Low-Wavenumber Structure and Evolution of the Hurricane Inner Core Observed by Airborne Dual-Doppler Radar

2000 ◽  
Vol 128 (6) ◽  
pp. 1653-1680 ◽  
Author(s):  
Paul D. Reasor ◽  
Michael T. Montgomery ◽  
Frank D. Marks ◽  
John F. Gamache
Keyword(s):  
Inner Core ◽  
Doppler Radar ◽  
Dual Doppler Radar

NSSL Dual-Doppler Radar Measurements in Tornadic Storms: a Preview

1975 ◽  
Vol 56 (5) ◽  
pp. 524-526 ◽  
Author(s):  
Rodger A. Brown ◽  
Donald W. Burgess ◽  
John K. Carter ◽  
Leslie R. Lemon ◽  
Dale Sirmans
Keyword(s):  
Doppler Radar ◽  
Radar Measurements ◽  
Tornadic Storms ◽  
Dual Doppler Radar

scholarly journals Vertical Vortex Development in Hurricane Michael (2018) during Rapid Intensification

2021 ◽  
Author(s):  
Alexander J. DesRosiers ◽  
Michael M. Bell ◽  
Ting-Yu Cha
Keyword(s):  
Inner Core ◽  
Doppler Radar ◽  
Three Dimensional ◽  
Vertical Gradient ◽  
Machine Learning Techniques ◽  
Rapid Intensification ◽  
Wind Retrieval ◽  
Retrieval Technique ◽  
Budget Analysis ◽  
Tangential Wind

AbstractThe landfall of Hurricane Michael (2018) at category 5 intensity occurred after rapid intensification (RI) spanning much of the storm’s lifetime. Four Hurricane Hunter aircraft missions observed the RI period with tail Doppler radar (TDR). Data from each of the 14 aircraft passes through the storm were quality controlled via a combination of interactive and machine learning techniques. TDR data from each pass were synthesized using the SAMURAI variational wind retrieval technique to yield three-dimensional kinematic fields of the storm to examine inner core processes during RI. Vorticity and angular momentum increased and concentrated in the eyewall region. A vorticity budget analysis indicates the tendencies became more axisymmetric over time. In this study we focus in particular on how the eyewall vorticity tower builds vertically into the upper levels. Horizontal vorticity associated with the vertical gradient of tangential wind was tilted into the vertical by the eyewall updraft to yield a positive vertical vorticity tendency inward atop the existing vorticity tower, that is further developed locally upward and outward along the sloped eyewall through advection and stretching. Observed maintenance of thermal wind balance from a thermodynamic retrieval shows evidence of a strengthening warm core, which aided in lowering surface pressure and further contributed to the efficient intensification in the latter stages of this RI event.

scholarly journals A Comparison of HWRF Six-Hourly 4DEnVar and Hourly 3DEnVar Assimilation of Inner Core Tail Dopper Radar Observations for the Prediction of Hurricane Edouard (2014)

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 942
Author(s):  
Benjamin Davis ◽  
Xuguang Wang ◽  
Xu Lu
Keyword(s):  
Inner Core ◽  
Doppler Radar ◽  
Three Dimensional ◽  
Weather Research And Forecasting ◽  
Location Error ◽  
Background Error ◽  
Error Covariance ◽  
Storm Center ◽  
The One ◽  
Better Than

Six-hourly three-dimensional ensemble variational (3DEnVar) (6H-3DEnVar) data assimilation (DA) assumes constant background error covariance (BEC) during a six-hour DA window and is, therefore, unable to account for temporal evolution of the BEC. This study evaluates the one-hourly 3DEnVar (1H-3DEnVar) and six-hourly 4DEnVar (6H-4DEnVar) DA methods for the analyses and forecasts of hurricanes with rapidly evolving BEC. Both methods account for evolving BEC in a hybrid EnVar DA system. In order to compare these methods, experiments are conducted by assimilating inner core Tail Doppler Radar (TDR) wind for Hurricane Edouard (2014) and by running the Hurricane Weather Research and Forecasting (HWRF) model. In most metrics, 1H-3DEnVar and 6H-4DEnVar analyses and forecasts verify better than 6H-3DEnVar. 6H-4DEnVar produces better thermodynamic analyses than 1H-3DEnVar. Radar reflectivity shows that 1H-3DEnVar produces better structure forecasts. For the first 24–48 h of the intensity forecast, 6H-4DEnVar forecast performs better than 1H-3DEnVar verified against the best track. Degraded 1H-3DEnVar forecasts are found to be associated with background storm center location error as a result of underdispersive ensemble storm center spread. Removing location error in the background improves intensity forecasts of 1H-3DEnVar.

