A New Metric for Hurricane Destruction Potential

June 1, 2013 · 0 comments

Hurricanes Katrina (2005), Ike (2008), and Sandy (2012) have proven the Saffir-Simpson Scale is inadequate for expressing hurricane destructiveness. This is especially true for storm surge, which the original Category 1-5 wind damage potential rating scale wasn’t designed to classify.

As another Atlantic hurricane season begins, a study now accepted for publication in Monthly Weather Review introduces a new metric for measuring the destructive potential of tropical cyclones: Track Integrated Kinetic Energy. TIKE builds on the earlier concept of Integrated Kinetic Energy to represent destructive potential by computing a storm’s sustained wind field quadrant-by-quadrant along its entire track. Summing up the IKE values over the tropical cyclone’s lifecycle more accurately determines the potential for destruction, the study concludes.

Additionally, TIKE can be accumulated for all of a tropical cyclone basin’s storms in a given year to create “an important metric of that season,” the authors write in a summary of their research (to appear in an upcoming issue of the Bulletin of the AMS).

Vasu Misra, lead author of the study “The Track Integrated Kinetic Energy of the Atlantic Tropical Cyclones,” adds:

Existing metrics such as Accumulated Cyclone Energy (ACE) or the Power Dissipation Index (PDI) only consider the peak wind in the storm, which is difficult to measure and typically only covers a very small area and contributes little to storm surge and wave damage.  TIKE takes into account the wind forcing over a large area surrounding the storm and is therefore much more reliable as an objective measure of hurricane destructive potential. In effect TIKE accounts for the intensity, duration, size, and structure of the tropical cyclones.

The study by Misra and his colleagues also looks at seasonal and season-to-season as well geographic variations of TIKE. Among its findings:

  • TIKE peaks in September along with hurricane season overall, since that’s when the Atlantic Ocean is warm enough to fuel large and long-lived storms;
  • Very active hurricane seasons such as 2005 may not be the most destructive since some large and powerful hurricanes may be short-lived;
  • Annual variations in TIKE are related to sea surface temperature variations in both the equatorial Pacific (warmer temperatures there relate to lower TIKE in the Atlantic) and the Atlantic (its warmer temperatures relate to higher TIKE there).

The MWR article abstract is open to all readers, while subscribers can read the full Early Online Release on the AMS journals website.