scholarly journals Comparative statistical analysis of neutral wind in mid-latitude mesosphere / lower thermosphere based on meteor radar and Fabry — Perot interferome-ter data

2018 ◽  
Vol 4 (2) ◽  
pp. 49-57 ◽  
Author(s):  
Роман Васильев ◽  
Roman Vasilyev ◽  
Максим Артамонов ◽  
Maksim Artamonov ◽  
Евгений Мерзляков ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Geomagnetic Storms ◽  
Lower Thermosphere ◽  
Horizontal Wind ◽  
Neutral Wind ◽  
Eastern Siberia ◽  
Meteor Radar ◽  
Spring Period ◽  
Fabry Perot ◽  
Comparative Statistical Analysis

Studies of the upper atmosphere wind are very important both for understanding the mechanism of transformation of exposure energy into heating, movement and chemical activity of the atmosphere, and similar processes of energy transfer from lower to upper atmospheric layers. Instruments and methods for studying the wind velocity and its variations at different height levels usually complement each other in such studies. We perform a comparative analysis of information about the neutral horizontal wind over Eastern Siberia in the winter-spring period obtained by different methods. We observe some features appearing at different heights during geomagnetic storms and sudden stratospheric warming events. We propose a method for comparative statistical analysis of the neutral wind registered at different sites and show its validity. Using this method, we make a quantitative comparison of winds measured over Eastern Siberia in the winter-spring period. The wind measured by the meteor radar and Fabry-Perot interferometer at 90 km has similar direction and absolute velocity. The wind measured by the Fabry—Perot interferometer at 100 km differs from that estimated by the meteor radar only in direction. The wind measured by the Fabry—Perot interferometer at 250 km has a velocity 2.5 times faster and a direction differing by 30–40° from the wind obtained by the meteor radar.

scholarly journals Comparative statistical analysis of neutral wind in mid-latitude mesosphere / lower thermosphere based on meteor radar and Fabry — Perot interferometer data

2018 ◽  
Vol 4 (2) ◽  
pp. 86-95
Author(s):  
Роман Васильев ◽  
Roman Vasilyev ◽  
Максим Артамонов ◽  
Maksim Artamonov ◽  
Евгений Мерзляков ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Geomagnetic Storms ◽  
Lower Thermosphere ◽  
Horizontal Wind ◽  
Neutral Wind ◽  
Eastern Siberia ◽  
Meteor Radar ◽  
Spring Period ◽  
Fabry Perot ◽  
Comparative Statistical Analysis

Studies of the upper atmosphere wind are very important both for understanding the mechanism of transformation of exposure energy into heating, movement and chemical activity of the atmosphere, and similar processes of energy transfer from lower to upper atmospheric layers. Instruments and methods for studying the wind velocity and its variations at different height levels usually complement each other in such studies. We perform a comparative analysis of information about the neutral horizontal wind over Eastern Siberia in the winter-spring period obtained by different methods. We observe some features appearing at different heights during geomagnetic storms and sudden stratospheric warming events. We propose a method for comparative statistical analysis of the neutral wind registered at different sites and show its validity. Using this method, we make a quantitative comparison of winds measured over Eastern Siberia in the winter-spring period. The wind measured by the meteor radar and Fabry — Perot interferometer at 90 km has similar direction and absolute velocity. The wind measured by the Fabry — Perot interferometer at 100 km differs from that estimated by the meteor radar only in direction. The wind measured by the Fabry — Perot interferometer at 250 km has a velocity 2.5 times faster and a direction differing by 30–40° from the wind obtained by the meteor radar.

scholarly journals The wintertime two-day wave in the polar stratosphere, mesosphere and lower thermosphere

