Horizontal Internal Gravity Waves in the Mars Upper Atmosphere From MAVEN ACC and NGIMS Measurements

摘要

Internal gravity waves (IGWs) play an important role in the planetary atmospheres, which transfer energy and momentum from the lower layers to the upper atmosphere. However, the IGW perturbations and behaviors are not clear in the Mars upper atmosphere, particularly for the horizontal internal gravity waves (hIGWs). In this study, the hIGWs in the upper atmosphere of Mars are estimated and investigated for the first time using both accelerometer (ACC)-derived mass density and Neutral Gas and Ion Mass Spectrometer-measured neutral density from Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. The results show that the amplitudes of hIGWs variations are significantly affected by the dust storms and increase with the altitudes. The larger amplitudes are triggered in Martian Year (MY) 34 during a global dust event. The characteristics of Ar and CO_2 hIGWs variations are similar. Furthermore, the trend of the CO perturbations seems to follow the CO_2. However, the dust storms play little role in shaping hIGWs of atomic O. The hIGWs show the stable waveform with the increasing altitudes.