We would like to thank two referees, Drs. Xiaolei Zou and Milija Zupanski, as well as one anonymous referee for their incisive and beneficial reviews, which significantly contributed toward improving the content and presentation of this paper. We acknowledge the support from NSF Grant ATM-9731472 managed by Dr. Pamela Stephens, whom we would like to thank for her support and from the Supercomputer Computations Research Institute, which is partially funded by the Department of Energy through Contract DE-FG05-85ER250000. Acknowledgment is also made to the National Center for Atmospheric Research, which is sponsored by the National Science Foundation, for providing the computing time used in this research.
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