Papers by Author: Shi Gong Wang

Abstract: Extreme temperature events in China have been simulated by using the Beijing Climate Center Climate System Model (BCC_CSM1.0). Daily observed temperature data for 1961-2006 at stations in China are used for comparison. The result shows that the value of simulation is consistent with the observation. But the consequence has a lower value especially Qinghai-Tibet Plateau; there is a good simulation for BCC_CSM1.0 for temperature and extreme indices over China in a certain range of error. Trends of indices of extreme temperature are increased.

Abstract: A serial of numerical experiments were conducted with four representative sand and dust emission schemes using an integrated numerical simulation and forecast system of dust storms. The comparison between the simulation results and the observation data shows that the vertical dust flux and the dust concentration of the scheme developed by Marticorena and Bergametti is the biggest, while those of the scheme developed by Lu and Shao is the smallest. The simulation effect of the dust emission scheme developed by Shao is similar to the observation, so the dust model system of Shao is preferably used to predict the dust events in China.

Abstract: With the large-scale and rapid development of wind power in China, the accuracy of wind power prediction is asked for higher. So how to improve the accuracy of numerical weather prediction models which forecast wind has become an important and critical issue. That the accuracy of numerical prediction models as well as the bias of background data is main cause why generate simulated error. This paper attempted to employ the advanced WRF model to simulate the low-level wind in arid region of northwest China, and then evaluated the impact size that using FNL and GFS background data. The results show that using FNL and GFS data simulated wind is very close. It is found that simulation results driven by the FNL assimilated data are worse sometimes. Consequently, we can conclude that FNL assimilated data as well as GFS forecast data are close and the assimilation of FNL data is still need to improvement in northwest China.

Abstract: There are existing objective, quantitative blocking indices that could be classified into five types: the departure method, the Tibaldi and Molteni（TM） method, the dynamical index(PV-θindex), the dynamical potential vorticity (PV) based index, and the circumfluent type method. Persistent blocking highs can be associated with destructive weather including low temperatures, snowfall, and anomalous freezing from January 1st to February 2nd 2008 in China. Using the daily reanalysis data provided by NCEP/NCAR, the merits and flaws of these five objective methods are studied individually, including the intensity、size and frequency of block. Generally speaking, each method has both advantages and clearly identifiable limitations because of the mathematical formulation for each objective blocking index. Based on the merits and flaws of these blocking indices summarized in this study, investigators and operational meteorologists could apply these blocking indices better if they can select an index compatible with their study objectives, or improve upon and innovate a new method.

Abstract: By using .NET platform and open source Sharpmap technology, a short-range and nowcasting operation system was established for Qinghai. Many kinds of data were integrated in this system, which get from air sounding, satellite, T213 numerical predicting products, doppler radar, lightning position system and automatic weather stations. The system with the functions of ensemble prediction and data retrieval and display, can meet the demand of short-range and nowcasting weather forecast, enhance efficiency of forecaster and provide a support for disaster prevention and mitigation in Qinghai.

Abstract: In order to understand the influence mechanism of dust events on PM10 pollution, the characteristics of atmospheric boundary-layer structure and turbulent flux transport during different kinds of dust events in Lanzhou and their relation with PM10 pollution were analyzed by using the data of PM10 concentration, gradient measurements of meteorological tower and turbulent flux measurements observed at SACOL. As dust events break out, the strong inversion in the boundary layer breaks and a mixing layer develops quickly. With the rise of wind speed, PM10 concentration increases sharply. If there is obvious dust transport from upstream regions, the peak of PM10 concentration can lag behind the peak of wind speed. The vertical transport of momentum flux is very strong. The turbulent momentum downward transport, especially the downward momentum flux of meridional velocity, is the main factor which causes the dust blowing and the heavy PM10 pollution during dust events.