Abstract:Most of damages of landing typhoon result from heavy rainfall, therefore typhoon heavy rainfall is one of the most focused problems in the typhoon research community. During the last 10 years, with the acquisition of much valuable intensive observations in a series of typhoon field experiments, the improvement of the weather monitoring network, the upgrade of atmospheric numerical models and the rapid development of computer powers, many problems in typhoon heavy rainfall research are further studied, such as the interaction between typhoons and mid-latitude weather systems, the interaction between typhoons and topography and underlying surface, the mesoscales of typhoons and the dynamics and so on. The research progresses in recent 10 years are briefly summarized, and some existing issues are discussed.

Abstract:By the use of monthly mean sea surface temperature anomaly (SSTA) data and reanalys-is data from NCAR/NCEP, study of circulation transformation characteristics in the early summer (May or June) in East Asia under the conditions of persistent SSTA is conducted. The results indicate that in the warmer SSTA years, South Asia high and the subtropical high over western Pacific enhanced obviously, in contrast, in colder SSTA years. Subtropical westerly jet of the Northern Hemisphere over Asia-Europe land weakens and shifts northward clearly in warmer years, contemporary, temperature in lower troposphere over East Asia land is higher than or closes to normal, near surface temperature over the Tibetan Plateau is also above normal, while in colder years, temperature mentioned above is lower than or closes to normal, especially for temperature over the Plateau in May. It suggests that persistent SSTA are of great influence to seasonal transitions for East Asia in early summer.

Abstract:Based on the GOES-9 satellite IR images during inundation from 21 June to 22 July 2003, the mesoscale convective systems are investigated over the Huaihe River region. The results revealed: (1) There are total 10 and 24 , the frequency is much larger than the average of an ordinary year. (2) The large number of MCS originated and maturated in Huaihe River region is a main cause of this inundation. (3) The formation time of some of MCSs is different from general MCS. (4) The synoptic environment conditions of the MCS are various.

Abstract:An analysis of the case of aircraft-icing occurred in Taiyuan airport of Shanxi Province 21 December, 2004 is made. It shows that the upper-trough in Hetao area and the high-pressure over the North China composed the background of this event. The equivalent temperature of environment lied between -6℃ and-10℃ was necessary for severe icing when the environment had plenty of moisture. The weak ascend velocity and cold advection are favourable to ice accumulation; WAFS NWP products can effectively describe the dynamics structure of synoptic system. A new icing index can better predict the icing event than the recommended icing-index by ICAO.

Abstract:Based on the rainfall data for the flood season (May to September) from 1961 to 2000 over Tibet, the spatial distribution of precipitation during flood season over Tibet is investigated with the EOF method. The major rain patterns for flood season over Tibet are determined and compared with summer rain belt in the east part of China. It shows that there is close relationship between the rain patterns over Tibet and summer rain belt in the east part of China.

Abstract:Using satellite cloud pictures and data from the intensive and conventional observation, the reason of the heavy rainfall event on 16-17 July 2004 over Shall river area is studied. The results show that the event is directly affected by the formation and evolution of southwest vortex and MCC cloud cluster which locate in the intersection region of the upper-level jet and the low-level jet. In addition, a thought of how to use the mesoscale convergence center, TBB of convective cloud and the radar echo for rainfall rate to predict the mesoscale rain cluster is presented.

Abstract:A heavy rain event on 15 July 2003 in Shaanxi is simulated and diagnosed with MM5 nonhydrostatic model. It shows that there were obvious dynamic-thermodynamic structural features in the developmental phase and mature phase of the heavy rainfall: the strong divergence column and the intensive vorticity column were coupling developed, the extremely intensive ascent motion was intercoupled with saturated air column.

