Satellite-Based Correlation Studies of Mesospheric O2 and OH Infrared Emissions

The Mesosphere and Lower Thermosphere/Ionosphere (MLTI) plays an important role in the energy balance of the Earth-Sun planetary system. The SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument on NASAs TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) satellite is a spatially scanning 10-channel infrared radiometer. To aid in the modeling of the photo-chemical dynamics that take place in the MLTI region, a series of correlations concerning three radiometric airglow bands of SABER are explored. The three bands of interest are O2(14g), OH(9-7;8-6) and OH(5-3), centered at wavelengths of 1.27, 2.06 and 1.64 μm, respectively. It was found that both the O2(14g) and OH(4v = 2) nighttime airglow volume emission rates have consistently brighter values and lower altitudes at near equatorial latitudes compared with values at midlatitudes. Two correlations are presented herein: (1) latitudinal and (2) global. The correlations performed showed consistent results. The more reliable results come from the global correlation using a binning technique that allowed for more data. The binning technique also made it possible to view the correlations over the entire globe. The dual OH airglow bands exhibited a strong correlation (0.85 to 1.0). The O2 1.27 μm airglow band showed a strong correlation (0.8 to 1.0) with the OH 2.06 μm airglow band. The O2 1.27 μm airglow band is less correlated (0.6 to 0.8) with the OH 1.64 μm airglow band