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| Titel |
Probabilistic infrasound propagation using ensemble based atmospheric perturbations |
| VerfasserIn |
Pieter Smets, Läslo Evers |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110678
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| Publikation (Nr.) |
 EGU/EGU2015-10705.pdf |
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| Zusammenfassung |
| The state of the atmosphere is of utmost importance for infrasound propagation. In
propagation modelling, still, the true state of the atmosphere is mainly represented by the
analysis. The analysis is the best deterministic estimate of the atmosphere using a data
assimilation system existing of a General Circulation Model (GCM). However, the analysis
excludes error variances of both model and observations. In addition, the coarse resolution of
GCM results in averaging of, e.g., clouds or gravity waves, over larger regions known as
parameterisation. Consequentially, arrivals due to fine-scale structure in wind and
temperature can be missing.
Therefore, infrasound propagation including the atmospheric best-estimate error
variances based on the ensemble model is proposed. The ensemble system exists of model
perturbations with an amplitude comparable to analysis error estimates to obtain a probability
density function rather than one specific state as obtained from a deterministic system. The
best-estimate analysis error variances are described by a set of perturbations using the
European Centre for Medium-range Weather Forecasts (ECMWF) Ensemble Data
Assimilation (EDA) system.
Probabilistic infrasound propagation using 3–D ray tracing is demonstrated by one year
of mining activity, e.g., blasting, in Gällivare, northern Sweden, observed at infrasound array
IS37 in Norway, part of the International Monitoring System (IMS) for verification of
the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Probabilistic infrasound
propagation is compared with the standard deterministic result obtained using the analysis. |
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