To Align or Not to Align? That Is the Question

Details

• Journal Title:
  Journal of Geophysical Research: Atmospheres
• Personal Author:
  Fischer, Michael S. ; Alvey, George R. ; Jariwala, Deelan ; Reasor, Paul D.
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; AOML (Atlantic Oceanographic and Meteorological Laboratory) ; CIMAS (Cooperative Institute for Marine and Atmospheric Studies)
• Description:
  Previous studies have shown that vertically misaligned circulations are commonly found in weaker tropical cyclones (TCs) below hurricane strength, whereas TCs of hurricane intensity more typically exhibit vertically aligned vortices. Thus an important step in the TC intensification process is achieving a vertically aligned circulation. The present study is the first to perform a comprehensive, observational comparison of how the TC vortex and convective characteristics differ between Quickly Aligning and Persistently Tilted TCs. Airborne Doppler radar analyses from the Tropical Cyclone Radar Archive of Doppler Analyses with Recentering (TC‐RADAR) revealed that Quickly Aligning TCs have stronger and more compact lower‐tropospheric circulations. Although the initial vortex tilt magnitudes are similar in Quickly Aligning and Persistently Tilted TCs, Quickly Aligning storms are characterized by a tilt direction that tends to be more cyclonically downwind of the vertical wind shear vector than their Persistently Tilted counterparts. Quickly Aligning TCs also exhibit more frequent and stronger ascent in the lower troposphere than Persistently Tilted TCs, both near the lower‐tropospheric TC center and beneath the displaced mid‐tropospheric vortex, whereas differences aloft were less pronounced. The environments of Quickly Aligning TCs feature weaker mid‐tropospheric vertical wind shear, greater column‐integrated precipitable water in a mesoscale domain near the low‐level circulation center (LLC), and larger maximum potential intensities than Persistently Tilted TCs. We hypothesize that, although convection is generally favored near the mid‐tropospheric TC center, enhanced lower‐tropospheric vertical mass fluxes, especially within 35-50 km of the LLC, drive changes in misalignment via vortex stretching and precession.
• Source:
  Journal of Geophysical Research: Atmospheres, 131(14)
• DOI:
  https://doi.org/10.1029/2025JD045986
• ISSN:
  2169-897X ; 2169-8996
• Format:
  PDF
• Publisher:
  American Geophysical Union (AGU)
• Document Type:
  Journal Article
• License:
  https://creativecommons.org/licenses/by/4.0/
• Rights Information:
  CC BY
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:eb4ba166c789c46157f406cb2e3b5038155805906bcca7dd0dfd809e946ad83e2f63a73cfdeaca492d2689d14271bc834e8e654e43b19c0e38880d0c636aad60
• Download URL:
  https://repository.library.noaa.gov/view/noaa/74042/noaa_74042_DS1.pdf
• File Type:
  [PDF - 6.40 MB ]