北京地区上空OH转动温度的季节性变化

Abstract: OH airglow emissions are generated in the mesopause and low thermosphere (MLT) region in a layer centered near 87km.The OH rotational temperature is a good proxy for the kinetic temperature.So the rotational temperatures derived from ground-based observations of OH airglow emissions are used to investigate the temperature structure in the MLT.The OH airglow emission spectra were observed by the ground-based spectrometer from December 2011 to December 2013.The OH (8-3) band is used to calculate rotational temperature.The temperatures from SABER are weighted vertically by the weighting functions from its OH-A channel volume emission rates.Firstly, the rotational temperature is compared with the SABER.Secondly, the daily mean temperatures are fitted by the harmonic waves, and the temporal variation features during nights are analyzed.The comparison between OH rotational temperature and SABER shows that the mean rotational temperature of OH (8-3) band is 203.011.2Kwith 5.5Kwarmer than SABER′s.Both have obviously identical seasonal variations and the temperature variation of winter to summer can reach 60K.The annual and semiannual components are the two most significant variations, and the annual amplitude of 10.8Kis greater than semiannual amplitude of 2.7K.Their phases are respectively in December and March.It is shown that there are multiple temporal rotational variations during night, such as oscillations controlled by tides and shortperiod waves.The OH rotational temperature is a good proxy for the kinetic temperature in the MLT region.There are significant annual and semiannual variations in this region, and the temperatures during night have various temporal features.It is concluded that the temporal variations of ground-based rotational temperatures from OH (8-3) band are well correlated with the SABER temperatures.They have the same seasonal variations and the annual and semiannual oscillations are the two strongest components.The nocturnal rotational temperatures have multiple temporal features controlled by the various oscillations.