Severe Thunderstorm Internal Structure from Dual-Doppler Radar Measurements

1977 ◽  
Vol 16 (10) ◽  
pp. 1036-1048 ◽  
Author(s):  
Joe R. Eagleman ◽  
Wen C. Lin
Keyword(s):  
Theoretical Model ◽  
Internal Structure ◽  
Doppler Radar ◽  
Radar Data ◽  
Severe Thunderstorm ◽  
Radar Measurements ◽  
Vertical Winds ◽  
Relationship Of ◽  
The Relationship ◽  
Dual Doppler Radar

Abstract Dual-Doppler radar data were analyzed for three different times during the life cycle of a severe thunderstorm. The thunderstorm developed a double vortex inside as a tornado was generated beneath the cloud.The organized kinematic and precipitation internal structure of the thunderstorm support a theoreticaldouble-vortex thunderstorm model that was developed earlier. The horizontal perturbation and relativewinds, vertical winds, horizontal divergence and vorticity are compared for the three different times ofmeasurement. The measurements and theoretical model provide new explanations of the severe thunderstorm and the relationship of associated tornadoes.

Error Estimation in Wind Fields Derived from Dual-Doppler Radar Measurement

1976 ◽  
Vol 15 (8) ◽  
pp. 868-878 ◽  
Author(s):  
Richard J. Doviak ◽  
Peter S. Ray ◽  
Richard G. Strauch ◽  
L. Jay Miller
Keyword(s):  
Error Estimation ◽  
Doppler Radar ◽  
Wind Fields ◽  
Radar Measurement ◽  
Dual Doppler Radar

The Improvement to the Environmental Wind and Tropical Cyclone Circulation Retrievals with the Modified GBVTD (MGBVTD) Technique

2013 ◽  
Vol 52 (11) ◽  
pp. 2493-2508 ◽  
Author(s):  
Xiaomin Chen ◽  
Kun Zhao ◽  
Wen-Chau Lee ◽  
Ben Jong-Dao Jou ◽  
Ming Xue ◽  
...  
Keyword(s):  
Inner Core ◽  
Doppler Radar ◽  
Three Dimensional ◽  
Radar Data ◽  
Accurate Estimation ◽  
Doppler Radar Data ◽  
Tangential Wind ◽  
The Mean ◽  
Landfalling Tropical Cyclones ◽  
Beam Component

AbstractThe ground-based velocity track display (GBVTD) was developed to deduce a three-dimensional primary circulation of landfalling tropical cyclones from single-Doppler radar data. However, the cross-beam component of the mean wind cannot be resolved and is consequently aliased into the retrieved axisymmetric tangential wind . Recently, the development of the hurricane volume velocity processing method (HVVP) enabled the independent estimation of ; however, HVVP is potentially limited by the unknown accuracy of empirical assumptions used to deduce the modified Rankine-combined vortex exponent . By combing the GBVTD with HVVP techniques, this study proposes a modified GBVTD method (MGBVTD) to objectively deduce from the GBVTD technique and provide a more accurate estimation of and via an iterative procedure to reach converged and cross-beam component of solutions. MGBVTD retains the strength of both algorithms but avoids their weaknesses. The results from idealized experiments demonstrate that the MGBVTD-retrieved cross-beam component of is within 2 m s−1 of reality. MGBVTD was applied to Hurricane Bret (1999) whose inner core was captured simultaneously by two Weather Surveillance Radar-1988 Doppler (WSR-88D) instruments. The MGBVTD-retrieved cross-beam component of from single-Doppler radar data is very close to that from dual-Doppler radar synthesis using extended GBVTD (EGBVTD); their difference is less than 2 m s−1. The mean difference in the MGBVTD-retrieved from the two radars is ~2 m s−1, which is significantly smaller than that resolved in GBVTD retrievals (~5 m s−1).

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