV at 850hPa. The warm and wet advection and the strong ascending movement at lower level lead to the compensation of the moist air and the upward transport heat, and strengthen the high-level divergence and low-level convergence, which ultimately reinforce the storm.

Abstract:Based on the reanalysis data (1°×1°, 4-times-a-day’s)of NCEP, the high-density automatic gauge’s rainfall data and the conventional meteorological data, a synoptic and dynamic diagnosis of the continuous rainfall event from June 17 to 21,2005 in Jiangxi Province is made. The results show the event was caused by 9 local meso-β scale cloud clusters and 12 eastward-moving and growing strong convective rain clusters. Low level convergence, upper level divergence and up-ward flows are very important to the intensification and maintain of the meso-β scale convective cloud clusters and rain clusters, therefore they are related well to the intensity of the heavy rain. The jet-cores appear, develop and move eastward continuously in the 850hPa southwest jet stream with the meso-scale cloud cluster and convective rain cluster in the 200km north of the jet-cores.

Abstract:An analysis of the structure features and the heavy rainfall of landing typhoon Maisha during 6—9 Aug. 2005 are performed with the dense observational data, the satellite TBB data and NCEP re-analysis data. The results show that the typhoon maintained extinguish asymmetry structure and had stronger convective clouds in the east and north of the typhoon during its long distance travel in East China. The surface vorticity and divergence fields were asymmetric. The center of surface positive vorticity located mainly in the east of typhoon and moved to northeast part of the typhoon as its northward walking. A strong convergent region extended northward accompanied the surface inverted trough. The 850 hPa winds in east and north of the typhoon were stronger than that in other direction, a strong easterly low-level jet sustained in north of the typhoon. The eastern part of the typhoon was warm and the western was cold, there was strong warm advection in the northeast of the typhoon due to the asymmetry of flow and thermal fields. The development of the 200 hPa upper level jet and the upper level divergence generated in right side of this jet exit region provided good dynamical conditions to the typhoon when it was traveling in East China for the long time and was helpful to maintain its intensity. The ascending motion in 500hPa is directly associated with the area of heavy rain caused by the typhoon.

Abstract:Based on the meteorological data, such as temperature, light and humidity, observed outside and inside the greenhouse in Shouguang vegetable production base, Shandong Province, the influences of outside meteorological conditions on the conditions inside greenhouse is analyzed. Based on this analysis, some guidelines are put forward on using the weather forecast in the greenhouse vagetable production.

Abstract:National Basic Automatic Weather Station (AWS) data of A-format is a kind of integrated observation data, which includes kinds of elements and generous information. For realizing the effective quality control, more comprehensive quality control method is studied. According to software engineering theory, application software is developed with modularization design method. It is of great importance to the quality of National Basic Automatic Weather Station (AWS) data.

Abstract:With the NOAA meteorological satellite data and the soil moisture data from surface observation station, the methods of drought disaster monitoring in Anhui Province are introduced. A service system of drought disaster monitoring and warning and forecasting is developed, and a detailed introduction on its structure and function is given.