Analysis Of Night Airglow Observations Of Ionosphere Plasma Bubbles Over Hainan Region

The plasma irrgularrities, which are called plasma bubbles, are one of the primary cause of ionospheric scintillations in the low-latitudes ionosphere. It is very useful to study the ionospheric plasma bubbles. A wider range of plasma bubbles could be observed through airglow imaging, and their structure, variation and motions could be derived by those photos. There are many research results on this area at abroad, but rarely at home. In this thesis, the plasma bubbles over Hainan region have been observed and researched by using airglow imager for a long time. The main work is given as follows:(1) All of the lastest work results were almost surveyed not only from optical detecting but also by radio means. Some technologies of detecting plasma bubbles with airglow imager were learnt. After adjusting the paraments of the airglow imager at Hainan Station, the original airglow photos include the plasma bubbles are obtained.(2) By using image processing techniques such as image enhancement, azimuth correction, image projection and so on, the original airglow photos were transformed plasma bubbles pictures, which are clear and azimuth corrected. According to the characteristics of plasma bubbles, the further processing methods were proposed.(3) The characteristies of plasma bubbles over Hainan region are concluded by analyzing these processed images. It is the shape of the North-South strip and after a period time it appears bifurcation. It always tilts towards the west. The dimensions of east-west direction of the bubbles are between tens to hundreds kilometers. It drifts eastward. West wall is more stable than east wall while drifting. A typical drift velocity is 50~150 m/s. By the statistics from September 2013 to May 2014, the bubbles almost appears in 1~2 hours after sunset and lasts for 1~4 hours.(4) By comparing the optical data and GPS data, it has been shown that TEC(total electron content) would decrease and S4(amplitude scintillation index) would raise when plasma bubbles appeared. The plasma bubbles is an important condition of scintillation has been illustrated by statistical analysis of S4 and optical data.