Seasonal and local time variations in the O( 1S) green line, O 2 atmospheric band, and OH Meinel band emissions as measured by the High Resolution Doppler Imager

Abstract

The High Resolution Doppler Imager (HRDI) instrument on the Upper Atmosphere Research Satellite (UARS) has been collecting nearly simultaneous altitude profiles of the O( 1S), O 2( 1Σ) , and OH (9-4) Meinel band emissions in the mesosphere and lower thermosphere (MLT) region during the nighttime portion of the satellite orbit since March of 1994. The length of the data record permits seasonal variations of the emissions to be examined and correlated with seasonal changes in the tidal influence of the wind field. The UARS spacecraft precesses in local time so that all nighttime hours are covered every 36 days. The volume emission rate profile can therefore be mapped as a function of local time and latitude approximately every month. This paper discusses the retrievel method, presents the height and brightness variations of the three emissions for one year of data and shows the local time variation of the OH (9-4) emission during March–April, 1994.