2008 ◽  
Vol 8 (3) ◽  
pp. 749-755 ◽  
Author(s):  
D. J. Sandford ◽  
M. J. Schwartz ◽  
N. J. Mitchell
Keyword(s):  
Lower Thermosphere ◽  
Radar Data ◽  
The Arctic ◽  
Horizontal Wind ◽  
Meteor Radar ◽  
Polar Night ◽  
Zonal Wavenumber ◽  
Mesosphere And Lower Thermosphere ◽  
Polar Stratosphere ◽  
Striking Contrast

Abstract. Recent observations of the polar mesosphere have revealed that waves with periods near two days reach significant amplitudes in both summer and winter. This is in striking contrast to mid-latitude observations where two-day waves maximise in summer only. Here, we use data from a meteor radar at Esrange (68° N, 21° E) in the Arctic and data from the MLS instrument aboard the EOS Aura satellite to investigate the wintertime polar two-day wave in the stratosphere, mesosphere and lower thermosphere. The radar data reveal that mesospheric two-day wave activity measured by horizontal-wind variance has a semi-annual cycle with maxima in winter and summer and equinoctial minima. The MLS data reveal that the summertime wave in the mesosphere is dominated by a westward-travelling zonal wavenumber three wave with significant westward wavenumber four present. It reaches largest amplitudes at mid-latitudes in the southern hemisphere. In the winter polar mesosphere, however, the wave appears to be an eastward-travelling zonal wavenumber two, which is not seen during the summer. At the latitude of Esrange, the eastward-two wave reaches maximum amplitudes near the stratopause and appears related to similar waves previously observed in the polar stratosphere. We conclude that the wintertime polar two-day wave is the mesospheric manifestation of an eastward-propagating, zonal-wavenumber-two wave originating in the stratosphere, maximising at the stratopause and likely to be generated by instabilities in the polar night jet.

scholarly journals The wintertime two-day wave in the Polar Stratosphere, Mesosphere and lower Thermosphere

2007 ◽  
Vol 7 (5) ◽  
pp. 14747-14765
Author(s):  
D. J. Sandford ◽  
M. J. Schwartz ◽  
N. J. Mitchell
Keyword(s):  
Lower Thermosphere ◽  
Radar Data ◽  
The Arctic ◽  
Horizontal Wind ◽  
Meteor Radar ◽  
Polar Night ◽  
Zonal Wavenumber ◽  
Mesosphere And Lower Thermosphere ◽  
Polar Stratosphere ◽  
Striking Contrast

Abstract. Recent observations of the polar mesosphere have revealed that waves with periods near two days reach significant amplitudes in both summer and winter. This is in striking contrast to mid-latitude observations where two-day waves maximise in summer only. Here, we use data from a meteor radar at Esrange (68° N, 21° E) in the Arctic and data from the MLS instrument aboard the EOS Aura satellite to investigate the wintertime polar two-day wave in the stratosphere, mesosphere and lower thermosphere. The radar data reveal that mesospheric two-day wave activity measured by horizontal-wind variance has a semi-annual cycle with maxima in winter and summer and equinoctial minima. The MLS data reveal that the summertime wave in the mesosphere is dominated by a westward-travelling zonal wavenumber three wave with significant westward wavenumber four present. It reaches largest amplitudes at mid-latitudes in the southern hemisphere. In the winter polar mesosphere, however, the wave appears to be an eastward-travelling zonal wavenumber two, which is not seen during the summer. At the latitude of Esrange, the eastward-two wave reaches maximum amplitudes near the stratopause and appears related to similar waves previously observed in the polar stratosphere. We conclude that the wintertime polar two-day wave is the mesospheric manifestation of an eastward-propagating, zonal-wavenumber-two wave originating in the stratosphere, maximising at the stratopause and likely to be generated by instabilities in the polar night jet.

scholarly journals Frequency spectra of horizontal winds in the mesosphere and lower thermosphere region from multistatic specular meteor radar observations during the SIMONe 2018 campaign

