The role of nitric oxide on the zonally averaged structure of the thermosphere: Solstice conditions for solar cycle maximum

摘要: Abstract A zonally averaged chemical-dynamical model of the Earth's thermosphere is used to investigate importance nitric oxide 5.3-μm cooling in controlling dynamic structure thermosphere. The calculates circulation, temperature, major atmospheric constituents, and oddnitrogen distributions self-consistently for solstice conditions during solar cycle minimum. NO infrared competes with downward molecular conduction upper reaches a maximum ∼ 500 K day −1 near 170 km at high summer latitudes. primary effect weaken summer-to-winter latitudinal temperature gradient, which turn weakens meridional circulation. In reduces pole difference by about 45 an 8 ms reduction wind velocity. There are corresponding reductions vertical mean zonal velocities. circulation gradient results changes composition −40% O 2 +15% suggest that has important on overall thermosphere, it should be particularly geomagnetic storms when densities neutral gas increase substantially.