Extended Abstract (428K)4D.6
Mesovortices in Hurricane Isabel (2003): A comparison of satellite, radar, and photographic observations
Michael L. Black, NOAA/AOML/HRD, Miami, FL; and J. P. Dunion, J. P. Kossin, W. H. Schubert, C. S. Velden, P. G. Black, R. Zehr, and S. D. Aberson
During 12-14 September 2003 while Hurricane Isabel maintained its intensity at or near Catgeory 5, high-resolution satellite imagery revealed remarkable structure and evolution of mesovortices that appeared in Isabel’s large eye and along the inner edge of the eyewall. NOAA P3 aircraft probed Isabel during each of the 3 days as part of the Hurricane Research Division’s annual field program. The mesovortices, as viewed from the satellite, ranged in number from one to as many as eight and which were clearly rotating around the eye while undergoing considerable evolution and interaction with each other and with Isabel’s eyewall. On 12 September, one of the mesovortices was tracked for over an hour on satellite imagery and completed more than one full orbit inside the eye. This same feature was visible on PPI and RHI radar sweeps from the NOAA aircraft during a penetration and orbit of Isabel’s eye. The mesovortex was identified as the same one visible on the satellite imagery and was tracked on radar for about 1/2 hour. Digital still and video imagery are also available from the time while the aircraft was in the eye. This digital imagery shows the close-up structure of the mesovortices and Isabel’s eyewall.
The satellite imagery will be compared to the radar data and visual imagery to document the evolution of the horizontal and vertical structure of the mesovortex and it’s path around Isabel’s eye. Cell tracking from the radar and satellite imagery will give translations speed of this feature as well as other instabilities along the inner edge of the eyewall. The photographic evidence may be quite useful to investigate the connection of mesovortices to the eyewall itself.
Session 4D, tropical cyclone observations and structure II
Monday, 3 May 2004, 3:45 PM-5:15 PM, Napoleon III Room
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