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The Atmospheric Physical Quantity and Radar Echo Characteristic of A Strong Convective Weather
YANG Qiang-Gong, BANG Jiu-Hui, LIU Wan-Wan
J4    2010, 28 (3): 322-326.  
Abstract1098)      PDF(pc) (1108KB)(1380)       Save

Based on the conventional weather data and the Doppler radar data,a strong convective weather process occurred on July 3,
2007 in Chengde of Hebei Province was analyzed. Results show that the change of atmospheric unstable index and the level and vertical
distribution of θse can reflect the atmospheric stratification condition and the unstable energy accumulation. The temperature advection
and the vertical distribution of helicity can demonstrate the atmospheric thermal and dynamic characteristics before the strong convection
weather occurrence. The divergence and vertical velocity changing with time and height triggered the strong convection weather. The
configuration of high and low level wind field and the air vent index can judge the size of vertical wind shear. The Doppler radar basic
reflection factor played a key role in the pre - alarm of a strong convection weather.

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Analysis of Doppler Radar Characteristic of Short-time Strong Precipitation  in Chengde of Hebei Province
BANG Jiu-Hui, YI Yong-Li, TUN Xian-Chun, YANG Qiang-Gong
J4    2010, 28 (2): 184-189.  
Abstract1663)            Save
Based on the radar data of 39 short-time strong precipitation weather events and the routine observation data of Chengde meteorological station from July 2007 to October 2008, the radar data such as reflectivity factor, radial velocity, VIL , echo tops etc before the beginning and going periods of the strong precipitation were analyzed. The conclusion is that the strong monomer storm or the belt-shaped echo and the laminated mix echo combined by the multi-monomer storm resulted in the short-time strong precipitation in Chengde. The short-time strong precipitation echo could be divided into four types, including echo developing, the polymerization and enhancement, local convergence and the rainstorm pattern. The basic characteristics of radial velocity is that the inflow jet streams or dead wind areas existed in the mid-low layers. The inflow jet streams make the mesoscale convergence in the mid-low layers, and the dead wind areas make the meso-and small scale convergence, which promoted the precipitation echo gathering and developing and resulted in short-time strong precipitation occurrence.
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Prediction and Ana lysis ofWea ther Cond ition s on Pota to Late Blight in Chengde of Hebe i Prov ince
BANG Jiu-Hui, GUO Li-Xia, MA Xiu-Ling, YANG Qiang-Gong, MAO Pei-Zhu
J4    2009, 27 (1): 57-60.  
Abstract1579)      PDF(pc) (235KB)(1586)       Save

The relation between the area of potato late blight and weather conditions in Chengde city during 1990 - 2008 was analyzed.It shows that the biological factor p lays a role under suitable weather conditions in the occurrence of potato late blight. Weather conditions such as temperature, p recip itation, relative humidity, sunshine hours are decisive factors for p revalence of potato late blight. The app rop riate temperature, rainy or foggy weather are most conducive to late blight occurrence and p revalence. Using the affected rate as a criteria to classifymeteorological levels for potato late blight, we selected the p recedingmeteorological elementswhich related well to potato late blight as a p rediction factor, then establish the meteorological forecastingmodel using integrated clusteringmethod. Test results showed that the model can imp rove decision - makingmeteorological service level and win time to control the sp read of potato late blight.

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Ana lysis of a Loca l Snow Storm in Spr ing of 2007 in North Ch ina
MA Xiu-Ling, BANG Jiu-Hui, YANG Lei-Bin, WANG  Hong, YANG Qiang-Gong, LIU Ba-Hua
J4    2008, 26 (1): 64-68.  
Abstract2042)      PDF(pc) (871KB)(3800)       Save

Based on the conventional data, satellite cloud images and Dopp ler Radar data, the snow storm weather occurred in sp ring of
2007 in Chengde was analyzed from the large - scale background, water vapor and dynamic conditions. The results indicate that the
block from the eastern p ressure ridge leads to themerger and intensification of the north and the south low - p ressure systems, andmov2
ing slowly of the low - p ressure system results in this storm event. The convergence in the lower level and the foundation of low level jet
made large - scale water vapor convergence and continualwater vapor transmission, and the deep - thick atmosphere wet layer p rovides
a favourable surrounding condition and the divergence, vertical velocity and k - helicity fields are dynamic conditions for this heavy rain.

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