Quasi-10-day waves in temperature and polar mesospheric clouds: Results of AIM/SOFIE and Aura/MLS observations

Abstract

Planetary waves, including quasi-2, -5, -10, -16-day waves, play significant roles in stratospheric dynamics. However, the existing knowledge on quasi-10-day waves (Q10DWs) at high latitudes is limited. This paper investigated the interannual and seasonal variations of Q10DWs with zonal wave numbers varying from the −3 (westward propagation) to 3 (eastward propagation) modes from 2008 to 2022, using temperature data measured by the Microwave Limb Sounder instrument (316−0.001 hPa, corresponding to an altitude of approximately 8−97 km) and temperature/ice water content data measured by the Solar Occultation for Ice Experiment (SOFIE) instrument (10−100 km at latitudes > 55°). The findings revealed that the amplitude of Q10DWs in winter was higher than that in other seasons. The amplitude of Q10DWs was observed to substantially decrease with an increase in wavenumber. In addition, the amplitude of stationary Q10DWs in the northern polar region exceeded that in the southern polar region. Moreover, we used observational data from the SOFIE instrument, which simultaneously measures temperature and ice water content (IWC) in the mesosphere, to examine the variations of Q10DWs with respect to the temperature and IWC. Our findings suggest that in the northern polar region, the maximum value of Q10DWs in IWC was occasionally observed earlier than the lowest value of Q10DWs in temperatures.