Slow translation speed causes rapid collapse of northeast Pacific Hurricane Kenneth over cold core eddy
Journal
Geophysical Research Letters
Journal Volume
41
Journal Issue
21
Pages
7595-7601
Date Issued
2014
Author(s)
Walker, Nan D.
Leben, Robert R.
Pilley, Chet T.
Shannon, Michael
Herndon, Derrick C.
Pun, Iam-Fei
Gentemann, Chelle L.
Abstract
Abstract Category 4 Hurricane Kenneth (HK) experienced unpredicted rapid weakening when it stalled over a cold core eddy (CCE) on 19–20 September 2005, 2800 km SE of Hawaii. Maximum sea surface temperature (SST) cooling of 8–9°C and a minimum aerially averaged SST of 18.3°C (over 8750 km 2 ) characterized its cool wake. A 3‐D mixed‐layer model enabled estimation of enthalpy fluxes (latent and sensible heat), as well as the relative importance of slow translation speed ( U h ) compared with the preexisting CCE. As U h dropped below 1.5 m s −1 , enthalpy fluxes became negative, cutting off direct ocean energy flux to HK. Although HK's weakening was attributed to wind shear, our results indicate that slow U h and consequent intense SST cooling were the main causes. The tropical cyclone‐intensified CCE experienced rapid growth in magnitude (−6 to −40 cm), increased diameter (60 to 350 km), elevated chlorophyll a for 4 months, and 12 month longevity.
SDGs
Type
journal article