Vertical Distribution of Radar Reflectivity in Hurricanes in the Presence of Shear
Image: NASA
Black et al., 2002 modified by Houze 2009
DL
UR DR
UL
Quantifying Vertical Structure
• Hence and Houze 2011, 2012 (a,b) analyzed data from TRMM PR– Snapshots of radar reflectivity– 10+ years of data– Contoured by Frequency Altitude Diagrams
(CFADs)• 200-850hPa shear from NCEP
Hence and Houze 2011 Reflectivity (dBZ)
Heig
ht (k
m)
Hence and Houze 2011
Heig
ht (k
m)
Reflectivity (dBZ)30 3040 40
2
2
6
6
8
8DL DR
URUL
Shea
r
Courtesy of D. Hence
Field Campaigns• RAINEX (2005)– Katrina: 8/28– NOAA 43
• IFEX/GRIP (2010)– Earl: 8/29, 8/30, 9/1, 9/2– NOAA 42 & 43
Hurricane Katrina – 8/28/2005
Shea
r
Shea
r
Hurricane Earl – 8/30/2010
Shea
r
Hurricane Earl – 8/30/2010
Shea
r
Conclusions
• Structures of Katrina and Earl at strong intensities share similarities with statistics– Intense low-level reflectivities
• Early sampling of Earl on 8/30 did not– Shear calculation issue?– Rapid Intensification?– Circulation pattern?
EndThis research was supported by NSF grant # ATM-0743180 and NASA grant #NNX09AM73G
