Comparison of ICON/MIGHTI and TIMED/SABER Neutral Temperature Measurements at Conjunctions in the Lower Thermosphere

Abstract This study presents a cross‐comparison of mesosphere and lower thermosphere (MLT) neutral temperatures between 88 and 110 km measured by ICON/Michelson Interferometer for Global High‐resolution Thermospheric Imaging (MIGHTI) and Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) from 2020 to 2022. We analyzed MIGHTI Level‐2.3 (v06) and SABER Level‐2.08 (v02) data, identifying conjunctions using local time 15 min, latitude 2°, and longitude 4° around each SABER measurement. Due to their orbital geometries, frequent conjunctions occurred between MIGHTI and SABER, widely distributed in longitude but nearly locked in local time and latitude, enabling direct comparison of daily longitudinal temperature variability at fixed local time and latitude between 88 and 110 km. Daily temperature structures from MIGHTI and SABER show excellent agreement, capturing coherent longitudinal oscillations with peak‐to‐trough amplitudes of ∼40–60 K likely associated with upward‐propagating non‐migrating tides and planetary waves. Statistical analyses reveal that MIGHTI daytime temperatures are more correlated (∼0.82) than nighttime (∼0.74) with MIGHTI daytime temperatures consistently warmer than SABER and the difference increasing with altitude from ∼3 K at 88–95 km to ∼26 K at 105–110 km. Nighttime differences are statistically insignificant. Mean absolute residuals show a clear diurnal behavior, peaking at daytime and minimizing at nighttime. Residuals exhibit seasonal dependence but no particular systematic latitudinal and longitudinal dependence. This study compares MIGHTI and SABER temperatures to clarify their similarities and differences, an understanding that is important for interpreting global MLT tidal behavior from space‐based observations; it does not seek to demonstrate which instrument provides more accurate absolute MLT temperatures.