Convective-scale variations in the inner-core rainbands of tropical cyclones
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Convective-scale variations in the inner-core rainbands of tropical cyclones Anthony C. Didlake, Jr. and Robert A. Houze, Jr. 30 th Conference on Hurricanes and Tropical Meteorology April 17, 2012 Houze 2010
description
Convective-scale variations in the inner-core rainbands of tropical cyclones. Houze 2010. Anthony C. Didlake, Jr. and Robert A. Houze, Jr. 30 th Conference on Hurricanes and Tropical Meteorology April 17, 2012. Hurricane Rita. S t r a t i f o r m. NCAR ELDORA radar. - PowerPoint PPT Presentation
Transcript of Convective-scale variations in the inner-core rainbands of tropical cyclones
Convective-scale variations in the inner-core rainbands of
tropical cyclones
Anthony C. Didlake, Jr. and Robert A. Houze, Jr.30th Conference on Hurricanes and Tropical Meteorology
April 17, 2012
Houze 2010
NCAR ELDORA radar
9/21/2005 1845-1927 Z2 km reflectivity
C o n v e c t i v e
S t r a t i f o r m
dBZ
Hurricane Rita
Method of analysis Divide into “inner” and “outer” regions Classify pixels as “convective” or “stratiform” Take radial cross sections across convective regions
Inner
Outer
Method of analysis
Inner
Outer
Divide into “inner” and “outer” regions Classify pixels as “convective” or “stratiform” Take radial cross sections across convective regions
inner region outer region v (m/s)
Tangential wind (m/s) – Shaded contoursReflectivity (dBZ) – Contour linesSecondary circulation – Vectors
Composite cross sections
eye
inner region outer region
Tangential wind
Radial wind
v (m/s)
u (m/s)Hence and Houze 2008
inner region outer region
Tangential wind
Radial wind
v (m/s)
u (m/s)
Vertical velocity (m/s)
solid – innerdashed – outer
CAPE as a function of radius
Bogner et al. 2000
down uptotal
Alti
tude
(km
)
inner region outer regionTangential momentum tendency
blue – radial advectionred – vertical advectiongreen – Coriolis term
acceleration (m s-2) acceleration (m s-2)
Alti
tude
(km
)
Total tendencyTangential momentum tendency
acceleration (m s-2)
D red – inner black – outer
acceleration (m s-2)
Alti
tude
(km
)
9/21/2005 2010 Z
9/22/2005 1800 Z
Didlake and Houze 2012
Didlake and Houze 2011
Rainband convective cells
Secondary eyewall
Critical zone for secondary eyewall formation Strong winds and low
CAPE Confinement of jet Amplification via WISHE
feedback Inner edge subsidence
Didlake and Houze 2012
Didlake and Houze 2011
Rainband convective cells
Secondary eyewall
Conclusions Kinematic structure varies with radius Tangential jet depends on radial and
vertical advectionInner cell jets constrained to low levelsOuter cell jets occur within large range of
altitudes Convective cells can reach critical zone of
secondary eyewall formation
Acknowledgments Michael Bell Wen-Chau Lee Stacy Brodzik NDSEG Fellowship Program NSF grant ATM-0743180
