Geomagnetic Responses To Solar Wind Disturbances And Integration Of Space Environment Application Models

This thesis describes a study about the effect of solar wind disturbances on auroral electrojet and ring current indices, the correlation between auroral electrojet bursts and magnetospheric substorms, and a framework of forecast model computing to meet the demand of space environment forecasting operation.First, we investigate the influence of solar wind dynamic pressure changes on the westward auroral electrojet index AL, the eastward auroral electrojet index AU and the ring current index SYM-H using WIND satellite data. It is found that the geomagnetic response to a solar wind pressure pulse is not only related to the strength and duration of the solar wind pressure pulse, but also depends on the energy storage state of the magnetosphere. An increase or decrease in the solar wind dynamic pressure may result in changes of AL, AU and SYM-H synchronously or with time delay. Moreover, the direction and response time of the changes may vary with the properties of the solar wind.Second, we use LANL satellite data and ground magnetic field data to study the relationship between auroral electrojet bursts and substorms. By analyzing the correlation between auroral electrojet bursts and substorms, we divide the auroral electrojet bursts into three categories. In the first category of events, eastward and westward electrojets burst and disappear simultaneously. This kind of auroral electrojet bursts is certainly accompanied by injection of synchronous orbit energetic particles and Pi2magnetic pulsations, which are typical signatures of a substorm. In the second category of events, westward electrojet burst but eastward electrojet remain unchanged, also accompanied by above signatures of a substorm process. The last category of event is characterized by burst of eastward electrojet and unchanged westward electrojet. While some of these events are accompanied by substorms, some are not. These results are important to study and monitor substorms using auroral electrojet indices.Finally, we propose a reasonable and efficient model computing framework on component-based architecture, and some geomagnetic activity related models covering five space regions in solar-terrestrial system are selected for application testing in a cloud computing environment. These models include an intelligent operation forecast model that can forecast the arriving time and strength of solar storm, a kinematic model that can forecast the values of solar wind and magnetic field near the Earth orbit, a magnetospheric state model that can forecast the characteristics of magnetospheric plasma and electromagnetic field, a bow shock/magnetopause configuration model, a solar wind transfer model that can forecast the characteristics of plasma and electromagnetic field in outer magnetosphere, a geomagnetic disturbance forecast model, etc. The framework has a great application value in the space environment forecasting operation in China.