2021 ◽  
Author(s):  
Harikrishnan Charuvil Asokan ◽  
Jorge L Chau ◽  
Raffaele Marino ◽  
Juha Vierinen ◽  
Fabio Vargas ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Spread Spectrum ◽  
Lower Thermosphere ◽  
Geographic Area ◽  
Horizontal Wind ◽  
Small Scale ◽  
Meteor Radar ◽  
Frequency Spectra ◽  
Mesosphere And Lower Thermosphere ◽  
Field Correlation

Abstract In recent years, multistatic specular meteor radars (SMRs) have been introduced to study the Mesosphere and Lower Thermosphere (MLT) dynamics with increasing spatial and temporal resolution. In this paper, frequency spectra of MLT horizontal winds are explored through observations from a campaign using the SIMONe (Spread-spectrum Interferometric Multistatic meteor radar Observing Network) approach conducted in northern Germany in 2018 (hereafter SIMONe 2018). The seven-day SIMONe 2018 comprised of fourteen multistatic SMR links and allows to build a substantial database of specular meteor trail events, collecting more than one hundred thousand detections per day within a geographic area of $\sim $ 500 km $\times$ 500 km. We have implemented two methods to obtain the frequency spectra of the horizontal wind components: (1) Mean Wind Estimation (MWE) and (2) Wind field Correlation Function Inversion (WCFI), which utilizes the mean and the covariances of the line of sight velocities, respectively. Monte Carlo simulations of a gravity wave spectral model were implemented to validate and compare both methods. The simulation analyses suggest that the WCFI helps to capture the energy of smaller-scale wind fluctuations than those capture with MWE. Characterization of the spectral slope of the horizontal wind at different MLT altitudes has been conducted on the SIMONe 2018, and it provides evidence that gravity waves with periods smaller than seven hours and greater than two hours dominate with horizontal structures significantly larger than 500 km. These waves might be associated with secondary gravity waves during this observational campaign. In the future, these analyses can be extended to understand the significance of small-scale fluctuations in the MLT, which were not possible with conventional MWE methods.

scholarly journals Stratospheric influence on the mesosphere–lower thermosphere over mid latitudes in winter observed by a Fabry–Perot interferometer

2021 ◽  
Vol 39 (1) ◽  
pp. 267-276
Author(s):  
Olga S. Zorkaltseva ◽  
Roman V. Vasilyev
Keyword(s):  
Zonal Wind ◽  
Emission Intensity ◽  
Lower Thermosphere ◽  
Optical Emission ◽  
Temporal Variations ◽  
Upper Atmosphere ◽  
Eastern Siberia ◽  
Siberian Branch ◽  
Fabry Perot ◽  
Academy Of Sciences

Abstract. In this paper, we study the response of the mesosphere–lower thermosphere (MLT) to sudden stratospheric warmings (SSWs) and the activity of planetary waves (PWs). We observe the 557.7 nm optical emission to retrieve the MLT wind and temperature with the only Fabry–Perot interferometer (FPI) in Russia. The FPI is located at the mid latitudes of eastern Siberia within the Tory Observatory (TOR) at the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences (ISTP SB RAS, 51.8∘ N, 103.1∘ E). Regular interferometer monitoring started in December 2016. Here, we address the temporal variations in the 557.7 nm emission intensity as well as the variations in wind and temperature measured during the 2016–2020 winters. Both SSWs and PWs appear to have equally strong effects in the upper atmosphere. When the 557.7 nm emission decreases due to some influences from below (SSWs or PWs), the temperature increases significantly, as does its variability. The dispersion of zonal wind does not show significant PW- and SSW-correlated variations, but the dominant MLT zonal wind reverses during major SSW events simultaneously with the averaged zonal wind at 60∘ N in the stratosphere.

