This work is supported by the Air Force Weather Agency. The WRFPLUS system benefitted greatly from close collaboration with Dr. Qiang Chen and his adjoint code generator. We thank Dong-Kyou Lee and Gyu-Ho Lim of Seoul National University for their comments on the manuscript and generous support through the Korea and U.S. weather and climate centers. We thank Fuqing Zhang and Jon Poterjoy of The Pennsylvania State University for their valuable suggestions and comments on the manuscript. Mary Golden helped edit the manuscript.
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