Meteor radar observations of polar mesospheric summer echoes over Svalbard

A 31 MHz meteor radar located in Svalbard was used to observe polar mesospheric echoes (PMSEs) during summer 2020. Data from 19 July were selected for detailed analysis, with a focus on extracting additional information to characterize the atmosphere in the PMSE region. The use of an all-sky meteor...

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Bibliographic Details
Published in:Atmospheric Measurement Techniques
Main Authors: J. P. Younger, I. M. Reid, C. L. Adami, C. M. Hall, M. Tsutsumi
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2021
Subjects:
Online Access:https://doi.org/10.5194/amt-14-5015-2021
https://doaj.org/article/78a9d5e518114e649de841fd7c105a9b
Description
Summary:A 31 MHz meteor radar located in Svalbard was used to observe polar mesospheric echoes (PMSEs) during summer 2020. Data from 19 July were selected for detailed analysis, with a focus on extracting additional information to characterize the atmosphere in the PMSE region. The use of an all-sky meteor radar adds an additional use to data collected for meteor observations and enables the detection of PMSE layers across a wide field of view. Comparison with data from a 53.5 MHz narrow-beam mesosphere–stratosphere–troposphere (MST) radar shows good agreement in the morphology of the layer as detected between the two systems. Doppler spectra of PMSE layers reveal fine structure, including regions of enhanced return that move across the radar's field of view. Examination of the relationship between range and Doppler shift of off-zenith portions of the layer enables the estimation of wind speeds with high temporal resolution during PMSE conditions. Trials demonstrate good agreement between wind speeds obtained from PMSE Doppler spectra and those calculated from specular meteor trail radial velocities. Combined with the antenna polar diagram of the radar, this same relationship was used to infer the aspect sensitivity of observed PMSE backscatter, yielding a mean backscatter angular width of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">6.8</mn><mo>±</mo><mn mathvariant="normal">3.3</mn><msup><mi/><mo>∘</mo></msup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="48pt" height="11pt" class="svg-formula" dspmath="mathimg" md5hash="5fae8b3bd973bef0bb575719d6195061"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-14-5015-2021-ie00001.svg" width="48pt" height="11pt" src="amt-14-5015-2021-ie00001.png"/></svg:svg> . A comparison of underdense meteor radar echo decay times during and ...