James B. Elsner, Sarah E. Strazzo, Thomas H. Jagger, Timothy LaRow, Ming Zhao

Published date August 6, 2013

Sensitivity of Limiting Hurricane Intensity to SST in the Atlantic from Observations and GCMs

  • States that a statistical model for the intensity of the strongest hurricanes has been developed and a new methodology introduced for estimating the sensitivity of the strongest hurricanes to changes in sea surface temperature
  • Here, the authors use this methodology on observed hurricanes and hurricanes generated from two global climate models (GCMs)
  • Finds that hurricanes over the North Atlantic Ocean during the period 1981–2010 show a sensitivity of 7.9 ± 1.19 m s−1 K−1 (standard error; SE) when over seas warmer than 25°C
  • Finds, in contrast, that hurricanes over the same region and period generated from the GFDL High Resolution Atmospheric Model (HiRAM) show a significantly lower sensitivity with the highest at 1.8 ± 0.42 m s−1 K−1 (SE)
  • Finds similar weaker sensitivity using hurricanes generated from the Florida State University Center for Ocean–Atmospheric Prediction Studies (FSU-COAPS) model with the highest at 2.9 ± 2.64 m s−1 K−1 (SE)
  • Finds that a statistical refinement of HiRAM-generated hurricane intensities heightens the sensitivity to a maximum of 6.9 ± 3.33 m s−1 K−1 (SE), but the increase is offset by additional uncertainty associated with the refinement
  • Results suggest that the caution that should be exercised when interpreting GCM scenarios of future hurricane intensity stems from the low sensitivity of limiting GCM-generated hurricane intensity to ocean temperature

Figure: Limiting hurricane intensity as a function of SST based on the National Hurricane Center (NHC) best track. The line is a weighted regression where the weights are proportional to the number of hurricanes in each grid. The slope of the line is 7.9 m s21K21 and represents the sensitivity of LI to SST. The 95% confidence band about this slope is shown in gray. The 80% uncertainty about the per grid LI estimates is shown by the vertical lines.