Features of the electric field HF wave of the Sun-synchronous orbit in the solar minimum year

Using the electric field High Frequency (HF) waves recorded by the Instrument Champ Electrique (ICE) onboard the DEMETER spacecraft, the spatial features of the waves from 10 kHz to 3. 33 MHz are studied. During the quiet time, the higher the HF wave, the bigger the power spectrum intensity when the frequency lies between 2. 08 MHz and 3. 33 MHz. At the same time, the power spectrum intensity is almost uniform in different longitudes and latitudes. The difference of the power spectrum intensity between different longitudes and latitudes in the dayside is less than that of the nightside. The seasonal changes of the HF power spectrum intensity mainly show that there are peaks at the dayside low latitudes in the frequency bands of 1. 25 MHz and 1. 66 MHz. During the quiet time, the discrepancy of the power spectrum intensity between different longitudes and latitudes obviously occurs at the frequency bands of 0. 42 MHz and 1. 66 MHz especially at high latitudes of the northern hemisphere in the dayside. During the geomagnetic activity, the HF response mainly appears at the low frequency band especially in the high latitude area. At the equator and low latitudes (latitude is between ±40°) , the geomagnetic response of the HF is weak while that of the nightside in the magnetotail direction becomes strong especially during the storms. Both in the northern and southern high latitudes during the storms on the nightside, the biggest power spectrum intensity is ten times as large as those of the quiet. The biggest power spectrum intensity on the dayside of the high latitude of the southern hemisphere during the substorm and the period of the high latitude magnetic perturbation is ten times as large as that of the quiet. Considering that the perturbation coming from the space has an effect on the high latitude area during the substorm and the period of the high latitude magnetic perturbation, the enhancement of the HF power spectrum intensity may originate from the spatial process. In view of that the data used in this paper occur in the solar minimum year and most of the storms are very weak with the strongest storm belonging to the moderate storm, the enhancements of the HF power spectrum intensity during the strong, severe even the great storms may be more obvious. If there is anomalous accretion in local area during quiet time especially when there is no storm, the abnormal phenomena will be the ionospheric seismo-response mainly brought by the factors of the internal earth.