HAO Colloquium - Climatology of Atmospheric Tides and Small-Scale Perturbations from ICON-MIGHTI

Speaker: Chihoko Cullens, CU Boulder, LASP

This work presents the first seasonal variations of small-scale perturbations from 90 km to 250 km using both temperature and winds in the latitude range of 0°-40°N. The Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI) instrument on the Ionospheric Connection Explorer (ICON) has been providing zonal and meridional winds from 95 km to 300 km and temperature measurements from 90 to 105 km since December 2019. Small-scale perturbations (< wavenumber 4) are extracted from MIGHTI temperature and wind profiles. Both small-scale perturbations from temperature and winds show consistent semi-annual variations from 90 to 250 km. Amplitudes of small-scale perturbations in the temperature and Greenline zonal winds are larger at 0°-15°N than those at 30°-40°N, and redline small-scale perturbations show similar variations between the equator area (0°-15°N) to mid-latitudes (30°-40°N). Semi-annual and altitude variations of small-scale perturbations can be explained by source variation indicated by precipitations and changes in wave propagations indicated by changes in background winds and convective instabilities. Hough Mode Extension (HME) obtained from MIGHTI tides will be presented, and potential connection of tides to changes in small-scale perturbations will be discussed using HME data. 

Date and time: 
Wednesday, November 10, 2021 - 2:00pm to 3:00pm