Verification of the flow regimes based on high fidelity observations of bright meteors

TL;DR

This study validates flow regimes of centimeter-sized meteoroids using combined infrasound and optical data, demonstrating the importance of multiple fluid dynamic parameters for accurate analysis.

Contribution

First observational validation of meteoroid flow regimes in this size range using infrasound and optical data, comparing two evaluation approaches.

Findings

Flow regimes can be validated from observations.

Combination of dimensionless parameters improves analysis.

First validation for this meteoroid size range.

Abstract

Infrasound monitoring has proved to be effective in detection of the meteor generated shock waves. When combined with optical observations of meteors, this technique is also reliable for detecting centimeter-sized meteoroids that usually ablate at high altitudes, thus offering relevant clues that open the exploration of the meteoroid flight regimes. Since a shock wave is formed as a result of a passage of the meteoroid through the atmosphere, the knowledge of the physical parameters of the surrounding gas around the meteoroid surface can be used to determine the meteor flow regime. This study analyses the flow regimes of a data set of twenty-four centimeter-sized meteoroids for which well constrained infrasound and photometric information is available. This is the first time that the flow regimes for meteoroids in this size range are validated from observations. From our approach, the Knudsen and Reynolds numbers are calculated, and two different flow regime evaluation approaches are compared in order to validate the theoretical formulation. The results demonstrate that a combination of fluid dynamic dimensionless parameters is needed to allow a better inclusion of the local physical processes of the phenomena.