Research On Chinese Mesoscale Convective Cloud Cluster Characteristic And The Influence On The Route

Mesoscale convective cloud cluster is often accompanied with bad weather phenomenon, so monitoring effectively of identifying and tracing has great practical significance. In this paper, based on recognition criteria of mesoscale convective cloud cluster,studies of mesoscale convective cloud cluster automatic recognition and tracking with the technology of digital image processing and fuzzy pattern recognition. The SUSAN edge detection is used to extract boundary of cloud cluster, and contructing the tracking-template via integrating brightness temperature histogram and multiple feature construction of cloud, to make the cloud tracking come true.Based on the effectively recognizing and tracking of mesoscale convective cloud cluster gathering statistics and analyzing mesoscale convective cloud cluster which appeared in China and its surroundings.According to the results of statistical analysis, clouds has certain regularity in the aspect of overall distribution variation, monthly variation, diurnal variation and attributive character of cloud:(1) overall distribution variation, showing the characteristics of that distribution from south to the north, banding with zonal and distribution with lots of active region. What’s more,the distribution of mesoscale convective cloud cluster has great relation with topography, land and sea in our country. (2) monthly variation, the mesoscale convective cloud showing obvious characteristics of North to South movement. High active period in June to August, during this period,cloud cluster mainly affect most regions of Chinese central and southern.However,affection of cloud in northern of China is smaller during this period. In winter and early spring season, clouds have opposite trend compared to high active period, which shows that mesoscale convective cloud cluster has very obvious seasonal variation. (3) diurnal variation, the appearance time of cloud exhibits two obvious Peak District, the one is from 3 to 9 o’clock in the morning, the other is from 15 to 24 o’clock in the afternoon, indicating that activity time of cloud cluster has obvious regularity. (4) attributive character of cloud, according to comprehensively analyze the three characteristics and high active period of cloud,it is found that the mesoscale convective cloud clusters with more active feature, then with more round rate, lower average brightness temperature of cloud area and area of cloud cover is relatively smaller. In addition, the characteristics of mesoscale convective cloud cluster shows opposite attributive character during inactive period.With the improvement of wind rose map, bring forward radial direction rose to describe the cloud moving speed and direction. Within the region of north latitude 18 degrees to 27 degrees, east longitude 100 degrees to 122 degrees, compiling the statistics of the mobility features of mesoscale convective cloud cluster, and analyzing the results found that the basic direction of movement is from west moved to the East and northeast direction is mobile side throughout the year. However, during the high active period of June to August, the direction of movement of the clouds was to the direction of westward and southwest.Moreover, the average speed of clouds at the lowest level in the annual average mobile speed during this period. Finally, construct the evaluation model to evaluate the influence on route resulting from the mesoscale convective cloud clusters. Calculating and analyzing the evaluation model, it can determine the time of clouds impacting the route of flight,which is the initial time, duration and finish time. In addition, calculate the safety margin of route to represent the availability and security of route characterization during the period of cloud affecting the route. At the same time, based on the above analysis and calculation, the paper carrys out path diversion programs to determine the initial diversion points, turning points and intermediate diverted back into the aircraft turning point,in order to realize about flying on the route under the influence of mesoscale convective cluster.