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Scott England

Publications and source records attributed to Scott England.

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

Tidal Effects on the Longitudinal Structures of the Martian Thermosphere and Topside Ionosphere Observed by MAVEN

Longitudinal structures in the Martian thermosphere and topside ionosphere between 150 and 200 km altitudes are studied using in situ electron and neutral measurements from the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. Four time intervals are selected for comparison, during which MAVEN sampled similar local time (9.3–10.3 h) and latitude (near 20°S) regions but at different solar longitude positions (two near northern summer solstice, one each at northern vernal and autumnal equinoxes). Persistent and pronounced tidal oscillations characterize the ionosphere and thermosphere, whose longitudinal variations in density are generally in-phase with each other. Our analysis of simultaneous and collocated neutral and electron data provides direct observational evidence for thermosphere-ionosphere coupling through atmospheric tides. We conclude that the ionosphere is subject to modulation by upward-propagating thermal tides, via both tide-induced vertical displacement and photochemical reactions. Atmospheric tides constitute a ubiquitous and significant perturbation source to the ionospheric electron density, up to ∼15% near 200 km.

Xiaohua Fang↗
NASA NTRSDate not supplied

Thermospheric Temperature and Density Variations From Observations and Models

The Global-scale Observations of the Limb and Disk (GOLD)mission in geostationary orbit provides a near synoptic (i.e. concurrent, globally unified, and spatially resolved) view of the thermosphere and ionosphere, allowing to unambiguously distinguish temporal and spatial variations. We have analyzed the thermospheric daytime temperature and column integrated O/N ratio data from GOLD, and compared these observations with the simulation results by NCAR's WACCM-X model and NRL'sMSIS2.0 model. A seasonal pattern is seen, and there are also significant differences between the observations and simulations.

Guiping Liu↗