Characteristics of a Subtropical Squall Line Determined from TAMEX Dual-Doppler Data. Part I: Kinematic Structure

Abstract A velocity dealiasing algorithm is developed for C-band (5-cm wavelength) Doppler radars. With the shorter wavelength, C-band radars operating in a single PRF mode have a Nyquist interval about one-half that of S-band radars. As a proxy for C-band radar data, S-band Doppler data were sampled to produce radial velocity patterns as they would have been observed by a C-band Doppler radar. This algorithm includes six modules, some of which are modifications to previously existing methods. The modules (i) remove weak signals and determine the reference radials and dealias the radial wind field with a continuity constraint, (ii) perform a bulk continuity check, (iii) perform a “box” check to provide local consistency, (iv) perform a linear consistency fit in the radial direction, (v) provide quadratic least squares fit in the azimuthal direction, and (vi) perform quadratic least squares fit for elevation angle above 6.0° only for data from typhoons. The proposed dealiasing algorithm was tested on data from four typhoons and one squall line observed in China. When compared to the dealiasing results of the synthetic C-band data by the existing Next Generation Weather Radar (NEXRAD) algorithm, it was consistently better, particularly with smaller Nyquist cointervals. The algorithm correctly dealiased 91.56% of the aliased radial velocity data in all test cases.

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Wind Structure of a Subtropical Squall Line in China: Results from Dual-Doppler Radar Data

Advances in Meteorology ◽

10.1155/2016/9059383 ◽

2016 ◽

Vol 2016 ◽

pp. 1-18

Author(s):

Haiguang Zhou

Keyword(s):

Doppler Radar ◽

Three Dimensional ◽

Leading Edge ◽

Heavy Precipitation ◽

Radar Data ◽

Squall Line ◽

Stratiform Region ◽

Convective Region ◽

Doppler Data ◽

Mature Period

A subtropical squall line moved from Guangxi to Guangdong province in South China on 23-24 April 2007, which resulted in gale and heavy precipitation. The three-dimensional (3D) wind field of the squall line in its mature period was retrieved by Guangzhou-Shenzhen dual-Doppler data. The 3D conceptual model of this squall line was proposed. On the horizontal plane, the storm-relative front-to-rear inflow prevailed at the lower altitudes of the leading edge. The rear-to-front cold inflow in the stratiform region was observed below 3 km height, which enhanced the convergence in the convective region. At the middle altitudes of the squall line, the front-to-rear horizontal flow prevailed. Strong updrafts were observed at the lower and middle altitudes of the leading edge. Some convergence centers were located at the lower altitudes of the convective region. Furthermore, the storm-relative flow in the vertical cross-section perpendicular to the squall line was revealed. The front-to-rear warm flow extended from the surface to 7.5 km altitude at the leading edge. Above it, part of the front-to-rear inflow blew upward and then forward, and the other part of the inflow blew backward. The descending rear-to-front cold flow was only seen below 3 km height in the stratiform region.

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Electrical and Kinematic Structure of the Stratiform Precipitation Region Trailing an Oklahoma Squall Line

Journal of the Atmospheric Sciences ◽

10.1175/1520-0469(1991)048<0825:eaksot>2.0.co;2 ◽

1991 ◽

Vol 48 (6) ◽

pp. 825-842 ◽

Cited By ~ 34

Author(s):

Terry J. Schuur ◽

W. David Rust ◽

Bradley F. Smull ◽

Thomas C. Marshall

Keyword(s):

Squall Line ◽

Kinematic Structure ◽

Precipitation Region ◽

Stratiform Precipitation

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Characteristics of a Subtropical Squall Line Determined from TAMEX Dual-Doppler Data. Part II: Dynamic and Thermodynamic Structures and Momentum Budgets

Journal of the Atmospheric Sciences ◽

10.1175/1520-0469(1990)047<2382:coassl>2.0.co;2 ◽

1990 ◽

Vol 47 (20) ◽

pp. 2382-2399 ◽

Cited By ~ 11

Author(s):

Yeong-Jer Lin ◽

Hsi Shen ◽

Tai-Chi Chen Wang ◽

Zen-Sing Deng ◽

Robert W. Pasken

Keyword(s):

Squall Line ◽

Doppler Data

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Kinematic structure of the inner zones of disc galaxies

EAS Publications Series ◽

10.1051/eas:2003127 ◽

2003 ◽

Vol 10 ◽

pp. 37-37

Author(s):

J. C. Vega Beltrán ◽

P. Erwin ◽

J. Beckman

Keyword(s):

Kinematic Structure ◽

Disc Galaxies

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Design of a Human Knee Reeducation Mechanism

Acta Universitatis Sapientiae Electrical and Mechanical Engineering ◽

10.2478/auseme-2019-0004 ◽

2019 ◽

Vol 11 (1) ◽

pp. 42-53

Author(s):

Allaoua Brahmia ◽

Ridha Kelaiaia

Keyword(s):

Lower Limb ◽

Mechanical Design ◽

Kinematic Chain ◽

Lower Limbs ◽

Kinematic Structure ◽

Robotic Device ◽

Human Knee ◽

Kinematic Study ◽

Rehabilitation Exercise ◽

New Machine

Abstract To establish an exercise in open muscular chain rehabilitation (OMC), it is necessary to choose the type of kinematic chain of the mechanical / biomechanical system that constitutes the lower limbs in interaction with the robotic device. Indeed, it’s accepted in biomechanics that a rehabilitation exercise in OMC of the lower limb is performed with a fixed hip and a free foot. Based on these findings, a kinematic structure of a new machine, named Reeduc-Knee, is proposed, and a mechanical design is carried out. The contribution of this work is not limited to the mechanical design of the Reeduc-Knee system. Indeed, to define the minimum parameterizing defining the configuration of the device relative to an absolute reference, a geometric and kinematic study is presented.

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