S244 Impacts of sea surface temperatures on 2017 hurricanes

Sunday, 6 January 2019
Hall 4 (Phoenix Convention Center - West and North Buildings)
María Morales, University of Puerto Rico at Mayaguez, Mayaguez, PR, United States Minor Outlying Islands; and X. Chen and F. Zhang
Manuscript (75.9 kB)

The 2017 Hurricane Season was the seventh most intense hurricane season in the Atlantic
basin since 1850. As the costliest tropical cyclone season on record (≥ $368.66 billion), most of
the damages were caused by 3 major hurricanes: Harvey, Maria, and Irma. The sea surface
temperature (SST) along the paths of tropical cyclones (TC) is one of the major factors that
influencing the intensity of hurricanes. In this study, we use the Weather Research and Forecasting
(WRF) model to investigate the impacts of sea surface temperature on the intensity of the 2017
hurricanes through the SST sensitivity experiments. Two convection-permitting simulations are
performed here with the control simulation using the 2017 SST and the sensitivity simulation using
the mean SST averaged over 2001 to 2016 as the lower boundary condition. The SST over the
Atlantic basin during the summer of 2017 is about 0.5 to 1 K warmer than 16-yrs mean but with
great spatial variability. The results show that the warmer SST along the TC tracks increases the
destructiveness of hurricanes. The spatial pattern of the SST also has considerable impacts on the
hurricane structure. For example, for Hurricane Irma, the eyewall size becomes smaller in the
control simulation. The power dissipation index (PDI) and destructive potential (PDS) are
calculated in this study. These two index show that different hurricanes’ intensity change
differently when the SST is replaced by the 16-yrs mean. The major hurricanes Harvey, Irma and
Maria show higher intensify with the 2001-2016 SST.
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