Infrasound from tropospheric sources: Impact on mesopause temperature?

Pilger, Christoph; Bittner, Michael

doi:10.1016/j.jastp.2009.03.008

Cited by 16 publications

(8 citation statements)

References 25 publications

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“…This signal is also recorded later at Station 2. We suggest that the reason for the low-frequency infrasound signal recorded at Station 1 of the second part of the debris flow might be the frequency-dependency of atmospheric attenuation absorbing high-frequency sound more than low-frequency sound [ 15 ]. In contrast to the results of [ 40 ], which showed that the seismic signals of mass movements can be detected over the entire length of the channel, the seismic signals of the first time section could be only detected at Station 1 and the seismic signal of the debris flow was registered only at Station 2.…”

Section: Example Eventsmentioning

confidence: 99%

“…Infrasound waves are produced by the turbulent flow part of the mass movement [ 13 , 14 ]. These acoustic waves are detectable over large distances (several km) due to the frequency-dependency of atmospheric attenuation, which absorbs high-frequency (audible and ultra-) sound more than infrasound (<20 Hz) [ 15 ]). Infrasound signals produced by mass movements are generally in a relatively noise-free band in the low-frequency acoustic spectrum (≤20 Hz) where the main noise is induced by wind [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Automatic Identification of Alpine Mass Movements by a Combination of Seismic and Infrasound Sensors

Schimmel

Hübl

McArdell

et al. 2018

Sensors

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The automatic detection and identification of alpine mass movements such as debris flows, debris floods, or landslides have been of increasing importance for devising mitigation measures in densely populated and intensively used alpine regions. Since these mass movements emit characteristic seismic and acoustic waves in the low-frequency range (<30 Hz), several approaches have already been developed for detection and warning systems based on these signals. However, a combination of the two methods, for improving detection probability and reducing false alarms, is still applied rarely. This paper presents an update and extension of a previously published approach for a detection and identification system based on a combination of seismic and infrasound sensors. Furthermore, this work evaluates the possible early warning times at several test sites and aims to analyze the seismic and infrasound spectral signature produced by different sediment-related mass movements to identify the process type and estimate the magnitude of the event. Thus, this study presents an initial method for estimating the peak discharge and total volume of debris flows based on infrasound data. Tests on several catchments show that this system can detect and identify mass movements in real time directly at the sensor site with high accuracy and a low false alarm ratio.

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Section: Example Eventsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Automatic Identification of Alpine Mass Movements by a Combination of Seismic and Infrasound Sensors

Schimmel

Hübl

McArdell

et al. 2018

Sensors

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“…Infrasound can travel thousands of kilometres and remain detectable over such distances. This is due to the frequency dependency of atmospheric attenuation, absorbing high-frequency (audible and ultra-) sound more than low-frequency (infra-) sound (Pilger et al 2009). Past studies about infrasound signals produced by snow avalanches (Firstov et al 1992;Naugolnykh et al 2002) conclude that the infrasonic signals of snow avalanches are mainly produced by the turbulent motion at the avalanche front (powder cloud).…”

Section: Infrasound Signals Of Avalanchesmentioning

confidence: 99%

Automatic detection of avalanches: evaluation of three different approaches

Schimmel

Hübl

Koschuch³

et al. 2017

Nat Hazards

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Automated detection of snow avalanches is an important tool for avalanche forecasting and for assessing the effectiveness of avalanche control measures at bad visibility. Avalanche detection systems are usually based on infrasound, seismic, or radar signals. Within this study, we compared three different types of avalanche detection systems: one avalanche radar, one infrasound array system consisting of four infrasound sensors, and a newly developed single sensor infrasound system. A special focus is given to the new single sensor system, which is a low cost, easy to install system, originally designed for the detection of debris flows and debris floods. Within this work, we analysed how this single sensor system could be adapted to detect also snow avalanches. All three systems were installed close to a road near Ischgl (Tyrol, Austria) at the avalanche-exposed Paznaun Valley. The valley is endangered by two avalanche paths which are controlled by several avalanche towers. The radar system detected avalanches accurately and reliably but was limited to the particular avalanche path towards which the radar beam was directed. The infrasound array could detect avalanches from all surrounding avalanche paths, however, with a higher effort for installation. The newly tested single infrasound sensor system was significantly cheaper and easier to install than the other two systems. It could also detect avalanches form all directions, although without information about the direction. In summary, each of the three different systems was able to successfully detect avalanches and had its particular strengths and weaknesses, which should be considered according to the specific requirements of a particular practical application.

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“…Propagation modeling approaches utilized within this study are the parabolic equation (PE) algorithm of the software package InfraMAP [25] and the ray-tracing (RT) method HARPA/DLR [24], an enhanced version of the original HARPA ray-tracing program [28]. Realistic atmospheric background conditions are included in the modeling by the use of ECMWF model analysis data (www.ecmwf.int) combined with climatologies for horizontal wind and temperatures above 60 km (HWM07, see [29]; MSISE00, see [30]).…”

Section: Modelingmentioning

confidence: 99%

“…In Section 2 of this study, the observational setting of Ariane 5 rocket engine tests as a ground-truth source [23] and infrasound measurements on a line profile of microbarometers towards an infrasound array as measurement setting are described. Two different propagation models, a ray-tracing [24] and a parabolic equation approach [25], described in Section 3, are applied to study infrasonic source-to-receiver paths. Atmospheric background mod-els using ECMWF analysis data, climatologies and finescale gravity wave structures are included for a realistic estimation of wave ducting.…”

Section: Introductionmentioning

confidence: 99%

Application of Propagation Modeling to Verify and Discriminate Ground-Truth Infrasound Signals at Regional Distances

Pilger¹,

Streicher²,

Ceranna³

et al. 2013

InfraMatics

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An infrasound field campaign was performed in 2011/2012 utilizing single infrasound sensors along the great circle path between a known ground-truth source (Ariane 5 engine test facility, Lampoldshausen, Germany) and a regional receiver (German infrasound array IS26, Bavarian Forest) covering a distance of rough 320 km in total. The gathered recordings provide new insights in the infrasonic wave propagation at regional and near-source distances by comparing measured signals with modeling results within this study. Ray-tracing and parabolic equation approaches are utilized to model infrasound propagation from the ground-truth source to the line profile sensors and explain the obtained detections and non-detections. Modeling and observation results are compared by estimating their amplitude, quantifying amplitude deviations and also considering observed and calculated travel times and celerities. Modeling results show a significant influence of small-scale atmospheric variations in effective sound speed profiles on the propagation pattern, which results in varying tropospheric and stratospheric ducting behavior. A large number of gravity wave profiles are tested to investigate the influences of atmospheric dynamics on the infrasound wave field and improve the modeling results. The modeling is furthermore applied to a case of two potential, contemporaneous and closely spaced infrasound sources. Propagation modeling is used here to resolve the source ambiguity between a ground-based and a higher altitude source giving a strong preference to the latter with respect to the observed infrasonic signatures. The good agreement between modeling and observation results within this study successfully shows the benefit of applying infrasound propagation modeling to the validation of infrasound measurements, verification of ducting behavior and discrimination of infrasound sources.

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Infrasound from tropospheric sources: Impact on mesopause temperature?

Cited by 16 publications

References 25 publications

Automatic Identification of Alpine Mass Movements by a Combination of Seismic and Infrasound Sensors

Automatic Identification of Alpine Mass Movements by a Combination of Seismic and Infrasound Sensors

Automatic detection of avalanches: evaluation of three different approaches

Application of Propagation Modeling to Verify and Discriminate Ground-Truth Infrasound Signals at Regional Distances

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