On the consistency of model, ground‐based, and satellite observations of tidal signatures: Initial results from the CAWSES tidal campaigns

Abstract

Comparisons between tidal wind signatures diagnosed from satellite and ground‐based observations and a general circulations model for two (September–October 2005, March–April 2007) of the four Climate and Weather of the Sun‐Earth System (CAWSES) Global Tidal Campaign observation periods are presented (CAWSES is an international program sponsored by Scientific Committee on Solar‐Terrestrial Physics). Specific comparisons are made between model (extended Canadian Middle Atmosphere Model), satellite (Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED)), meteor, MF and incoherent scatter radar (ISR), and lidar tidal signatures in the mesosphere and lower thermosphere. The satellite and ground‐based signatures are in good agreement and demonstrate for the first time that the tidal wind fields observed by both types of observations are consistent with each other. This is the first time that such agreement has been reported and effectively resolves the long‐standing issue between ground‐based radar and satellite optical measurements of winds. This level of agreement, which has proved elusive in the past, was accomplished by superposing the significant tidal components from the satellite analyses to reconstruct the fields observed by the ground stations. Particularly striking in these comparisons is the extent to which the superposed fields show strong geographic variability. This variability is also seen in the component superpositions generated from the extended Canadian Middle Atmosphere Model (eCMAM), although differences in the geographic patterns are evident.