Shear-Relative Asymmetric Kinematic Characteristics of Intensifying Hurricanes as Observed by Airborne Doppler Radar

Details

• Journal Title:
  Monthly Weather Review
• Personal Author:
  Shimada, Udai ; Reasor, Paul D. ; Rogers, Robert F. ; Fischer, Michael S. ; Marks, Frank D. ; Zawislak, Jonathan A. ; Zhang, Jun A.
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; AOML (Atlantic Oceanographic and Meteorological Laboratory) ; CIMAS (Cooperative Institute for Marine and Atmospheric Studies)
• Description:
  While recent observational studies of intensifying (IN) versus steady-state (SS) hurricanes have noted several differences in their axisymmetric and asymmetric structures, there remain gaps in the characterization of these differences in a fully three-dimensional framework. To address these limitations, this study investigates differences in the shear-relative asymmetric structure between IN and SS hurricanes using airborne Doppler radar data from a dataset covering an extended period of time. Statistics from individual cases show that IN cases are characterized by peak wavenumber-1 ascent concentrated in the upshear-left (USL) quadrant at ∼12-km height, consistent with previous studies. Moderate updrafts (2–6 m s−1) occur more frequently in the downshear eyewall for IN cases than for SS cases, likely leading to a higher frequency of moderate to strong updrafts USL above 9-km height. Composites of IN cases show that low-level outflow from the eye region associated with maximum wavenumber-1 vorticity inside the radius of maximum wind (RMW) in the downshear-left quadrant converges with low-level inflow outside the RMW, forming a stronger local secondary circulation in the downshear eyewall than SS cases. The vigorous eyewall convection of IN cases produces a net vertical mass flux increasing with height up to ∼5 km and then is almost constant up to 10 km, whereas the net vertical mass flux of SS cases decreases with height above 4 km. Strong USL upper-level ascent provides greater potential for the vertical development of the hurricane vortex, which is argued to be favorable for continued intensification in shear environments.
• Keywords:
  Atmospheric Science
• Source:
  Monthly Weather Review, 152(2), 491-512
• DOI:
  https://doi.org/10.1175/MWR-D-22-0340.1
• 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:ba9d813a33e36bc89b79d3e42baa0bd315c726c21d9ad52fa16ee8baeacfe60115fd282454fe7b19e9bdb1fbca49fce1bb8dec805aaef2f02275806cd1cf980e
• Download URL:
  https://repository.library.noaa.gov/view/noaa/56744/noaa_56744_DS1.pdf
• File Type:
  [PDF - 5.74 MB ]