The improvement to the environmental wind and tropical cyclone circulation retrievals with the modified GBVTD (MGBVTD) technique
Journal
Journal of Applied Meteorology and Climatology
Journal Volume
52
Journal Issue
11
Pages
2493-2508
Date Issued
2013
Author(s)
Abstract
The 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 VM cannot be resolved and is consequently aliased into the retrieved axisymmetric tangential wind VT0. Recently, the development of the hurricane volume velocity processing method (HVVP) enabled the independent estimation of VM; however, HVVP is potentially limited by the unknown accuracy of empirical assumptions used to deduce the modified Rankine-combined vortex exponent XT. By combing the GBVTD with HVVP techniques, this study proposes a modified GBVTD method (MGBVTD) to objectively deduce XT from theGBVTDtechnique and provide amore accurate estimation of VM and VT0 via an iterative procedure to reach converged VT0 and cross-beamcomponent of VM 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 VM is within 2ms-1 of reality. MGBVTD was applied to Hurricane Bret (1999) whose inner core was captured simultaneously by twoWeather Surveillance Radar-1988 Doppler (WSR-88D) instruments. The MGBVTD-retrieved cross-beam component of VM from single-Doppler radar data is very close to that from dual-Doppler radar synthesis using extended GBVTD (EGBVTD); their difference is less than 2ms-1. Themean difference in theMGBVTD-retrieved VT0 from the two radars is ~2ms21, which is significantly smaller than that resolved in GBVTD retrievals (~5ms-1). © 2013 American Meteorological Society.
SDGs
Other Subjects
Accurate estimation; Ground based; Hurricane Bret; Landfalling tropical cyclones; Tangential wind; Track display; Tropical cyclone; Volume velocity processing; Doppler radar; Hurricane effects; Surveillance radar; Iterative methods; atmospheric circulation; climate modeling; Doppler radar; ground-based measurement; numerical model; storm track; three-dimensional modeling; tropical cyclone; weather forecasting; wind field; wind velocity
Type
journal article