Atomic Oxygen Depletion Measurements in a Diffuse Aurora

The Coupling of Dynamics and Aurora (CODA) Payload was launched at 06:20 LT on January 22, 1999 from Poker Flat, Alaska and again at 0:55 LT on February 21, 2001. Atomic oxygen profiles were measured in situ by a combination of resonance and florescence techniques and reveals significant structural differences between the two flights. The second flight records a significant erosion of the top side atomic oxygen profile over a 30 km horizontal extent. One possible explanation is that turbulent mixing forced by the diffuse aurora is driving the atomic oxygen recombination rate. This data indicates the spatial scales over which composition changes can occur in the auroral regions and give insight into the O/N₂ ratios measured by GUVI on the TIMED spacecraft.