Nitrous oxide in the tropical middle atmosphere, observed by ground‐based MM‐wave spectrometry

Measurements of stratospheric N2O were made from Mauna Kea in Hawaii in June, 1983 and in May and June, 1986, by observing thermal emission of the molecule in a rotational transition at ∼ 1 mm wavelength. Analyses of the data yield altitude profiles in the middle and upper stratosphere. Useful measurements of N2O may be made in one to two hours. The N2O profiles agree reasonably well with model predictions and with published satellite data, though we report significantly more N2O near the stratopause than shown by the satellite measurement, and significantly more N2O in the middle stratosphere than in one of the models. The discrepancy between our data and the satellite measurement may be due in part to variations induced by the solar cycle.