### Abstract

Using airborne Doppler radar data from 39 flights into hurricanes from 2004 to 2010, the authors examine the outward slope of the eyewall, revisiting the recent studies of Stern and Nolan. The slope of the radius of maximum winds (RMW) is found to increase nearly linearly with size and is uncorrelated with intensity. The slope of the eyewall absolute angular momentum surfaceMincreases with increasing size (strong correlation) and decreases with increasing intensity (weak to moderate correlation). Two other measures of eyewall slope are also investigated: the 20-dBZ reflectivity isosurface (dBZ20) and the radius of maximum azimuthal-mean updraft (RWMAX). The slopes of both dBZ20 and RWMAX increase with their size. The slope of dBZ20 decreases with intensity, though the correlation is weak, while the slope of RWMAX is uncorrelated with intensity. The absolute angular momentum decreases on average along the RMW by 9% from 2- to 8-km heights. With this larger dataset, the previous results are generally confirmed: the slope of the eyewall is mostly a function of the size of the RMW. The vertical decay rate of the maximum tangential winds (Vmax) is also reexamined. On average, Vmax decreases by 20% from 2- to 8-km heights, but this varies from 8% to as large as 42%. This percentage decay rate increases with increasing size and decreases with increasing intensity. Three cases are found where Vmax increases with height from 2 to 4km, which is likely a consequence of unbalanced flow.

Original language | English (US) |
---|---|

Pages (from-to) | 2747-2762 |

Number of pages | 16 |

Journal | Journal of the Atmospheric Sciences |

Volume | 71 |

Issue number | 7 |

DOIs | |

State | Published - 2014 |

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### ASJC Scopus subject areas

- Atmospheric Science

### Cite this

*Journal of the Atmospheric Sciences*,

*71*(7), 2747-2762. https://doi.org/10.1175/JAS-D-13-0302.1

**An expanded dataset of hurricane eyewall sizes and slopes.** / Stern, Daniel P.; Brisbois, James R.; Nolan, David S.

Research output: Contribution to journal › Article

*Journal of the Atmospheric Sciences*, vol. 71, no. 7, pp. 2747-2762. https://doi.org/10.1175/JAS-D-13-0302.1

}

TY - JOUR

T1 - An expanded dataset of hurricane eyewall sizes and slopes

AU - Stern, Daniel P.

AU - Brisbois, James R.

AU - Nolan, David S

PY - 2014

Y1 - 2014

N2 - Using airborne Doppler radar data from 39 flights into hurricanes from 2004 to 2010, the authors examine the outward slope of the eyewall, revisiting the recent studies of Stern and Nolan. The slope of the radius of maximum winds (RMW) is found to increase nearly linearly with size and is uncorrelated with intensity. The slope of the eyewall absolute angular momentum surfaceMincreases with increasing size (strong correlation) and decreases with increasing intensity (weak to moderate correlation). Two other measures of eyewall slope are also investigated: the 20-dBZ reflectivity isosurface (dBZ20) and the radius of maximum azimuthal-mean updraft (RWMAX). The slopes of both dBZ20 and RWMAX increase with their size. The slope of dBZ20 decreases with intensity, though the correlation is weak, while the slope of RWMAX is uncorrelated with intensity. The absolute angular momentum decreases on average along the RMW by 9% from 2- to 8-km heights. With this larger dataset, the previous results are generally confirmed: the slope of the eyewall is mostly a function of the size of the RMW. The vertical decay rate of the maximum tangential winds (Vmax) is also reexamined. On average, Vmax decreases by 20% from 2- to 8-km heights, but this varies from 8% to as large as 42%. This percentage decay rate increases with increasing size and decreases with increasing intensity. Three cases are found where Vmax increases with height from 2 to 4km, which is likely a consequence of unbalanced flow.

AB - Using airborne Doppler radar data from 39 flights into hurricanes from 2004 to 2010, the authors examine the outward slope of the eyewall, revisiting the recent studies of Stern and Nolan. The slope of the radius of maximum winds (RMW) is found to increase nearly linearly with size and is uncorrelated with intensity. The slope of the eyewall absolute angular momentum surfaceMincreases with increasing size (strong correlation) and decreases with increasing intensity (weak to moderate correlation). Two other measures of eyewall slope are also investigated: the 20-dBZ reflectivity isosurface (dBZ20) and the radius of maximum azimuthal-mean updraft (RWMAX). The slopes of both dBZ20 and RWMAX increase with their size. The slope of dBZ20 decreases with intensity, though the correlation is weak, while the slope of RWMAX is uncorrelated with intensity. The absolute angular momentum decreases on average along the RMW by 9% from 2- to 8-km heights. With this larger dataset, the previous results are generally confirmed: the slope of the eyewall is mostly a function of the size of the RMW. The vertical decay rate of the maximum tangential winds (Vmax) is also reexamined. On average, Vmax decreases by 20% from 2- to 8-km heights, but this varies from 8% to as large as 42%. This percentage decay rate increases with increasing size and decreases with increasing intensity. Three cases are found where Vmax increases with height from 2 to 4km, which is likely a consequence of unbalanced flow.

UR - http://www.scopus.com/inward/record.url?scp=84903887456&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84903887456&partnerID=8YFLogxK

U2 - 10.1175/JAS-D-13-0302.1

DO - 10.1175/JAS-D-13-0302.1

M3 - Article

AN - SCOPUS:84903887456

VL - 71

SP - 2747

EP - 2762

JO - Journals of the Atmospheric Sciences

JF - Journals of the Atmospheric Sciences

SN - 0022-4928

IS - 7

ER -