This work was partially supported by a Department of Energy grant from the Atmospheric Radiation Measurement project, a National Science Foundation TOGA COARE grant, and the JAMSTEC Tropical Ocean Climate Study project. The authors would like to express their special thanks to G. Kiladis, K. Weickmann, and K. Gage of NOAA/Aeronomy Laboratory; B. Mapes of the University of Colorado; R. Johnson and P. Ciesielski of Colorado State University (CSU); H.-W. Kuo and A. Kasahara of NCAR; Y. Kuroda and K. Ando of JAMSTEC; and the three anonymous reviewers for their valuable suggestions and critical comments. Thanks are extended to S. Trier of NCAR, who provided the original program to calculate the vertical wind component. They express their gratitude to N. Sakata and M. A. Pykkonen for their assistance with the preparation of this manuscript. J. Lukas provided expert technical editing. The research was initiated when the first author was visiting NCAR/Atmospheric Technology Division/Surface and Sounding Systems Facility. He deeply appreciates the encouragement of D. Carlson, the director of ATD, and SSSF members. The study was completed while the second author was on a sabbatical at the Centre National des Recherches Meteorologiques in Toulouse, France. He is indebted to CNRM/Météo France for this opportunity. Useful discussions with J.-L. Redelsperger and J.-P. LaFore led to the proposed mechanism. Communications with W. Schubert of CSU also proved useful in understanding the wave breaking process. Both authors would also like to thank their families for agreeing to spend time abroad away from their relatives and friends, which allowed this work to be undertaken and completed.
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