Abstract
The warm-core structure of tropical cyclones is examined in idealized simulations using the Weather Research and Forecasting (WRF) Model. The maximum perturbation temperature in a control simulation occurs in the midtroposphere (5-6 km), in contrast to the upper-tropospheric (>10 km) warm core that is widely believed to be typical. This conventional view is reassessed and found to be largely based on three case studies, and it is argued that the "typical" warm-core structure is actually not well known. In the control simulation, the height of the warm core is nearly constant over a wide range of intensities. From additional simulations in which either the size of the initial vortex or the microphysics parameterization is varied, it is shown that the warm core is generally found at 4-8 km. A secondary maximumoften develops near 13-14 km but is almost always weaker than the primary warm core. It is demonstrated that microwave remote sensing instruments are of insufficient resolution to detect this midlevel warm core, and the conclusions of some studies that have utilized these instruments may not be reliable. Using simple arguments based on thermal wind balance, it is shown that the height of the warm core is not necessarily related to either the height where the vertical shear of the tangential winds is maximized or the height where the radial temperature gradient is maximized. In particular, changes in the height of the warm core need not imply changes in either the intensity of the storm or in the manner in which the winds in the eyewall decay with height.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1657-1680 |
| Number of pages | 24 |
| Journal | Journal of the Atmospheric Sciences |
| Volume | 69 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 2012 |
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Keywords
- Tropical cyclones
ASJC Scopus subject areas
- Atmospheric Science
Cite this
On the height of the warm core in tropical cyclones. / Stern, Daniel P.; Nolan, David S.
In: Journal of the Atmospheric Sciences, Vol. 69, No. 5, 05.2012, p. 1657-1680.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - On the height of the warm core in tropical cyclones
AU - Stern, Daniel P.
AU - Nolan, David S
PY - 2012/5
Y1 - 2012/5
N2 - The warm-core structure of tropical cyclones is examined in idealized simulations using the Weather Research and Forecasting (WRF) Model. The maximum perturbation temperature in a control simulation occurs in the midtroposphere (5-6 km), in contrast to the upper-tropospheric (>10 km) warm core that is widely believed to be typical. This conventional view is reassessed and found to be largely based on three case studies, and it is argued that the "typical" warm-core structure is actually not well known. In the control simulation, the height of the warm core is nearly constant over a wide range of intensities. From additional simulations in which either the size of the initial vortex or the microphysics parameterization is varied, it is shown that the warm core is generally found at 4-8 km. A secondary maximumoften develops near 13-14 km but is almost always weaker than the primary warm core. It is demonstrated that microwave remote sensing instruments are of insufficient resolution to detect this midlevel warm core, and the conclusions of some studies that have utilized these instruments may not be reliable. Using simple arguments based on thermal wind balance, it is shown that the height of the warm core is not necessarily related to either the height where the vertical shear of the tangential winds is maximized or the height where the radial temperature gradient is maximized. In particular, changes in the height of the warm core need not imply changes in either the intensity of the storm or in the manner in which the winds in the eyewall decay with height.
AB - The warm-core structure of tropical cyclones is examined in idealized simulations using the Weather Research and Forecasting (WRF) Model. The maximum perturbation temperature in a control simulation occurs in the midtroposphere (5-6 km), in contrast to the upper-tropospheric (>10 km) warm core that is widely believed to be typical. This conventional view is reassessed and found to be largely based on three case studies, and it is argued that the "typical" warm-core structure is actually not well known. In the control simulation, the height of the warm core is nearly constant over a wide range of intensities. From additional simulations in which either the size of the initial vortex or the microphysics parameterization is varied, it is shown that the warm core is generally found at 4-8 km. A secondary maximumoften develops near 13-14 km but is almost always weaker than the primary warm core. It is demonstrated that microwave remote sensing instruments are of insufficient resolution to detect this midlevel warm core, and the conclusions of some studies that have utilized these instruments may not be reliable. Using simple arguments based on thermal wind balance, it is shown that the height of the warm core is not necessarily related to either the height where the vertical shear of the tangential winds is maximized or the height where the radial temperature gradient is maximized. In particular, changes in the height of the warm core need not imply changes in either the intensity of the storm or in the manner in which the winds in the eyewall decay with height.
KW - Tropical cyclones
UR - http://www.scopus.com/inward/record.url?scp=84864847963&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84864847963&partnerID=8YFLogxK
U2 - 10.1175/JAS-D-11-010.1
DO - 10.1175/JAS-D-11-010.1
M3 - Article
AN - SCOPUS:84864847963
VL - 69
SP - 1657
EP - 1680
JO - Journals of the Atmospheric Sciences
JF - Journals of the Atmospheric Sciences
SN - 0022-4928
IS - 5
ER -