Surface ocean warming near the core of hurricane Sam and its representation in forecast models

• DOI: 10.3389/fmars.2023.1297974
• Publication Date: 2024-01-08T05:54:25Z
• Authors: Andrew M. Chiodi; Hristina Hristova; Gregory R. Foltz; Jun A. Zhang; Calvin W. Mordy; Catherine R. Edwards; Chidong Zhang; Christian Meinig; Dongxiao Zhang; Edoardo Mazza; Edward D. Cokelet; Eugene F. Burger; Francis Bringas; Gustavo Goni; Hyun-Sook Kim; Sue Chen; Joaquin Triñanes; Kathleen Bailey; Kevin M. O’Brien; Maria Morales-Caez; Noah Lawrence-Slavas; Shuyi S. Chen; Xingchao Chen
• Keywords: Argo; Entrainment (biomusicology); Eye; Halocline; Atlantic hurricane; Mixed layer

On September 30, 2021, a saildrone uncrewed surface vehicle intercepted Hurricane Sam in the northwestern tropical Atlantic and provided continuous observations near eyewall. Measured ocean temperature unexpectedly increased during first half of storm. Saildrone current shear upper-ocean structure from nearest Argo profiles show an initial trapping wind momentum by strong halocline upper 30 m, followed deeper mixing entrainment warmer subsurface water into mixed layer. The conditions to operational forecast models failed capture observed structure. simulate warming developed cold bias ~0.5°C time peak winds were observed, resulting 12-17% underestimation enthalpy flux Results imply that enhanced and, critically, improved assimilation hurricane systems, could directly benefit intensity forecasts.