Regional Cloud Analysis Based On New Generation Geostationary Meteorological Satellite Data

In the evolutions of the weather system,Clouds should be given a great deal of attention as main performers.With the influence of the different monsoon the changes of the tropical cyclones and the subtropical anticyclone,the seasonal variations,and geographical distribution of the clouds vary greatly.In the face of complex geographical conditions as well as the climate environment,the comprehensive deployment and efficient use of highly sophisticated weapons such as missiles,stealth fighter aircraft J20 and carrier-based aircraft J15,in addition,the overall planning,deployment and implementation of strategic,operational and tactical operations,Clouds are such an important environmental element that they can't be ignore.Particularly,low clouds are one of the key factors that influence the precision of missiles when it hits the target.There is no doubt that many countries glare at The South China Sea region with a covetous look.The South China Sea region play an important role as a strategic position,and the climate in this region is complex.In the South China Sea and its surrounding area,the conventional observational data are scarce.Even there are some stations with conventional observations on the coastal cities of The South China Sea and the island of Taiwan.What's more,the handful of ships may return a few information about weather which seem unstable.Compared with the satellite data,the spatial resolution and the time resolution of the routine meteorological observation data still have a wide gap.In addition,the error caused by artificial observation cloud at night is larger.In the interest of providing cloud information in the South China Sea when data blockade or lack of data,systemically,it studies the cloud detection algorithm,cloud classification algorithm and related cloud product features of a new generation of geostationary meteorological satellite Himawari-8 in depth.Making use of the high temporal and spatial resolution satellite cloud product data of the Himawari-8 as well as FY-2G,we do synthetic calculation.With the computing result,the paper analyses the target area cloud of the South China Sea region.The main research contents are as follows:(1)Taking full advantage of the Himawari-8 original cloud data,the paper studies the cloud detection algorithm,cloud classification algorithm and convective cloud recognition algorithm systemically.(2)With the use of cloud product data of Himawari-8 and the FY-2G,it figures out the nephograms,the paper picks out a station from the nephograms,then with contrasting to the observation data,the consequence which is analyzed turn out that the synthetic nephogram with the data of Himawari-8 is indicated and reliable.(3)According to the nephograms,the temporal and spatial distribution of clouds and its surrounding areas was analyzed,and the correlation between low clouds and SST(sea surface temperature)was studied in depth.The distribution of total cloud amount in the South China Sea and its surrounding areas has significant seasonal changes,the season with the highest total amount of cloud cover is summer.The results show that:In spring,autumn and winter,there are more high-level clouds in the region near the equator,and in summer they go Mainly along the periphery of the subtropical anticyclone,High-level clouds distribution exist obvious seasonal variation.Especially in the high cloud,the summer is mainly affected by the tropical cyclone and the monsoon,and the cloud cover is much higher than the other seasons.The cloud cover of the middle cloud is mostly in the north and south and is less in the middle,mainly the cloudiness with high value are still concentrated near the equator,and there is a lowvalue centers all year round.The low-level clouds are mainly distributed in the South China Sea,Due to the influence of subtropical anticyclone,the land has a relatively small amount of cloud cover.The spatial distribution of total cloud amount,high,middle and low cloud amount was analyzed according to comparison.The low cloud mainly distributed in the northern part of South China Sea.The high value area of midcloud was over southern China.The high cloud mainly distributed in the southern part of South China Sea.As to the high values of cloud cover area,the distribution of highlevel clouds and generally coincide with the total cloud cover,and the seasonal changes are basically similar,besides the high-level clouds take over the highest percentage of total clouds covered.There is a significant monthly variation of cloud cover in the South China Sea and its surrounding areas.The change of total cloud cover is most similar to that of high cloud cover.From January to April,the low cloud cover played a dominant role in the total cloud cover,while the high cloud in April to October accounted for the major part of the total cloud cover,while the mid-cloud dominated from November to December.The low cloud is greatly affected by the underlying surface,especially influenced by the temperature distribution of the sea surface.It is the areas where the sea surface temperature gradient is high that the amount of low cloud cover is obviously higher.However,the high and medium clouds mainly correspond to the strong convection system and are less affected by the underlying surface.