Study On The Thermospheric Dynamic Model

We have developed a thermospheric dynamic model (TDM) to study theresponse of the thermospheric density, temperature and wind induced by solar activityand geomagnetic disturbance. The model at present can simulate the thermosphericcharacter for the solar and geomagnetic variations. We can simulate the steady wind atdifferent solar activity and geomagnetic disturbance. We calculated the isoline plot ofthe density and temperature at appointed altitude, the vertical section of the density,temperature and wind at appointed longitude and latitude, and so on. The model runssteadily and the results are consistent with HWM93 (Horizontal Neutral Wind Model1993). The model can simulate the variation of the thermospheric temperature, densityand meridional circumfluence induced by the pole heat in the geomagnetic storm. Themodel result is interesting and significant.We simulated the steady wind (at 120km and 300km) and the meridionalcircumfluence at equinox and solstice. The result showed that the meridionalcircumfluence flow from the high latitude area to equator and shows doublecircumfluence character. Especially, at the summer, the meridional circumfluenceflow from 20°N to high latitude area and low latitude area, and flow from the highlatitude area of the south hemisphere to the low latitude area, then these twocircumfluence converge at 20°S. This character is significant to study ionosphere.We qualitatively simulated the thermospheric response for the geomagneticstorm. We give a coefficient of the polar heat to simulate the variation of the wind, thetemperature and the density during geomagnetic storm at spring and summer.