D region observations by VHF and HF radars during a rocket campaign at Andøya dedicated to investigations of PMWE

Ralph Latteck,Boris Strelnikov,Toralf Renkwitz

doi:10.5194/ars-17-225-2019

Abstract

Abstract. In April 2018 the PMWE1 sounding rocket campaign was conducted at the Andøya Space Center involving coordinated measurements with rockets and ground instruments to measure parameters relevant for testing of the existing theories of polar mesospheric winter echo (PMWE) formation. The Middle Atmosphere Alomar Radar System (MAARSY) was operated to detect PMWE with multiple beam directions to detect favorable launch conditions. A dedicated experiment configuration with five different beam positions was used to point the radar beam along the planned trajectory of the payload. This special radar experiment allowed to obtain basic information about the spatial structure of the PMWE and its dynamical behavior around the flight of the two rockets. PMWE with signal strengths between 10−17 and 10−15 m−1 have been observed by MAARSY during the whole campaign period, starting with a moderate occurrence at the beginning which decreased towards the end of the campaign. Furthermore real common-volume observations by rocket instruments and radar soundings have been carried out at PMWE altitudes on up-leg and down-leg of the rocket flights. The Saura MF radar was operated during both flights probing the mesosphere with a multiple beam scan experiment to derive horizontal winds and electron density profiles. The obtained PMWE characteristics as signal strength and spectral width of the received radar signals as well as estimated horizontal winds and electron densities are presented with particular emphasis to the launch times of the sounding rockets.

Highlights

VHF radar echoes from the mesopause region obtained at polar and middle latitudes during summer time have been used to investigate the behaviour of the mesosphere for more than 30 years
polar mesospheric winter echo (PMWE) with signal strengths between 10−17 and 10−15 m−1 have been observed by Middle Atmosphere Alomar Radar System (MAARSY) during the whole campaign period, starting with a moderate occurrence at the beginning which decreased towards the end of the campaign
An example of a PMWE observed by the Middle Atmosphere Alomar Radar System (MAARSY) in November 2017 is shown in Fig. 1 as height-time-intensity plot of the detected radar volume reflectivity

Summary

Introduction

VHF radar echoes from the mesopause region obtained at polar and middle latitudes during summer time have been used to investigate the behaviour of the mesosphere for more than 30 years. The currently most acceptable explanation of a PMWE formation mechanism supported by measurements with lidar and radar (Kirkwood et al, 2002; Belova et al, 2005; Kero et al, 2008; La Hoz and Havnes, 2008) suggests neutral air turbulence in combination with small charged aerosol particles (probably of meteoric origin) playing a similar role as in the case of PMSE MAARSY is continuously running throughout the year observing the both PMSE and PMWE which are used to study dynamics in the mesosphere/lower thermosphere (MLT) region (e.g., Rapp et al, 2011; Strelnikov et al, 2017) and to support sounding rocket campaigns (e.g., Havnes et al, 2018; Strelnikov et al, 2019).

Long term observations of polar mesosphere winter echoes at Andøya

Overview

MAARSY: experiment configuration and observations

Spectral width analysis of radar data

Results from spectral width analysis of Saura MF radar data

Summary