Abstract:An analysis of a heavy rainfall event on 16, July 2004 in Linyi, Shandong is made with radar's VWP product and hourly rainfall data, it shows that the event is characterized with apparent meso-scale features, the vertical structure and maintaining of southwest-moist-jet can be clearly revealed by VWP product, high and low level jet, both with their downward perturbation relate closely with enhancement of rainfall. Extent of rainfall enhancement caused by low level jet's intensification and its downward perturbation is much greater than that of high level jet, and heavy rainfall is mainly induced by low level jet's intensification and perturbation. A jet perturbation index is developed and applied to verify this viewpoint.

Abstract:By using the 714C radar echo data in Shiyan and other weather data, a severe convective weather event in Shiyan on 6, July 2004 is analyzed. The result shows that the severe convective storm occurred under the advantageous large scale weather conditions, with local large CAPE index and strong vertical shear of horizontal wind. Severe hail is caused by multicell severe storm. It has the intensive radar echo, high cloud top, affectation echo on the cloud top caused by radar sidelobe and weak echo region in the lower layer. Hail cloud moves in the right side of the high level wind with right-behind or right-forward propagation. Severe hail is caused by the second propagation, the original echo occurs in the high layer. The cloud top is high and the center of echo locates in the high and middle layer of cloud.

Abstract:Based on the data of GTSI digital radiosonde, NCEP reanalysis data and conventional observation, synoptic analysis of the uncommon long-drawn fog over Huabei plain in the winter of 2004 is made. The result shows that the temperature of layer close to the surface was lowered by negative vorticity advection, cold advection and weak convergence ascending movement below 900hPa, and the temperature of the layer between 900hPa and 500hPa was raised by the positive vorticity advection, warm advection and divergence descending movement, thus the inversion layer is formed in the interface of ascending and descending movement. The height and intensity of the inversion layer could affect on the formation and status of the fog. Radiation cooling during the night and gentle breeze below 950hPa layer are dynamic factors for the formation of fog. Under some synoptic situations, the easterly and southeasterly shoreward wind over Huaibei plain transports the water vapor from northern sea surface to cold land surface layer, and results in the saturation in fog boundary layer.

Abstract:Based on cloud-top brightness temperature data and circulation background, and the physical quantities, Diagnosis of severe convection weather caused by MCS in Mei-yii front over the Yellow Sea-Changjiang River during June 21 to 23, 2002 is made. The results show that the MCS is main system of the heavy rainfall in Mei-yufront over Changjiang River Basin. There is close relationship between the heavy rainfall center and the high occurrence frequency center of convection and deep convection. The frequency of F_M(T_BB≤-32℃)and F_S (T_BB≤52℃) can reflect the characteristics of rainfall well and better than the low value center of T_BB. In addition, the severe heavy rainfall was caused by the interaction among Mei-yu front, lower level shear line and upper level Tibet high.

Abstract:Base on the tropic cyclone data from 1949 to 2003, the spatial-temporal distribution features of influencing and landing tropic cyclone(TC) numbers in Hainan Province, temporal distribution of the first and the last influencing TC to Hainan are analyzed. Furthermore, the relationship between ENSO and the influencing TC to Hainan, and the reasons that no TC influences Hainan in 2004 are investigated. The main results are as follows. (1) Correlation between ENSO and activity of influencing TC to Hainan is significant. (2) Influencing and landing TC to Hainan are getting less and the first influencing TC to Hainan is getting later in warm SSTa event, and vice versa. (3) Correlation between ENSO and the last influencing TC to Hainan is not significant.

Abstract:The eco-environment phenomena, such as desertification, dust weather, soil moisture, soil characteristics, herbage features, etc. have monitored in Qinghai Province. An operational eco-environment monitoring system is developed to ensure for the continuous accumulation of the eco-environment data, and correctly and timely service.

Abstract:In order to realize network constructing for automatic weather station and real-time information query based on webGIS technique, the system for data monitoring and processing is designed and established. The design principle, main functions and the key technology of the system is introduced.

Abstract:The operational monitoring and service systems of drought with remote sensing data have already developed in many provinces. According to the application of the system in Shaanxi Province, its service effects are discussed and some problems are indicated. The methods to solved these problems are also discussed.