Remote sensing of mesospheric dust layers using active modulation of PMWE by high-power radiowaves

This paper presents the first study of the modulation of polar mesospheric winter echoes (PMWE) by artificial radiowave heating using computational modeling and experimental observation in different radar frequency bands. The temporal behavior of PMWE response to HF pump heating can be employed to diagnose the charged dust layer associated with Mesospheric Smoke Paricles (MSP). Specifically, the rise and fall time of radar echo strength as well as relaxation and recovery time after heater turn-on and off are distinct parameters that are a function of radar frequency. The variation of PMWE strength with PMWE source region parameters such as electron-neutral collision frequency, photodetachment current, electron temperature enhancement ratio, dust density and radius is considered. The comparison of recent PMWE measurements at 56 MHz and 224 MHz with computational results is discussed and dust parameters in the PMWE generation regime are estimated. Predictions for HF PMWE modification and its connection to the dust charging process by free electrons is investigated. The possibility for remote sensing of dust and plasma parameters in artificially modified PMWE regions using simultaneous measurements in multiple frequency bands are discussed. D R A F T October 1, 2016, 11:40am D R A F T MAHMOUDIAN ET AL.,: ACTIVE MODULATION OF PMWE X 3