Mechanisms for Zonal Mean Wind Responses in the Thermosphere to Doubled CO ₂ Concentration

We explored mechanisms for the thermospheric zonal mean wind responses to doubled CO2 concentration through investigating momentum balance in thermosphere using GAIA model simulations June. The analysis shows that ion drag, molecular viscosity, and meridional pressure gradient force vary 3–20 times more than other forces due concentration. three strongly attenuate each other; consequently, increase drag dominantly strengthens southward (?15 ms?1 at maximum) northern (summer) hemisphere latitudes north of 35S. This strengthened was attributed increased density/relative velocity between ions neutral particles northern/southern hemisphere. Southward 35, advection strengthen by 4–12 total. On hand, is mainly altered caused a latitudinally asymmetric response density increasing Our results suggest underlying trigger Furthermore, we show (?70%) DW1 tidal component.