2004, 30(1):3-7. DOI: 10.7519/j.issn.1000-0526.2004.1.001
Abstract:With the development of super computer and the advances of new probing techniques, such as radar, satellite observations, GPS, and etc., it makes the non hydrostatic meso scale model operationally possible.Therefore, most of the meteorological centers are devoted to develop the non hydrostatic model systems in order to replace the current hydrostatic model system, and some significant progress has been made, which is exemplified by the newly developed unified model system at the United Kingdom Meteorological Office. Based on these, the current status and its outlook of the non hydrostatic meso scale model are described . And some aspects focus on various design issues are also discussed.
2004, 30(1):8-12. DOI: 10.7519/j.issn.1000-0526.2004.1.002
Abstract:Based on TOMS ozone data from 1978.11 to 1993.4 and surface data of China, relationships between ozone variation over polar and Tibetan Plateau areas and the variation of precipitation and temperature in China are investigated. Results indicate that the variation of precipitation and temperature in China is closely related to the ozone variation over polar areas in spring and Tibetan Plateau in winter, so ozone variation can be used to prognosticate the precipitation and temperature in some parts of China.
2004, 30(1):13-15. DOI: 10.7519/j.issn.1000-0526.2004.1.003
Abstract:The landslide is the most serious geological disaster and the most serious natural disaster and next to the disasters of flood and drought in Jiangxi province. Rainfall and human activities are of the very important triggering factors of the landslide relating to geological condition. The data of landslide and rainfall from 1970 are analyzed and the relation between the landslide and rainfall are studied. The result shows the occurrence of landslide is closely related with rainfall in 3 days, and the total rainfall in a process and its duration. A mathematic statistical model in which daily combined rainfall is used to predict the occurrence of landslide is developed and the applicational tests indicated good effect of the application of the model to 3 serious landslide events in 2002 in Jiangxi province.
2004, 30(1):16-21. DOI: 10.7519/j.issn.1000-0526.2004.1.004
Abstract:By using physical quantity fields of T213 and objective diagnose analysis system of Beijing University, a synoptic and dynamic analysis of the first heavy rain over Huaihe Valley during Meiyu period in 2003 is made. The low level shear system, which is composed of the southward downdraft branch of upper level northern jet and the ascend branch of low level jet, is the main synoptic system. The vapors mainly come from the Bengal Bay and the South China Sea, but the role of vapors convey from East China Waters shouldn't be ignored. The heavy rain region appears below the positive vorticity center of the mid low level convergence and upper level divergence and near the west side of negative vorticity. And the high value center of the wet potential vorticity coincides with the heavy rain region is instructive to the forecast of heavy rain. The trigger role of frontogenesis by the low level convergence region, vapor supplement and low-level advection is the main reason of the maintenance of heavy rain.
2004, 30(1):22-27. DOI: 10.7519/j.issn.1000-0526.2004.1.005
Abstract:A heavy rain process over the Huaihe Valley during 29 June-2 July 2003 was studied to analyze the thermodynamic and dynamic features of Meiyu front. The following are some conclusions: (1) The event happened under "double blocking" Meiyu synoptic situation, dynamic and thermodynamic structure of the Meiyu front continuously changed. Generally, Meiyu front shows a feature of baroclinicity, but sometimes the front is almost vertical with an apparent quasi barotropy feature. (2)The moisture and energy provided by the convergence and upward motion of the strong southwestern warm and moist air current were responsible for the strengthening and maintaining of the Meiyu front. The heavy precipitation area was located in the strong gradient region north to the maximum of moisture flux.
2004, 30(1):28-32. DOI: 10.7519/j.issn.1000-0526.2004.1.006
Abstract:A heavy rainfall during 24-25 June 2003 in the Jiangnan area is simulated by the fine meshed WRF mesoscale numerical model developed by NACR, NCEP, FSL/NOAA et al.. Analysis of the output data indicate that WRF model successfully reveals the circulation's evolution and the distribution of rainfall belt. The convergence field non homogeneously located on the low level shear line and the vorticity (positive at middle low level and negative at upper level) contribute to the strong ascending motion. The air is rather unstable near the moisture frontal zone. Results also show the positive centers of local helicity along the shear line match the heavy rainfall centers quite well.
2004, 30(1):33-37. DOI: 10.7519/j.issn.1000-0526.2004.1.007
Abstract:A synoptic dynamic diagnosis of the heavy rain event in the Huaihe River valley from 4 to 7 July 2003 is carried out with the theory of isentropic potential vorticity (IPV). The results show that the westerly jet on the isentropic surface transported the high potential vorticity to the lower reaches, while the strong NW flow traversing the isobars became a strong sinking flow and transported the high IPV southward from higher layers and higher latitudes. This process kept a high IPV above the rain area and thus counted for the persistency of the heavy rain band. High IPV area is closely associated with heavy rain and thus can be a significant predictor.
2004, 30(1):38-40. DOI: 10.7519/j.issn.1000-0526.2004.1.008
Abstract:A series of tornado events occurred during 8 July 2003 in Anhui province is analyzed briefly with the new generation weather radar data. From the night of 8 to the early morning of 9 July 2003, associated with a mesoscale squall line which embodied within a large precipitation area, a series of four smallscale vortex signatures appear at the leading edge of the squall line. One of the microscale vortex lasted two and a half hour, produced tornadoes in Lujiang county and Wuwei county, consecutively. The tornado in Wuwei county attained F2-F3 and caused severe life loss and poverty damage. Analysis shows that this tornado is a non supercell tornado, which presents little signature on reflectivity maps but clear micro vortex signature on radial velocity maps could be seen, indicating that the new generation weather radar, with its ability to measure the radial velocity, greatly enhanced weather radar's capability to detect the tornadoes.
2004, 30(1):41-45. DOI: 10.7519/j.issn.1000-0526.2004.1.009
Abstract:Based on visibility and fog data from 1980 to 2000, the characters of fog and visibility, and the evolvement rules are studied. The result shows that visibility in summer is better than that in Winter. This may be caused by different prevailing wind, transportation of pollutants, and different weather condition between winter and summer. There is a downtrend of Xiamen's visibility. Days of light fog are increasing. Visibility in Xiamen is much better than that in Beijing where is serious pollution. Xiamen's visibility has distinctly daily variations, it is related with sea land breeze in summer.
2004, 30(1):46-49. DOI: 10.7519/j.issn.1000-0526.2004.1.010
Abstract:By the use of routine meteorological data, cloud images and radar echo, the mesoscale shear of 500hPa altitude and the forming and development conditions of convective precipitation are analyzed. It suggests that the allocation of mesoscale shear of 500hPa altitude and positive environment filed results in the development of convective cloud cluster and that different environment wind shear allocation is closely related to the developing, strengthening, moving and merging convective cell.
2004, 30(1):50-53. DOI: 10.7519/j.issn.1000-0526.2004.01.011
Abstract:Through the comparison between the remote sensing data by automatic station model Ⅱ and routine observation in Fujing Province from 2000 to 2001,the difference between the remote sensing data and historical data, and the evaluation are derived. The conclusion is in favor of the quality of new type observational data and it indicates that the feasibility, reliability and the active role of the technical method of the quality evaluation could be taken as a whole.

