Tornado damage analysis of a forest area using site survey observations, radar data and a simple analytical vortex model

Bech, Joan; Gayà, Miquel; Aran, Montserrat; Figuerola, Francesc; Amaro, J.; Arús, Joan

doi:10.1016/j.atmosres.2008.10.016

Cited by 36 publications

(43 citation statements)

References 34 publications

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“… Rotation-translation ratio (G max ): The G max parameter was estimated to range from 4.5 to 5.0. These values are close to those found in observed tornado tree fall studies that estimated G max (Beck and Dotzek 2010;Bech et al 2009). …”

Section: Comparisons Using Rankine Vortex (Input) Parameterssupporting

confidence: 76%

See 1 more Smart Citation

Draft final report, National Institute of Standards and Technology (NIST) Technical investigation of the May 22, 2011 tornado in Joplin, Missouri

Kuligowski¹,

Lombardo²,

Phan³

et al. 2013

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Section: Comparisons Using Rankine Vortex (Input) Parameterssupporting

confidence: 76%

“…Similar to α, initial ranges for G max were based on comparing tree fall patterns in previous literature and other tornado events (Beck and Dotzek 2010;Holland et al 2006;Bech 2009) with the patterns observed in Joplin. The prior studies suggested a G max value between 3.0 and 5.0.…”

Section: Joplin Tornado Model Initialization-mentioning

confidence: 99%

Draft final report, National Institute of Standards and Technology (NIST) Technical investigation of the May 22, 2011 tornado in Joplin, Missouri

Kuligowski¹,

Lombardo²,

Phan³

et al. 2013

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“…The wind field module produces an instantaneous velocity at each grid point that is compared with y crit . If the instantaneous velocity of the wind field exceeds y crit , the tree is considered to be downed, and the fall direction is assumed to be the instantaneous direction of the wind field at the corresponding point, in accordance with Letzmann (1923), Holland et al (2006), and Bech et al (2009).…”

Section: B Tree Damage Modelmentioning

confidence: 99%

“…Some of these had also made brief reference to Letzmann's work, similar to Holland et al (2006). More recently, Letzmann's work was credited by Lee and Wurman (2005) and Wurman and Alexander (2005) as well as Bech et al (2007Bech et al ( , 2009, who performed a simulation of the forest damage of the Castellcir, Spain, tornado, which will also serve as a case study here.…”

Section: Introductionmentioning

confidence: 97%

Reconstruction of Near-Surface Tornado Wind Fields from Forest Damage

Beck

Dotzek

2010

Journal of Applied Meteorology and Climatology

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Tornado intensity is usually inferred from the damage produced. To foster postevent tornado intensity assessments, the authors present a model to reconstruct near-surface wind fields from forest damage patterns. By comparing the structure of observed and simulated damage patterns, essential parameters to describe a tornado near-surface wind field are derived, such as the ratio G max between circular and translational velocity, and the deflection angle a between peak wind and pressure gradient. The model consists of a wind field module following the Letzmann analytical tornado model and a tree module based on the mechanistic HWIND tree model to assess tree breakage. Using this method, the velocity components of the near-surface wind field, the track of the tornado center, and the spatial distribution of the Fujita scale along and across the damage path can be assessed. Necessary requirements to apply the model are knowledge of the tornado translation speed (e.g., from radar observations) and a detailed analysis of the forest damage patterns. One of the key findings of this analysis is that the maximum intensity of the tornado is determinable with an uncertainty of only (G max 1 1) times the variability of the usually well-known tornado translation speed. Further, if Letzmann's model is applied and the translation speed of the tornado is known, the detailed tree model is unnecessary and could be replaced by an average critical velocity for stem breakage y crit independent of the tree species. Under this framework, the F3 and F2 ratings of the tornadoes in Milosovice, Czech Republic, on 30 May 2001 and Castellcir, Spain, on 18 October 2006, respectively, could be verified. For the Milosovice event, the uncertainty in peak intensity was only 66.0 m s 21 . Additional information about the structure of the near-surface wind field in the tornado and several secondary vortices was also gained. Further, this model allows for distinguishing downburst damage patterns from those of tornadoes.

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“…European meteorologists Wegener and more specifically Letzmann studied patterns of tree fall in European tornadoes and created theoretical fall patterns (Peterson, 1992). The models created from the work of Letzmann went largely unexplored until recently (Bech et al, 2009;Beck and Dotzek, 2010;Holland et al, 2006;Karstens et al, 2013;Peterson, 2003).…”

Section: Historymentioning

confidence: 97%

Comparison of two methods of near-surface wind speed estimation in the 22 May, 2011 Joplin, Missouri Tornado

Lombardo

Roueche

Prevatt

2015

Journal of Wind Engineering and Industrial Aerodynamics

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Tornado damage analysis of a forest area using site survey observations, radar data and a simple analytical vortex model

Cited by 36 publications

References 34 publications

Draft final report, National Institute of Standards and Technology (NIST) Technical investigation of the May 22, 2011 tornado in Joplin, Missouri

Draft final report, National Institute of Standards and Technology (NIST) Technical investigation of the May 22, 2011 tornado in Joplin, Missouri

Reconstruction of Near-Surface Tornado Wind Fields from Forest Damage

Comparison of two methods of near-surface wind speed estimation in the 22 May, 2011 Joplin, Missouri Tornado

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