Observations of wave‐driven fluctuations of OH nightglow emission from Sondre Stromfjord, Greenland

Abstract

OH nightglow emissions from the (6, 2) band were observed during February 12–14, 1986, at Sondre Stromfjord, Greenland. The data were analyzed using time series analysis techniques to determine , where ΔI and ΔT represent correlated fluctuations from the mean OH intensity (Ī) and temperature ( ) in various frequency bands. For correlated fluctuations due to measurement error, |η| < 1, while for correlated fluctuations caused by atmospheric gravity waves (AGWs) that pass through the OH emission layer the measured |η| should be generally greater than 1.5. While some of the observed OH intensity‐temperature fluctuations were correlated and had an |η| < 1, two correlated intensity‐temperature waves with periods of 4 and 2 hours were seen with an |η| > 1.5. The 4‐hour (2‐hour) period wave had an |η| equal to 3.1 ± 1.1 (1.6 ± 0.5) and a phase angle, between the intensity and temperature components, of 5° ± 23° (40° ± 20°). These results are consistent with a recent theoretical model for the passage of AGWs through an OH emission layer. Agreement is closest for the 4‐hour (2‐hour) period wave when the layer is peaked at 87 km (83 km) and the O scale height is −2.0 (−4.0km).