Seasonal Variation of Thermospheric Composition Observed by NASA GOLD | CU Experts

; We examine characteristics of the seasonal variation of thermospheric; composition using column number density ratio; ∑; ; O/N; 2; ; observed by the NASA Global Observations of; Limb and Disk (GOLD) mission from low-mid to mid-high latitudes. We; found that the; ; ∑O/N; 2; ; seasonal variation is; hemispherically asymmetric: in the southern hemisphere, it exhibits the; well-known annual and seminal pattern, with highs near the equinoxes,; and primary and secondary lows near the solstices. In the northern; hemisphere, it is dominated by an annual variation, with a minor; semiannual component with the highs shifting towards the wintertime. We; also found that the durations of the December and June solstice seasons; in terms of; ; ∑O/N; 2; ; are highly variable with; longitude. Our hypothesis is that ion-neutral collisional heating in the; equatorial ionization anomaly region, ion drag, and auroral Joule; heating play substantial roles in this longitudinal dependency. Finally,; the rate of change in ∑; ; O/N; 2; ; from one solstice; season to the other is dependent on latitude, with more dramatic changes; at higher latitudes.;

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