Characters of polar mesosphere winter echoes at 224 MHz in November 2004

Through researching the polar mesosphere winter echoes (PMWE) of five consecutive days during the solar proton event detected by 224 MHz radar from November 9th to 13th in 2004, we find that the enhancing ionization in D-region can increase the probability of PMWE production, and when intensity of PMWE is greater, the duration is longer and the height range is larger. In addition, the occurrence of PMWE during the days is high vhile the nights is low, because the ionization level of D-region during daytime is higher than night. Moreover, the relation between PMSE and the maximum of cosmic noise absorption (CNA) is analyzed, and we find that the PMSE has a close relation with the increasing electron density in ionosphere D region due to the precipitation of high-energy particle. At the same time, it is found that the polar mesosphere winter echoes and polar mesosphere summer echoes volume reflectivity are different depending on frequency, which may suggest that their mechanism may be different.