Turbulent Characteristics in the Eye and Eyewall of Hurricane Ian (2022)

Details

• Journal Title:
  Monthly Weather Review
• Personal Author:
  Lin, Guo ; Zhang, Jun A. ; Cione, Joseph J. ; Wadler, Joshua B. ; Dobosy, Ronald
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; AOML (Atlantic Oceanographic and Meteorological Laboratory) ; ARL (Air Resources Laboratory) ; CIMAS (Cooperative Institute for Marine and Atmospheric Studies)
• Description:
  Accurate prediction of tropical cyclone (TC) intensity remains a significant challenge partially due to physics deficiencies in forecast models. Improvement of boundary layer physics in the turbulent ‘gray zone’ requires a better understanding of spatiotemporal variations of turbulent properties in low-level high-wind regions. To fill the gap, this study utilizes Anduril’s Altius 600, a small uncrewed aircraft system (sUAS), that collected data in the eye and eyewall regions of Cat-5 Hurricane Ian (2022) at altitudes below 1.4 km. The highest observed wind speed exceeded 105 m s−1 at 650 m altitude. The Altius measured turbulent kinetic energy (TKE) and momentum fluxes that were in good agreement with previous crewed aircraft observations. This study explores scale-awareness turbulent structure by quantifying turbulence-scale (100 m – 2 km) and mesoscale (2-10 km) contributions to the total flux and TKE. Results show that mesoscale eddies dominate the horizontal wind variances compared to turbulent eddies. The horizontal wind variances contribute 70 – 90% of the total TKE, while the vertical wind variances contribute 10 – 30% of the total TKE. Spectral and wavelet analyses demonstrate eddy scales from a few hundred meters up to 10 km, with unique distributions depending on where observations were taken (e.g., eye vs eyewall). These findings underscore the complex and multi-scale nature of TKE and momentum fluxes in intense hurricanes and highlight the critical need for advanced observational tools within the high wind, hurricane boundary layer environment.
• Source:
  Monthly Weather Review (2025)
• DOI:
  https://doi.org/10.1175/MWR-D-24-0163.1
• ISSN:
  0027-0644 ; 1520-0493
• Format:
  pdf
• Publisher:
  American Meteorological Society
• Document Type:
  Journal Article
• Rights Information:
  Other
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:8cebd73b6134e3347be08fb1d1549c037a2e64b64e1632c4fcf3dab13611ccafaa153203aada9af6605f531a6f33c97cbae55d939a708c69f18f96e5968bc6a5
• File Type: