edu.ucar.opensky::articles:25659 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T20:07:46.091099 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7wq07jh Supergradient winds in simulated tropical cyclones 2022-08-01T00:00:00Z publication https://n2t.org/ark:/85065/d7wq07jh https://doi.org/10.1175/JAS-D-21-0306.1 Rotunno, Richard author UCAR/NCAR - Library publisher In a previous paper a formula was derived for the maximum potential intensity of the tangential wind in a tropical cyclone called PI+. The formula, PI+2 = EPI2 + alpha r(m)w(m)eta(m), where EPI is the maximum potential intensity of the gradient wind and alpha r(m)w(m)eta(m) represents the supergradient winds. The latter term is the product of the radius r(m), the vertical velocity w(m), the azimuthal vorticity eta(m) at the radius and height of the maximum tangential wind (r(m), z(m)), and the (nearly constant) alpha. Examination of a series of simulations of idealized tropical cyclones indicate an increasing contribution from the supergradient-wind term to PI+ as the radius of maximum wind increases. In the present paper, the physical content of the supergradient-wind term is developed showing how it is directly related to tropical cyclone boundary layer dynamics. It is found that rmwm eta m PROP;umin2zm(rm)/l upsilon(zm) PROP;rm, where -u(min) is the maximum boundary layer radial inflow velocity and l(upsilon)(z) is the vertical mixing length. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2022 American Meteorological Society (AMS). None eng geoscientificInformation