Abstract
Hurricanes extract energy from the warm ocean through enthalpy fluxes. As part of the Coupled Boundary Layer Air-Sea Transfer (CBLAST) experiment, flights were conducted to measure turbulent fluxes in the high-wind boundary layer of hurricanes. Here we present the first field observations of sensible heat and enthalpy flux for 10m wind speeds to 30 ms-1. The analyses indicate no statistically significant dependence of these bulk exchange coefficients on wind speed. As a measure of hurricane development potential, we compute the mean ratio of the exchange coefficient for enthalpy to that for momentum and find it to be significantly below the lowest threshold estimated by previous investigators. This suggests that the enthalpy flux required for hurricane development may come from sources other than turbulent fluxes, such as lateral fluxes from the vortex warm core, or sea spray. Alternatively, it demands a re-evaluation of the theoretical models used to derive the threshold.
| Original language | English (US) |
|---|---|
| Article number | L14813 |
| Journal | Geophysical Research Letters |
| Volume | 35 |
| Issue number | 14 |
| DOIs | |
| State | Published - Jul 28 2008 |
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ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
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First direct measurements of enthalpy flux in the hurricane boundary layer : The CBLAST results. / Zhang, Jun A.; Black, Peter G.; French, Jeffrey R.; Drennan, William M.
In: Geophysical Research Letters, Vol. 35, No. 14, L14813, 28.07.2008.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - First direct measurements of enthalpy flux in the hurricane boundary layer
T2 - The CBLAST results
AU - Zhang, Jun A.
AU - Black, Peter G.
AU - French, Jeffrey R.
AU - Drennan, William M
PY - 2008/7/28
Y1 - 2008/7/28
N2 - Hurricanes extract energy from the warm ocean through enthalpy fluxes. As part of the Coupled Boundary Layer Air-Sea Transfer (CBLAST) experiment, flights were conducted to measure turbulent fluxes in the high-wind boundary layer of hurricanes. Here we present the first field observations of sensible heat and enthalpy flux for 10m wind speeds to 30 ms-1. The analyses indicate no statistically significant dependence of these bulk exchange coefficients on wind speed. As a measure of hurricane development potential, we compute the mean ratio of the exchange coefficient for enthalpy to that for momentum and find it to be significantly below the lowest threshold estimated by previous investigators. This suggests that the enthalpy flux required for hurricane development may come from sources other than turbulent fluxes, such as lateral fluxes from the vortex warm core, or sea spray. Alternatively, it demands a re-evaluation of the theoretical models used to derive the threshold.
AB - Hurricanes extract energy from the warm ocean through enthalpy fluxes. As part of the Coupled Boundary Layer Air-Sea Transfer (CBLAST) experiment, flights were conducted to measure turbulent fluxes in the high-wind boundary layer of hurricanes. Here we present the first field observations of sensible heat and enthalpy flux for 10m wind speeds to 30 ms-1. The analyses indicate no statistically significant dependence of these bulk exchange coefficients on wind speed. As a measure of hurricane development potential, we compute the mean ratio of the exchange coefficient for enthalpy to that for momentum and find it to be significantly below the lowest threshold estimated by previous investigators. This suggests that the enthalpy flux required for hurricane development may come from sources other than turbulent fluxes, such as lateral fluxes from the vortex warm core, or sea spray. Alternatively, it demands a re-evaluation of the theoretical models used to derive the threshold.
UR - http://www.scopus.com/inward/record.url?scp=53749097212&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=53749097212&partnerID=8YFLogxK
U2 - 10.1029/2008GL034374
DO - 10.1029/2008GL034374
M3 - Article
AN - SCOPUS:53749097212
VL - 35
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 14
M1 - L14813
ER -