Validation of multi-static meteor radar analysis using realistic mesospheric dynamics from UA-ICON model: Reliability of gradients and vertical velocities

2021 ◽  
Author(s):  
Harikrishnan Charuvil Asokan ◽  
Jorge Luis Chau ◽  
Juan Federico Conte ◽  
Gerd Baumgarten ◽  
Juha Vierinen ◽  
...  
Keyword(s):  
Spread Spectrum ◽  
General Circulation ◽  
Lower Thermosphere ◽  
Circulation Model ◽  
Horizontal Wind ◽  
Meteor Radar ◽  
Wind Fields ◽  
Network Systems ◽  
Mlt Dynamics ◽  
Static Approach

<p>Specular meteor radars (SMRs) are a major ground-based instrument to study the mesosphere and the lower thermosphere (MLT) dynamics. The recently developed multi-static approach of SMRs allows maximising the number of measurements from different viewing angles, hence enabling the estimation of horizontal wind fields and their second-order statistics (power spectrum, momentum fluxes). We have installed the operational versions of these techniques in Germany, Peru and Argentina, called SIMONe (Spread-spectrum Interferometric Multistatic meteor radar Observing Network) systems. Here, we present a validation study of multi-static meteor radar analysis by using virtual radar systems on the upper-atmosphere extension of the ICOsahedral Non-hydrostatic (UA-ICON) general circulation model with a horizontal grid spacing of 5 km. This particular study is focusing on the estimates of gradients and vertical velocities with these multi-static systems.</p>

Comprehensive comparison of mesospheric wind from Fabry-Perot interferometer and meteor radar at King Sejong Station, Antarctica

2020 ◽  
Author(s):  
Changsup Lee ◽  
Geonhwa Jee ◽  
Qian Wu ◽  
Jeong-Han Kim ◽  
Hosik Kam ◽  
...  
Keyword(s):  
Lower Thermosphere ◽  
Meteor Radar ◽  
Airglow Emission ◽  
Wind Structure ◽  
Fabry Perot ◽  
Airglow Emissions ◽  
Solar Local Time ◽  
Comprehensive Comparison ◽  
Wind Measurements ◽  
Traditional Assumption

<p>Neutral winds in the mesosphere and lower thermosphere (MLT) have been simultaneously observed by Fabry-Perot interferometer (FPI) and meteor radar (MR) at King Sejong Station (KSS), Antarctica from 2017. Because  the airglow emission height sensitively varies with a solar local time and a season, it is not possible to precisely determine what altitude airglow emission occurs from the traditional assumption of fixed airglow layers. Even though a few previous studies suggested representative heights of airglow emission such as OH band and 557.7 nm line, the true height information of these emission are still unknown. In this study, we try to figure out the temporal dependence of the airglow emissions using the KSS FPI and satellite (SABER/MLS) measurements. We also perform a direct comparison between the FPI and the meteor radar wind measurements considering time-varying airglow emission properties based on a correlation analysis. This study presents how the background wind structure can affect wind estimates from the airglow emissions.</p>

scholarly journals Stratospheric influence on MLT over mid-latitudes in winter by Fabry-Perot interferometer data

2020 ◽  
Author(s):  
Olga S. Zorkaltseva ◽  
Roman V. Vasilyev
Keyword(s):  
Zonal Wind ◽  
Lower Thermosphere ◽  
Optical Emission ◽  
Temporal Variations ◽  
Eastern Siberia ◽  
Wind Dispersion ◽  
Fabry Perot ◽  
Mesosphere And Lower Thermosphere ◽  
Academy Of Sciences ◽  
Parameters Measurement

