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We use multi‐year observations of cross‐track winds (u) from the CHAllenging Minisatellite Payload (CHAMP) and the Gravity Field and Steady State Ocean Circulation Explorer (GOCE) to calculate third‐order structure functions in the thermosphere as a function of horizontal separation (s). They are computed using the mean (〈δu3〉) and the median 〈δu3〉med $\left({\langle \delta {u}^{3}\rangle }_{\text{med}}\right)$ and implemented over non‐polar satellite paths in both hemispheres. On height averages, 〈δu3〉 is shown to scale with s2 for s ≃ 80–1,000 km, in agreement with equivalent estimates in the lower atmosphere from aircraft observations. Conversely, 〈δu3〉med ${\langle \delta {u}^{3}\rangle }_{\text{med}}$ follows an s3 power law for almost the whole s range, consistent with the two‐dimensional turbulence scaling law for a direct enstrophy cascade. These scaling laws appear independent of winds in distinct atmospheric regions. Furthermore, the functions are predominantly positive, indicating a preferential cyclonic motion for the wind. Plain Language Summary: The dynamics of upper atmosphere winds differ significantly from those at lower altitudes, with larger magnitudes and increased sensitivity to solar events. Satellites, especially those in polar orbits, offer an effective means of studying these winds, particularly their East‐West component. To mitigate the chaotic nature of individual measurements influenced by various physical processes, it is common to compute wind averages. A particular way of doing this is by calculating the so‐called third‐order structure functions (SFs), a statistical quantity that provides information on the underlying turbulence processes. The third‐order SFs of satellites' zonal wind observations present two main characteristics. First, they are consistently positive, predicting a preferential cyclonic rotational motion. This is, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Second, and more importantly, the functions display the same type of dependence on the horizontal distance as third‐order SFs of winds in the lower atmosphere. This suggests that similar underlying large‐scale turbulence mechanisms may be at play. Key Points: Third‐order structure functions of zonal winds in the thermosphere at mid‐ and low‐ to mid‐latitudes are calculatedMeso‐ and Synoptic‐scale structures share a preferential cyclonic motion in the thermosphereMeasured scaling laws of third‐order structure functions seem to be independent of the atmospheric region [ABSTRACT FROM AUTHOR]

Thermosphere cooling is a known effect of increasing CO2 in the atmosphere. In this study, we explore the changes of thermosphere circulation and tides in the cooled thermosphere via a doubled CO2 numerical experiment using the Ground‐to‐topside Atmosphere Ionosphere model for Aeronomy (GAIA). The results reveal three major features. (1) The thermosphere cools about 10 K more around solstices than equinoxes, more at the summer pole than the winter pole. (2) The meridional circulation shifts downward and strongly accelerates by 5–15 m s−1. (3) The tidal activity experiences dramatic changes, with a 40–60% reduction in the semidiurnal tides (SW2) throughout the thermosphere but an 30–50% enhancement in diurnal tides (DW1) below 200 km altitude. The nonmigrating tide DE3 has only minor changes. These changes in temperature, meridional circulation, and tides are persistent features in all seasons and can profoundly affect the spatial distribution and diurnal cycles of the ionospheric responses to CO2 doubling via atmosphere composition and electrodynamics. Key Points: Thermosphere cooling is stronger around solstice than equinoxesThe meridional circulation is accelerated by 5–15 m/sSemidiurnal tides are strongly reduced [ABSTRACT FROM AUTHOR]