The Role of Ground Based Radar Observations in Understanding Atmospheric Tides

Atmospheric tides and gravity waves are important circulation features that couple energy and momentum between the lower and upper atmosphere. Our understanding of the generation and propagation of these waves has led to major advances in numerical models and has been possible through the development of ground-based radar techniques and space-based emission techniques that can sense the dynamics of the upper atmosphere. Marvin Geller has played a critical role in the observational and science programs that have provided insight into the global and local processes of tides from the Middle Atmosphere Program (MAP) to the Climate and Weather in the Sun-Earth System (CAWSES) program. One of the key early aspects of his work was enabled through the coordination of the many individual ground-based radar systems that were the only observational technique that could capture the signatures of these upper atmospheric motions. The combination of these coordinated local observations with the later development of satellite based observations led to major new capabilities in process understanding and numerical model development. An examination of the history of the role of radar observations and how they contributed to our current amazing understanding and modeling of atmospheric wave coupling will demonstrate the significant contributions of Marvin Geller's work.