Abstract. In this paper, we study the response of the mesosphere and lower thermosphere (MLT) to sudden stratospheric warmings (SSWs) and the activity of stationary planetary waves (SPWs). We observe the 557.7-nm optical emission for retrieve the MLT wind, temperature with the Fabry-Perot interferometer (FPI) that has no analogues in Russia. The FPI is located at the mid-latitudes of Eastern Siberia within the Tory Observatory (TOR) at the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences (ISTP SB RAS, 51.8N, 103.1E). Regular interferometer monitoring started in Dec 2016. Here, we address the temporal variations in the 557.7-nm emission intensity, as well as the variations in wind, temperature, and their variability obtained by using the line parameters measurement during the 2016–2020 winters. Both SSWs and SPWs appear to have equally strong effects in the upper atmosphere. When the 557.7-nm emission decreases due to some influences from below (SSWs or SPWs), the temperature variation observed by using this line and the temperature itself increase significantly. The zonal wind dispersion does not show significant SPW- and SSW-correlated variations, but the dominant zonal wind reverses during major SSW events the same as the averaged zonal wind at 60N in the stratosphere does without significant delays.

Observations of migrating tides in the mid-latitude MLT using an array of SuperDARN HF-radars

2020 ◽  
Author(s):  
Willem E. van Caspel ◽  
Patrick J. Espy ◽  
Robert E. Hibbins ◽  
John P. McCormack
Keyword(s):  
Lower Thermosphere ◽  
Atmospheric Tides ◽  
Horizontal Wind ◽  
Meteor Radar ◽  
Planetary Scale ◽  
Global Environmental ◽  
Synoptic Wind ◽  
Single Station ◽  
Wind Measurements ◽  
Wave Surfaces

<p>Solar thermal (migrating) atmospheric tides play an important role in shaping the day-to-day and seasonal variability of the Mesosphere-Lower-Thermosphere (MLT) region. Due the planetary scale of the migrating tides, observations have, however, remained sparse. This study uses meteor-echo wind measurements from a longitudinal array of SuperDARN HF-radars to isolate the amplitude and phase of the migrating diurnal, semidiurnal, and terdiurnal tide. The array of SuperDARN radars, covering nearly 180 degrees longitude at 60±5 degrees North, provide hourly horizontal wind measurements at approximately 95km altitude. The migrating components of the tides are isolated by fitting wave surfaces in space and time. The results are compared with global synoptic wind analyses from the high-altitude version of the Navy Global Environmental Model (NAVGEM-HA) to validate the method. The tides are also compared against those measured at a single station by the Trondheim (66N, 10E) meteor radar. We will present the method, a comparison between (migrating) tidal components in SuperDARN, NAVGEM-HA and the Trondheim meteor radar between 2014 and 2015, and migrating tide climatologies based on 21 years of SuperDARN data.</p>

scholarly journals Retrieving horizontally resolved wind fields using multi-static meteor radar observations

2018 ◽  
Author(s):  
Gunter Stober ◽  
Jorge L. Chau ◽  
Juha Vierinen ◽  
Christoph Jacobi ◽  
Sven Wilhelm
Keyword(s):  
Continuous Wave ◽  
Lower Thermosphere ◽  
Horizontal Wind ◽  
Retrieval Algorithm ◽  
Meteor Radar ◽  
Wind Fields ◽  
Wind Retrieval ◽  
Radar Network ◽  
Frequency Agile ◽  
Kinematic Properties

Abstract. Recently, the MMARIA (Multi-static, multi-frequency Agile Radar for Investigations of the Atmosphere) concept of a multi-static VHF meteor radar network to derive horizontally resolved wind fields in the mesosphere/lower thermosphere was introduced. Here we present preliminary results of the MMARIA network above Eastern Germany using two transmitters located at Juliusruh and Collm, and 5 receiving links two monostatic and three multi-static). The observations are complemented during a one-week campaign, with a couple of addition continuous-wave coded transmitters, making a total of 7 multi-static links. In order to access the kinematic properties of non-homogenous wind fields we developed a wind retrieval algorithm that applies regularization to determine the non-linear wind field in the altitude range of 82–98 km. The derived horizontally resolved wind fields are compared to wind fields retrieved by a more established volume velocity processing that includes the horizontal gradients of the horizontal wind components. The potential of such observations and the new retrieval to investigate gravity waves with horizontal scales between 50–200 km is presented and discussed.

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