Observations On Thermospheric Vector Wind Field During Substorms By An All-Sky FPI

Upper atmospheric temperatures and wind fields are important for space weather forecasts and for the safety of low-orbit aircraft. Research on this region is of great interest for understanding global aerodynamics and solar-terrestrial coupling. A Fabry-Perot interferometer (FPI) is a multiple beam interferometer that makes it possible to obtain information on thermospheric airglow from its interference fringes. In this paper, we introduced the development and the inversion methods of detecting wind field and temperature of upper atmosphere by an all-sky FPI in details.We analyzed the detection principle of FPI, and introduced the all-sky FPI interferometer data processing method in getting the center, radius and line of sight wind of interference fringes. Presents a new retrieval method on calculating the three-dimensional wind field based on multi interference rings. We also introduced the pretreatment of line of sight wind field and did calibration of interference fringes corresponding to the zenith. We calculated the interferogram obtained by computer simulation by using the algorithm we presented, and proved the feasibility of the algorithm.Then, we describe the analysis of six auroral substorm events from17February to21February,2012(630nm), and from12to13November, and10December,2012(557nm). The results were compared with the auroral photos with two sets of all-sky CCD camara at630nm and557nm band, then we discussed the variations in wind field changes with aurora morphology during substorms.We also employed an all-sky Fabry-Perot interferometer (FPI) to observe the two-dimensional horizontal wind field and combined the results with data from ACE sattllite, a fluxgate magnetometer installed at Yellow River Station, and the Super Dual Auroral Radar Network (SuperDARN). The results demonstrate that, there were no obvious southern IMF components, and also in Solar Wind parameters. Despite this, the auroral electrojet index were upgraded significantly during substorms. The magnetometer data in the auroral substorm period and wind variations are orthogonal clear correlation, under the case of "decreasing Bxmag, increasing Bymag and Bzmag ".During auroral substorms, the vector wind field is related closely to variations in the ion drift and geomagnetic field, which were derived from the comparisons during wind field and the ion drift measured by SuperDARN. Moreover, we observed a changing wind field of approximately300m/s in response to variations in the electric and magnetic fields (likely caused by ion drag) and a disturbance of about200m/s that we attribute to the interaction of Joule heating and ion drag. The lag time of ion drag effect of630nm airglow emission layer was slightly longer than that of557nm emission layer, which were15-30and2-10minutes respectively. In addition, a substorm event during weak disturbance period (event6) shows that:there is a long time before this event, the accumulation of the solar wind energy were injected into the ionosphere, which leaded to substorm. In this event, zonal wind vector is dominant,in their violent disturbance.