The excitation of the Na airglow from Coqui Dos rocket and ground-based observations

Abstract

On February 20 1998 two rockets were launched from Puerto Rico as part of the Coqui Dos campaign. Data from on-board photometers and ground-based data from a Na lidar and an airglow imager allowed an estimate to be made, using both the TIME-GCM and MSIS models, of the branching coefficient α for the Na airglow emission. Assuming the hydrogen density is within the range predicted by the two models the data are consistent with α being less than 0.05. This value is well below a recent theoretical estimate of 0.67 and also below the nominally accepted value of 0.1 derived from previous aeronomic data.