Observation and Study of the Aspect Sensitivity and Echo Mechanism Based on the Wuhan MST Radar

摘要

The observations of the Wuhan mesosphere, stratosphere, and troposphere radar with different tilted angles and observational modes are used to study the aspect sensitivity of the radar echoes and discuss the echo mechanism in the lower thermosphere, mesosphere, lower stratosphere, and troposphere. This letter indicates that: 1) the variation of radar echoes with different tilted angles is more obvious in the troposphere than that in the lower thermosphere, mesosphere, and lower stratosphere; 2) the values of the aspect sensitivity of radar echoes in the tropopause region and the mesopause region are smaller than that in the other region, which shows the difference of the echo mechanism; 3) the radar echo mechanism has the obvious spatial direction difference (S-N and E-W) in the mesosphere and lower stratosphere. Meanwhile, in the lower thermosphere, the sudden probability of radar enhanced echoes is larger, which may be related to the electronic thermal radiation, the scattering of the electron group, meteor trails, or the breaking of the gravity waves; and 4) in the troposphere and the lower stratosphere, the values of the aspect sensitivity increase with the increase of the tilted angles at all most height regions. However, the variations of the values of the aspect sensitivity are not monotonic in the lower thermosphere and mesosphere, which is much different from that in the troposphere and the lower stratosphere.