An Integrated Approach to Mid- and Upper-Level Turbulence Forecasting

Sharman, Robert; Tebaldi, Claudia; Wiener, Gerry; Wolff, Jamie K.

doi:10.1175/waf924.1

Cited by 196 publications

(282 citation statements)

References 35 publications

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“…Estimates of kinetic energy from subgrid scale models require knowledge of the Richardson number and the length scales of mixing and dissipation (Schumann, 1991), see Appendix A9, which is uncertain for NWP grids with grid scales far outside the inertial range. Turbulence experienced by cruising aircraft (including but not restricted to clear air turbulence) can be estimated from coarse NWP fields (Sharman et al, 2005;Frehlich and Sharman, 2010) but the scaling of this turbulence (composed of waves and turbulence) to plume scales has still to be investigated.…”

Section: The Turbulence Modelmentioning

confidence: 99%

A contrail cirrus prediction model

2012

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Abstract.A new model to simulate and predict the properties of a large ensemble of contrails as a function of given air traffic and meteorology is described. The model is designed for approximate prediction of contrail cirrus cover and analysis of contrail climate impact, e.g. within aviation system optimization processes. The model simulates the full contrail life-cycle. Contrail segments form between waypoints of individual aircraft tracks in sufficiently cold and humid air masses. The initial contrail properties depend on the aircraft. The advection and evolution of the contrails is followed with a Lagrangian Gaussian plume model. Mixing and bulk cloud processes are treated quasi analytically or with an effective numerical scheme. Contrails disappear when the bulk ice content is sublimating or precipitating. The model has been implemented in a "Contrail Cirrus Prediction Tool" (CoCiP). This paper describes the model assumptions, the equations for individual contrails, and the analysis-method for contrailcirrus cover derived from the optical depth of the ensemble of contrails and background cirrus. The model has been applied for a case study and compared to the results of other models and in-situ contrail measurements. The simple model reproduces a considerable part of observed contrail properties. Mid-aged contrails provide the largest contributions to the product of optical depth and contrail width, important for climate impact.

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Section: The Turbulence Modelmentioning

confidence: 99%

A contrail cirrus prediction model

2012

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“…An NCAR-developed clear-air turbulence forecast product, graphical turbulence guidance (GTG), is currently in operational use by the National Oceanic and Atmospheric Administration's Aviation Weather Center. In accordance with plans for the FAA's Next Generation Air Transportation System, additional capabilities for GTG are under development to enhance its ability to nowcast convectively-induced turbulence (CIT), that is, turbulence in and around storms, using data sources such as radar, satellite and numerical weather prediction (NWP) models (Sharman et al 2006;Williams et al 2008). In this section, we specifically focus on developing improved prediction of CIT.…”

Section: Understanding Convectively Induced Turbulencementioning

confidence: 99%

Enhanced spatiotemporal relational probability trees and forests

McGovern

Troutman

Brown

et al. 2012

Data Min Knowl Disc

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Many real world domains are inherently spatiotemporal in nature. In this work, we introduce significant enhancements to two spatiotemporal relational learning methods, the spatiotemporal relational probability tree and the spatiotemporal relational random forest, that increase their ability to learn using spatiotemporal data. We enabled the models to formulate questions on both objects and the scalar and vector fields within and around objects, allowing the models to differentiate based on the gradient, divergence, and curl and to recognize the shape of point clouds defined by fields. This enables the model to ask questions about the change of a shape over time or about its orientation. These additions are validated on several real-world hazardous weather datasets. We demonstrate that these additions enable the models to learn robust classifiers that outperform the versions without these new additions. In

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“…As of now most operationally used forecasting techniques infer clear-air turbulence (CAT) behaviour from larger scales resolved in the NWP models (e.g. Sharman et al, 2006;Gill and Buchanan, 2014). This methodology is based on widely accepted assumption that due to the turbulent energy cascade the presence (Wyngaard, 2010) of resolved scale turbulence is implying the presence of sub-scale turbulence.…”

Section: Introductionmentioning

confidence: 99%

“…This methodology is based on widely accepted assumption that due to the turbulent energy cascade the presence (Wyngaard, 2010) of resolved scale turbulence is implying the presence of sub-scale turbulence. However, NWP-based forecast is bound to generate errors and requires sophisticated statistical corrections (Williams, 2014;Sharman et al, 2006;Kim et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Retrieving atmospheric turbulence information from regular commercial aircraft using Mode-S and ADS-B

et al. 2016

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Abstract. Navigational information broadcast by commercial aircraft in the form of Mode-S EHS (Mode-S Enhanced Surveillance) and ADS-B (Automatic Dependent Surveillance-Broadcast) messages can be considered a new source of upper tropospheric and lower stratospheric turbulence estimates. A set of three processing methods is proposed and analysed using a quality record of turbulence encounters made by a research aircraft.The proposed methods are based on processing the vertical acceleration or the background wind into the eddy dissipation rate. Turbulence intensity can be estimated using the standard content of the Mode-S EHS/ADS-B.The results are based on a Mode-S EHS/ADS-B data set generated synthetically based on the transmissions from the research aircraft. This data set was validated using the overlapping record of the Mode-S EHS/ADS-B received from the same research aircraft. The turbulence intensity, meaning the eddy dissipation rate, obtained from the proposed methods based on the Mode-S EHS/ADS-B is compared with the value obtained using on-board accelerometer. The results of the comparison indicate the potential of the methods. The advantages and limitation of the presented approaches are discussed.

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An Integrated Approach to Mid- and Upper-Level Turbulence Forecasting

Cited by 196 publications

References 35 publications

A contrail cirrus prediction model

A contrail cirrus prediction model

Enhanced spatiotemporal relational probability trees and forests

Retrieving atmospheric turbulence information from regular commercial aircraft using Mode-S and ADS-B

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