Study On The Operation And Application Of CINRAD/SA Radar In Shijiazhuang

In order to forecast the severe convection weather happened in the south-central area of Hebei province rightly, and grasp the performance characteristic of CINRAD/SA radar, radar operation status of CINRAD/SA in Shijiazhuang for 1 year were statistically analyzed. Utilizing the products of the Doppler radar in Shijiazhuang, such as Base Reflectivity, Base Velocity, Storm Tracking Information, Hail Index, Vertically Integrated Liquid, Mesocyclone etc., combining with high altitude, ground weather condition, and using the wind direction and wind velocity, divergence and vertical velocity that calculate through VAD and EVAD method, the environment condition and radar echo evolvement characteristics of severe convection weather in the south-central area of Hebei province were analyzed in this article. The orographic effect of Taihang Mountain on the severe convection weather evolvement was studied. The data file and the displaying method of the CINRAD's products in MICAPS were studied .The results show as the follows:(1)The operation status of CINRAD/SA has close relation with communication network, computer, and environment temperature of radar. The environment of locale has obvious influence on the working status of radar. There are more faults in transmitter and antenna control system, and they are key parts of routine maintenance. Administration of network should be intensive, and high-performance computer should be used. Routine maintenance and optimum environment of equipment are very important as well.(2)There are distinct differences between hail and short time rainstorm in the south-central area of Hebei province. Most of the wind direction of the short time rainstorm is eastern or southern and most of wind direction of the hail is western or northern in the middle level of the echo. Position of the wind shear of hail is higher than the short time rainstorm. The average wind speed of hail is higher than the short time rainstorm. There is a sharp increase of wind speed at the height of 3-6km,and reaches up to the peak at the height of 6-9km.Raising and sinking movement are more distinct in the hail than the short time rainstorm.(3)Products such as Storm Tracking Information, Hail Index, Vertically Integrated Liquid, and Mesocyclone etc., are more proper for hail recognition. The "belt" and "hook" shape of radar echo in the Base Reflectivity and Base Velocity products are the important characteristics of hail. The characteristics appear earlier in the Base Velocity products than the Base Reflectivity. There is a distinct raising movement in the environment air before the hail happened and a sinking movement after the hail happened. In the divergence vertical profile map, convergence at the low level and divergence at the upper level corresponding to the raising movement and divergence at the low level and convergence at the upper level corresponding to the sinking movement.(4)The heavy rain in south-central of Hebei province often shows as a vortex shape echo embedding with convection cell cluster or belt in the large scale stratiformcloud in the Base reflectivity products. In the Base velocity products, there are strong southeast or east wind and "positive "and "negative" velocity pair. With the anticlockwise movement of echo, the southeast or east wind become weaker gradually, the northeast wind become stronger in lower-middle level, and the west wind become stronger in the upper. With the clockwise movement, the echo disappeared gradually. There is warm advection in the lower and cold advection in the upper in vertical velocity profile map.(5)Topography shear line appears along the direction line of 30-120° . With development of convection weather, zero velocity line has a change in position, shape, convergence or divergence of the airflow in two sides. This kind of change usually has some connection with the evolvement of sever convection weather. The sever convection weather appear earlier in mountain area. The movement velocity of echo becomes faster in the plain because of the down-slope effect. The intensity, range, height, or movement velocity often increase when the echo arrive at the up area of water. The mountain terrain has precipitation enhancement effect under some circumstances.(6)The data file and the displaying method of the CINRAD's product in MICAPS are studied. Through converting the radar echo data in polar coordinate into the data in grid coordinate, changing the head of BMP picture file, calculating the zoom coefficient in different coordinate, and changing the color map file, the 13th data file of MICAPS is obtained.