In response



We wish to clarify the remarks concerning measurements of OH in the atmosphere during ATLAS-1 by being more specific about what was measured. The instrument ISO (Imaging Spectrometric Observatory) on ATLAS-1 made the first space-based measurements of OH density profiles in the mesosphere by observing resonance fluorescence of the OH radical in the dayglow. This also marked the first such measurement of OH in the mesosphere since Anderson's [1971] sounding rocket measurements.

We also wish to acknowledge the long history of excellent work by the Phillips Laboratory group in observations of the pure rotation and vibration-rotation emissions of the ground electronic state OH in the mesopause region.