Vorticity-Based Detection of Tropical Cyclogenesis

Abstract Ocean wind vectors from the SeaWinds scatterometer aboard the Quick Scatterometer (QuikSCAT) satellite and Geostationary Operational Environmental Satellite (GOES) imagery are used to develop an objective technique that can detect and monitor tropical disturbances associated with the early stages of tropical cyclogenesis in the Atlantic basin. The technique is based on identification of surface vorticity and wind speed signatures that exceed certain threshold magnitudes, with vorticity averaged over an appropriate spatial scale. The threshold values applied herein are determined from the precursors of 15 tropical cyclones during the 1999–2004 Atlantic Ocean hurricane seasons using research-quality QuikSCAT data. The choice of these thresholds is complicated by the lack of suitable validation data. The combination of GOES and QuikSCAT data is used to track the tropical disturbances that are precursors to the 15 tropical cyclones. This combination of data can be used to test detection but is not as...

[1]  Christopher A. Davis.  Numerical simulations of the genesis of Hurricane Diana (1984) [presentation] , 2001 .

[2]  Stephen L. Richards,et al.  A Field-Wise Retrieval Algorithm for SeaWinds , 2003 .

[3]  C. Craeye,et al.  Scatterometric signatures of multivariate drop impacts on fresh and salt water surfaces , 1999 .

[4]  B. Farrell,et al.  Tropical Cyclone Formation , 1993 .

[5]  T. Carlson.  SYNOPTIC HISTORIES OF THREE AFRICAN DISTURBANCES THAT DEVELOPED INTO ATLANTIC HURRICANES , 1969 .

[6]  Donald C. Norquist,et al.  The Structure and Properties of African Wave Disturbances as Observed During Phase III of GATE , 1977 .

[7]  J. Franklin,et al.  Atlantic Hurricane Season of 2007 , 2008 .

[8]  P. Sobieski,et al.  An Analysis of Scatterometer Returns From a Water-surface Agitated By Artificial Rain - Evidence That Ring-waves Are the Main Feature , 1993 .

[9]  Mark A. Bourassa,et al.  Calibrating the Quikscat/SeaWinds Radar for measuring rainrate over the oceans , 2003, IEEE Trans. Geosci. Remote. Sens..

[10]  Robert W. Burpee.  Characteristics of North African Easterly Waves During the Summers of 1968 and 1969 , 1974 .

[11]  Lance F. Bosart,et al.  The Role of Synoptic-Scale Flow during Tropical Cyclogenesis over the North Atlantic Ocean , 2000 .

[12]  Kerry A. Emanuel,et al.  The Genesis of Hurricane Guillermo: TEXMEX Analyses and a Modeling Study , 1997 .

[13]  Melville E. Nicholls,et al.  A Vortical Hot Tower Route to Tropical Cyclogenesis. , 2006 .

[14]  Mark A. Bourassa,et al.  Effects of Rain Rate and Wind Magnitude on SeaWinds Scatterometer Wind Speed Errors , 2002 .

[15]  Robert W. Burpee.  Some Features of Synoptic–Scale Waves Based on a Compositing Analysis of GATE Data , 1975 .

[16]  Scatterometry of a Drop Impact On a Salt-water Surface , 1995 .

[17]  B. Hoskins,et al.  An idealized study of African easterly waves. I: A linear view , 1994 .

[18]  David G. Long,et al.  Simultaneous wind and rain retrieval using SeaWinds data , 2004, IEEE Transactions on Geoscience and Remote Sensing.

[19]  J. O'Brien,et al.  Scatterometry Data Sets : High Quality Winds Over Water , 2002 .

[20]  Carl A. Mears,et al.  Advanced algorithms for QuikScat and SeaWinds/AMSR , 2001, IGARSS 2001. Scanning the Present and Resolving the Future. Proceedings. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217).

[21]  Miles B. Lawrence,et al.  The Atlantic Hurricane Season , 1985 .

[22]  M. Montgomery,et al.  Tropical Cyclogenesis via Convectively Forced Vortex Rossby Waves in a Three-Dimensional Quasigeostrophic Model , 1998 .

[23]  Elizabeth A. Ritchie,et al.  Scale interactions during the formation of typhoon irving , 1997 .

[24]  Mark A. Bourassa,et al.  EARLY DETECTION OF TROPICAL CYCLONES USING SEAWINDS-DERIVED VORTICITY , 2001 .

[25]  Christopher A. Davis,et al.  The Role of “Vortical” Hot Towers in the Formation of Tropical Cyclone Diana (1984) , 2004 .

[26]  W. Timothy Liu,et al.  QuikSCAT's sea winds facilitates early identification of tropical depressions in 1999 hurricane season , 2001 .

[27]  Robert W. Burpee.  The Origin and Structure of Easterly Waves in the Lower Troposphere of North Africa , 1971 .

[28]  David G. Long,et al.  A median-filter-based ambiguity removal algorithm for NSCAT , 1991, IEEE Trans. Geosci. Remote. Sens..

[29]  Herbert Riehl,et al.  Climate and weather in the tropics , 1979 .

[30]  Edward N. Rappaport,et al.  Atlantic Hurricane Season of 1994 , 1996 .

[31]  R. Elsberry,et al.  A global view of tropical cyclones , 1987 .

[32]  Richard J. Pasch,et al.  Atlantic Tropical Systems of 1991 , 1992 .

[33]  K. Emanuel,et al.  An Air–Sea Interaction Theory for Tropical Cyclones. Part II: Evolutionary Study Using a Nonhydrostatic Axisymmetric Numerical Model , 1987 .

[34]  David G. Long,et al.  Spaceborne radar measurement of wind velocity over the ocean-an overview of the NSCAT scatterometer system , 1991, Proc. IEEE.

[35]  Lance F. Bosart,et al.  Mesoscale Observations of the Genesis of Hurricane Dolly (1996) , 2005 .

[36]  M. Donelan,et al.  Radar scattering and equilibrium ranges in wind‐generated waves with application to scatterometry , 1987 .

[37]  Elizabeth A. Ritchie,et al.  Mesoscale Interactions in Tropical Cyclone Genesis , 1997 .

[38]  Christopher A. Davis,et al.  Numerical Simulations of the Genesis of Hurricane Diana (1984). Part I: Control Simulation , 2000 .

[39]  Frank J. Wentz,et al.  A model function for the ocean‐normalized radar cross section at 14 GHz derived from NSCAT observations , 1999 .

[40]  L. Bosart,et al.  The Johnstown Flood of July 1977: A Long-Lived Convective System , 1981 .