<p>Here we investigate tropical cyclone (TC) activity and intensity within a 100km radius of Bermuda between 1955 and 2019. Our results show a more easterly genesis over time and significant increasing trends in tropical cyclone intensity (maximum wind speed (Vmax)) with a decadal Vmax median value increase of 30kts from 33 to 63kts, together with significant increasing August, September, October (ASO) sea surface temperature (SST) of 1.1&#176;C (0.17 &#176;C per decade) &#160;and ocean temperature between 0.5&#8211;0.7&#176;C (0.08-0.1&#176;C per decade) &#160;in the depth range 0-300m. The strongest correlation is found between TC intensity and ocean temperature averaged through the top 50m ocean layer (T<sub>50m</sub>) r=0.37 (p<0.01).&#160;</p><p>We show how tropical cyclone potential intensity estimates are closer to actual intensity by using T<sub>50m</sub> opposed to SST using the Bermuda Atlantic Timeseries Hydrostation S dataset. We modify the widely used sea surface temperature potential intensity index by using T<sub>50m</sub>&#160;to provide a closer estimate of the observed minimum sea level pressure (MSLP), and associated Vmax than by using SST, creating a T<sub>50m&#160;</sub>potential&#160;intensity (T<sub>50m</sub>_PI) index. The average MSLP difference is reduced by 12mb and proportional to the SST/ T<sub>50m </sub>temperature difference. We also suggest the index could be used over a wider area of the subtropical/tropical Atlantic where there is a shallow mixed layer depth. Finally, we outline the TC wind-pressure relationship observed for the subtropical Atlantic around Bermuda, explaining 77% of the variance, which may prove useful for future prediction.</p><p>(Environmental Research Letters, 2020, in revision)</p><p>&#160;</p><p>&#160;</p>
Effects of surface heat flux-induced sea surface temperature changes on tropical cyclone intensity
