Garcia-Franco, JL and Schwendike, J (2021) Revisiting gradient wind balance in tropical cyclones using dropsonde observations. Quarterly Journal of the Royal Meteorological Society, 147 (735). pp. 801-824. ISSN 0035-9009
Abstract
This study diagnoses the degree of gradient wind balance (GWB) in dropsonde observations of 30 tropical cyclones (TCs) divided into 91 intense observation periods. The diagnosed GWB in these observation periods are composited to investigate which characteristics of a TC are significantly related to departures from GWB. This analysis confirms that on average the flow above the boundary layer is approximately in GWB. Supergradient flow is more common near the radius of maximum wind (RMW) in the upper boundary layer than above in the free troposphere or outside the RMW and is also more common in strong storms than in weak storms. In contrast, the degree of GWB does not differ between intensifying, steady‐state and weakening storms. Storms with a peaked wind profile have a higher probability of showing supergradient winds than those with a flat wind profile. The comparison of two commonly used functions to fit observations shows that the diagnosing GWB from dropsonde observations is highly dependent on the analysis technique. The agradient wind magnitude and even sign is shown to depend on which of these functions is used to fit the observations. The use of a polynomial fit consistently diagnoses the presence of supergradient winds far more frequently than a piece‐wise function, and also shows a marked degree of imbalance above the boundary layer. Therefore, caution is warranted when determining the degree of GWB with a polynomial fit.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 Royal Meteorological Society. This is the peer reviewed version of the following article: García‐Franco, JL, Schwendike, J. Revisiting gradient wind balance in tropical cyclones using dropsonde observations. Q J R Meteorol Soc. 2021; 147: 801– 824., which has been published in final form at https://doi.org/10.1002/qj.3947. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. |
Keywords: | boundary layer; hurricanes; peaked wind profile; radius of maximum wind; subgradient flow; supergradient flow |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Nov 2020 11:13 |
Last Modified: | 13 Dec 2021 01:38 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/qj.3947 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:168000 |